Merge pull request #11653 from Quix0r/fixes/more-type-hints

More type-hints added

src/App.php

@@ -145,7 +145,7 @@ class App
 		$this->nickname = $nickname;
 	}
 
-	public function isLoggedIn()
+	public function isLoggedIn(): bool
 	{
 		return local_user() && $this->user_id && ($this->user_id == local_user());
 	}
@@ -155,7 +155,7 @@ class App
 	 *
 	 * @return bool true if user is an admin
 	 */
-	public function isSiteAdmin()
+	public function isSiteAdmin(): bool
 	{
 		$admin_email = $this->config->get('config', 'admin_email');
 
@@ -166,18 +166,18 @@ class App
 
 	/**
 	 * Fetch the user id
-	 * @return int 
+	 * @return int User id
 	 */
-	public function getLoggedInUserId()
+	public function getLoggedInUserId(): int
 	{
 		return $this->user_id;
 	}
 
 	/**
 	 * Fetch the user nick name
-	 * @return string
+	 * @return string User's nickname
 	 */
-	public function getLoggedInUserNickname()
+	public function getLoggedInUserNickname(): string
 	{
 		return $this->nickname;
 	}
@@ -198,7 +198,7 @@ class App
 	 *
 	 * @return int
 	 */
-	public function getProfileOwner():int
+	public function getProfileOwner(): int
 	{
 		return $this->profile_owner;
 	}
@@ -219,7 +219,7 @@ class App
 	 *
 	 * @return int
 	 */
-	public function getContactId():int
+	public function getContactId(): int
 	{
 		return $this->contact_id;
 	}
@@ -241,7 +241,7 @@ class App
 	 *
 	 * @return int
 	 */
-	public function getTimeZone():string
+	public function getTimeZone(): string
 	{
 		return $this->timezone;
 	}
@@ -260,9 +260,9 @@ class App
 	/**
 	 * Fetch workerqueue information
 	 *
-	 * @return array 
+	 * @return array Worker queue
 	 */
-	public function getQueue()
+	public function getQueue(): array
 	{
 		return $this->queue ?? [];
 	}
@@ -270,8 +270,8 @@ class App
 	/**
 	 * Fetch a specific workerqueue field
 	 *
-	 * @param string $index 
+	 * @param string $index Work queue record to fetch
-	 * @return mixed 
+	 * @return mixed Work queue item or NULL if not found
 	 */
 	public function getQueueValue(string $index)
 	{
@@ -306,9 +306,9 @@ class App
 	/**
 	 * The basepath of this app
 	 *
-	 * @return string
+	 * @return string Base path from configuration
 	 */
-	public function getBasePath()
+	public function getBasePath(): string
 	{
 		// Don't use the basepath of the config table for basepath (it should always be the config-file one)
 		return $this->config->getCache()->get('system', 'basepath');
@@ -396,10 +396,10 @@ class App
 	/**
 	 * Returns the current theme name. May be overriden by the mobile theme name.
 	 *
-	 * @return string
+	 * @return string Current theme name or empty string in installation phase
 	 * @throws Exception
 	 */
-	public function getCurrentTheme()
+	public function getCurrentTheme(): string
 	{
 		if ($this->mode->isInstall()) {
 			return '';
@@ -425,10 +425,10 @@ class App
 	/**
 	 * Returns the current mobile theme name.
 	 *
-	 * @return string
+	 * @return string Mobile theme name or empty string if installer
 	 * @throws Exception
 	 */
-	public function getCurrentMobileTheme()
+	public function getCurrentMobileTheme(): string
 	{
 		if ($this->mode->isInstall()) {
 			return '';
@@ -441,12 +441,22 @@ class App
 		return $this->currentMobileTheme;
 	}
 
-	public function setCurrentTheme($theme)
+	/**
+	 * Setter for current theme name
+	 *
+	 * @param string $theme Name of current theme
+	 */
+	public function setCurrentTheme(string $theme)
 	{
 		$this->currentTheme = $theme;
 	}
 
-	public function setCurrentMobileTheme($theme)
+	/**
+	 * Setter for current mobile theme name
+	 *
+	 * @param string $theme Name of current mobile theme
+	 */
+	public function setCurrentMobileTheme(string $theme)
 	{
 		$this->currentMobileTheme = $theme;
 	}
@@ -525,10 +535,10 @@ class App
 	/**
 	 * Provide a sane default if nothing is chosen or the specified theme does not exist.
 	 *
-	 * @return string
+	 * @return string Current theme's stylsheet path
 	 * @throws Exception
 	 */
-	public function getCurrentThemeStylesheetPath()
+	public function getCurrentThemeStylesheetPath(): string
 	{
 		return Core\Theme::getStylesheetPath($this->getCurrentTheme());
 	}
@@ -730,7 +740,7 @@ class App
 	 *
 	 * @throws HTTPException\InternalServerErrorException
 	 */
-	public function redirect($toUrl)
+	public function redirect(string $toUrl)
 	{
 		if (!empty(parse_url($toUrl, PHP_URL_SCHEME))) {
 			Core\System::externalRedirect($toUrl);

src/App/Arguments.php

@@ -78,7 +78,7 @@ class Arguments
 	/**
 	 * @return string The whole command of this call
 	 */
-	public function getCommand()
+	public function getCommand(): string
 	{
 		return $this->command;
 	}
@@ -94,7 +94,7 @@ class Arguments
 	/**
 	 * @return array All arguments of this call
 	 */
-	public function getArgv()
+	public function getArgv(): array
 	{
 		return $this->argv;
 	}
@@ -102,7 +102,7 @@ class Arguments
 	/**
 	 * @return string The used HTTP method
 	 */
-	public function getMethod()
+	public function getMethod(): string
 	{
 		return $this->method;
 	}
@@ -110,7 +110,7 @@ class Arguments
 	/**
 	 * @return int The count of arguments of this call
 	 */
-	public function getArgc()
+	public function getArgc(): int
 	{
 		return $this->argc;
 	}
@@ -145,7 +145,7 @@ class Arguments
 	 *
 	 * @return bool if the argument position exists
 	 */
-	public function has(int $position)
+	public function has(int $position): bool
 	{
 		return array_key_exists($position, $this->argv);
 	}
@@ -158,7 +158,7 @@ class Arguments
 	 *
 	 * @return Arguments The determined arguments
 	 */
-	public function determine(array $server, array $get)
+	public function determine(array $server, array $get): Arguments
 	{
 		// removing leading / - maybe a nginx problem
 		$server['QUERY_STRING'] = ltrim($server['QUERY_STRING'] ?? '', '/');

src/App/BaseURL.php

@@ -107,7 +107,7 @@ class BaseURL
 	 *
 	 * @return string
 	 */
-	public function getHostname()
+	public function getHostname(): string
 	{
 		return $this->hostname;
 	}
@@ -117,7 +117,7 @@ class BaseURL
 	 *
 	 * @return string
 	 */
-	public function getScheme()
+	public function getScheme(): string
 	{
 		return $this->scheme;
 	}
@@ -127,7 +127,7 @@ class BaseURL
 	 *
 	 * @return int
 	 */
-	public function getSSLPolicy()
+	public function getSSLPolicy(): int
 	{
 		return $this->sslPolicy;
 	}
@@ -137,7 +137,7 @@ class BaseURL
 	 *
 	 * @return string
 	 */
-	public function getUrlPath()
+	public function getUrlPath(): string
 	{
 		return $this->urlPath;
 	}
@@ -151,7 +151,7 @@ class BaseURL
 	 *
 	 * @return string
 	 */
-	public function get($ssl = false)
+	public function get(bool $ssl = false): string
 	{
 		if ($this->sslPolicy === self::SSL_POLICY_SELFSIGN && $ssl) {
 			return Network::switchScheme($this->url);
@@ -168,8 +168,9 @@ class BaseURL
 	 * @param string? $urlPath
 	 *
 	 * @return bool true, if successful
+	 * @TODO Find proper types
 	 */
-	public function save($hostname = null, $sslPolicy = null, $urlPath = null)
+	public function save($hostname = null, $sslPolicy = null, $urlPath = null): bool
 	{
 		$currHostname  = $this->hostname;
 		$currSSLPolicy = $this->sslPolicy;
@@ -224,11 +225,11 @@ class BaseURL
 	/**
 	 * Save the current url as base URL
 	 *
-	 * @param $url
+	 * @param string $url
 	 *
 	 * @return bool true, if the save was successful
 	 */
-	public function saveByURL($url)
+	public function saveByURL(string $url): bool
 	{
 		$parsed = @parse_url($url);
 
@@ -421,7 +422,7 @@ class BaseURL
 	 *
 	 * @return string The cleaned url
 	 */
-	public function remove(string $origURL)
+	public function remove(string $origURL): string
 	{
 		// Remove the hostname from the url if it is an internal link
 		$nurl = Strings::normaliseLink($origURL);
@@ -445,7 +446,7 @@ class BaseURL
 	 *
 	 * @throws HTTPException\InternalServerErrorException In Case the given URL is not relative to the Friendica node
 	 */
-	public function redirect($toUrl = '', $ssl = false)
+	public function redirect(string $toUrl = '', bool $ssl = false)
 	{
 		if (!empty(parse_url($toUrl, PHP_URL_SCHEME))) {
 			throw new HTTPException\InternalServerErrorException("'$toUrl is not a relative path, please use System::externalRedirectTo");
@@ -458,8 +459,8 @@ class BaseURL
 	/**
 	 * Returns the base url as string
 	 */
-	public function __toString()
+	public function __toString(): string
 	{
-		return $this->get();
+		return (string) $this->get();
 	}
 }

src/App/Mode.php

@@ -130,7 +130,7 @@ class Mode
 	 *
 	 * @throws \Exception
 	 */
-	public function determine(BasePath $basepath, Database $database, Cache $configCache)
+	public function determine(BasePath $basepath, Database $database, Cache $configCache): Mode
 	{
 		$mode = 0;
 
@@ -178,7 +178,7 @@ class Mode
 	 *
 	 * @return Mode returns the determined mode
 	 */
-	public function determineRunMode(bool $isBackend, array $server, Arguments $args, MobileDetect $mobileDetect)
+	public function determineRunMode(bool $isBackend, array $server, Arguments $args, MobileDetect $mobileDetect): Mode
 	{
 		foreach (self::BACKEND_CONTENT_TYPES as $type) {
 			if (strpos(strtolower($server['HTTP_ACCEPT'] ?? ''), $type) !== false) {
@@ -201,7 +201,7 @@ class Mode
 	 *
 	 * @return bool returns true, if the mode is set
 	 */
-	public function has($mode)
+	public function has(int $mode): bool
 	{
 		return ($this->mode & $mode) > 0;
 	}
@@ -227,7 +227,7 @@ class Mode
 	 *
 	 * @return int Execution Mode
 	 */
-	public function getExecutor()
+	public function getExecutor(): int
 	{
 		return $this->executor;
 	}
@@ -235,9 +235,9 @@ class Mode
 	/**
 	 * Install mode is when the local config file is missing or the DB schema hasn't been installed yet.
 	 *
-	 * @return bool
+	 * @return bool Whether installation mode is active (local/database configuration files present or not)
 	 */
-	public function isInstall()
+	public function isInstall(): bool
 	{
 		return !$this->has(Mode::LOCALCONFIGPRESENT) ||
 		       !$this->has(MODE::DBCONFIGAVAILABLE);
@@ -248,7 +248,7 @@ class Mode
 	 *
 	 * @return bool
 	 */
-	public function isNormal()
+	public function isNormal(): bool
 	{
 		return $this->has(Mode::LOCALCONFIGPRESENT) &&
 		       $this->has(Mode::DBAVAILABLE) &&
@@ -261,7 +261,7 @@ class Mode
 	 *
 	 * @return bool Is it a backend call
 	 */
-	public function isBackend()
+	public function isBackend(): bool
 	{
 		return $this->isBackend;
 	}
@@ -271,7 +271,7 @@ class Mode
 	 *
 	 * @return bool true if it was an AJAX request
 	 */
-	public function isAjax()
+	public function isAjax(): bool
 	{
 		return $this->isAjax;
 	}
@@ -281,7 +281,7 @@ class Mode
 	 *
 	 * @return bool true if it was an mobile request
 	 */
-	public function isMobile()
+	public function isMobile(): bool
 	{
 		return $this->isMobile;
 	}
@@ -291,7 +291,7 @@ class Mode
 	 *
 	 * @return bool true if it was an tablet request
 	 */
-	public function isTablet()
+	public function isTablet(): bool
 	{
 		return $this->isTablet;
 	}

src/App/Page.php

@@ -195,7 +195,7 @@ class Page implements ArrayAccess
 	 * @param string $media
 	 * @see Page::initHead()
 	 */
-	public function registerStylesheet($path, string $media = 'screen')
+	public function registerStylesheet(string $path, string $media = 'screen')
 	{
 		$path = Network::appendQueryParam($path, ['v' => FRIENDICA_VERSION]);
 
@@ -288,7 +288,7 @@ class Page implements ArrayAccess
 	 *
 	 * Taken from http://webcheatsheet.com/php/get_current_page_url.php
 	 */
-	private function curPageURL()
+	private function curPageURL(): string
 	{
 		$pageURL = 'http';
 		if (!empty($_SERVER["HTTPS"]) && ($_SERVER["HTTPS"] == "on")) {

src/App/Router.php

@@ -152,7 +152,7 @@ class Router
 	 *
 	 * @throws HTTPException\InternalServerErrorException In case of invalid configs
 	 */
-	public function loadRoutes(array $routes)
+	public function loadRoutes(array $routes): Router
 	{
 		$routeCollector = ($this->routeCollector ?? new RouteCollector(new Std(), new GroupCountBased()));
 
@@ -166,6 +166,13 @@ class Router
 		return $this;
 	}
 
+	/**
+	 * Adds multiple routes to a route collector
+	 *
+	 * @param RouteCollector $routeCollector Route collector instance
+	 * @param array $routes Multiple routes to be added
+	 * @throws HTTPException\InternalServerErrorException If route was wrong (somehow)
+	 */
 	private function addRoutes(RouteCollector $routeCollector, array $routes)
 	{
 		foreach ($routes as $route => $config) {
@@ -221,7 +228,7 @@ class Router
 	 *
 	 * @return bool
 	 */
-	private function isRoute(array $config)
+	private function isRoute(array $config): bool
 	{
 		return
 			// The config array should at least have one entry
@@ -253,7 +260,7 @@ class Router
 	 * @throws HTTPException\MethodNotAllowedException    If a rule matched but the method didn't
 	 * @throws HTTPException\NotFoundException            If no rule matched
 	 */
-	private function getModuleClass()
+	private function getModuleClass(): string
 	{
 		$cmd = $this->args->getCommand();
 		$cmd = '/' . ltrim($cmd, '/');

src/BaseCollection.php

@@ -70,9 +70,11 @@ class BaseCollection extends \ArrayIterator
 	}
 
 	/**
-	 * @return int
+	 * Getter for total count
+	 *
+	 * @return int Total count
 	 */
-	public function getTotalCount()
+	public function getTotalCount(): int
 	{
 		return $this->totalCount;
 	}
@@ -85,7 +87,7 @@ class BaseCollection extends \ArrayIterator
 	 * @return array
 	 * @see array_column()
 	 */
-	public function column($column, $index_key = null)
+	public function column(string $column, $index_key = null): array
 	{
 		return array_column($this->getArrayCopy(true), $column, $index_key);
 	}
@@ -97,7 +99,7 @@ class BaseCollection extends \ArrayIterator
 	 * @return BaseCollection
 	 * @see array_map()
 	 */
-	public function map(callable $callback)
+	public function map(callable $callback): BaseCollection
 	{
 		return new static(array_map($callback, $this->getArrayCopy()), $this->getTotalCount());
 	}
@@ -110,7 +112,7 @@ class BaseCollection extends \ArrayIterator
 	 * @return BaseCollection
 	 * @see array_filter()
 	 */
-	public function filter(callable $callback = null, int $flag = 0)
+	public function filter(callable $callback = null, int $flag = 0): BaseCollection
 	{
 		return new static(array_filter($this->getArrayCopy(), $callback, $flag));
 	}

src/BaseEntity.php

@@ -55,14 +55,14 @@ abstract class BaseEntity extends BaseDataTransferObject
 	}
 
 	/**
-	 * @param $name
+	 * @param mixed $name
 	 * @return bool
 	 * @throws HTTPException\InternalServerErrorException
 	 */
-	public function __isset($name)
+	public function __isset($name): bool
 	{
 		if (!property_exists($this, $name)) {
-			throw new HTTPException\InternalServerErrorException('Unknown property ' . $name . ' in Entity ' . static::class);
+			throw new HTTPException\InternalServerErrorException('Unknown property ' . $name . ' of type ' . gettype($name) . ' in Entity ' . static::class);
 		}
 
 		return !empty($this->$name);

src/BaseModel.php

@@ -110,11 +110,11 @@ abstract class BaseModel extends BaseDataTransferObject
 	 * - $model->field (outside of class)
 	 * - $this->field (inside of class)
 	 *
-	 * @param $name
+	 * @param string $name Name of data to fetch
 	 * @return mixed
 	 * @throws HTTPException\InternalServerErrorException
 	 */
-	public function __get($name)
+	public function __get(string $name)
 	{
 		$this->checkValid();
 

src/BaseModule.php

@@ -331,7 +331,7 @@ abstract class BaseModule implements ICanHandleRequests
 	 *    Actually, important actions should not be triggered by Links / GET-Requests at all, but sometimes they still are,
 	 *    so this mechanism brings in some damage control (the attacker would be able to forge a request to a form of this type, but not to forms of other types).
 	 */
-	public static function getFormSecurityToken($typename = '')
+	public static function getFormSecurityToken(string $typename = '')
 	{
 		$user      = User::getById(DI::app()->getLoggedInUserId(), ['guid', 'prvkey']);
 		$timestamp = time();
@@ -340,7 +340,14 @@ abstract class BaseModule implements ICanHandleRequests
 		return $timestamp . '.' . $sec_hash;
 	}
 
-	public static function checkFormSecurityToken($typename = '', $formname = 'form_security_token')
+	/**
+	 * Checks if form's security (CSRF) token is valid.
+	 *
+	 * @param string $typename ???
+	 * @param string $formname Name of form/field (???)
+	 * @return bool Whether it is valid
+	 */
+	public static function checkFormSecurityToken(string $typename = '', string $formname = 'form_security_token'): bool
 	{
 		$hash = null;
 
@@ -372,12 +379,12 @@ abstract class BaseModule implements ICanHandleRequests
 		return ($sec_hash == $x[1]);
 	}
 
-	public static function getFormSecurityStandardErrorMessage()
+	public static function getFormSecurityStandardErrorMessage(): string
 	{
 		return DI::l10n()->t("The form security token was not correct. This probably happened because the form has been opened for too long \x28>3 hours\x29 before submitting it.") . EOL;
 	}
 
-	public static function checkFormSecurityTokenRedirectOnError($err_redirect, $typename = '', $formname = 'form_security_token')
+	public static function checkFormSecurityTokenRedirectOnError(string $err_redirect, string $typename = '', string $formname = 'form_security_token')
 	{
 		if (!self::checkFormSecurityToken($typename, $formname)) {
 			Logger::notice('checkFormSecurityToken failed: user ' . DI::app()->getLoggedInUserNickname() . ' - form element ' . $typename);
@@ -387,7 +394,7 @@ abstract class BaseModule implements ICanHandleRequests
 		}
 	}
 
-	public static function checkFormSecurityTokenForbiddenOnError($typename = '', $formname = 'form_security_token')
+	public static function checkFormSecurityTokenForbiddenOnError(string $typename = '', string $formname = 'form_security_token')
 	{
 		if (!self::checkFormSecurityToken($typename, $formname)) {
 			Logger::notice('checkFormSecurityToken failed: user ' . DI::app()->getLoggedInUserNickname() . ' - form element ' . $typename);

src/Contact/Avatar.php

@@ -123,7 +123,7 @@ class Avatar
 		return $fields;
 	}
 
-	private static function getFilename(string $url)
+	private static function getFilename(string $url): string
 	{
 		$guid = Item::guidFromUri($url, parse_url($url, PHP_URL_HOST));
 

src/Content/BoundariesPager.php

@@ -49,7 +49,7 @@ class BoundariesPager extends Pager
 	 * @param string  $last_item_id  The id† of the last item in the displayed item list
 	 * @param integer $itemsPerPage  An optional number of items per page to override the default value
 	 */
-	public function __construct(L10n $l10n, $queryString, $first_item_id = null, $last_item_id = null, $itemsPerPage = 50)
+	public function __construct(L10n $l10n, string $queryString, string $first_item_id = null, string $last_item_id = null, int $itemsPerPage = 50)
 	{
 		parent::__construct($l10n, $queryString, $itemsPerPage);
 
@@ -102,7 +102,7 @@ class BoundariesPager extends Pager
 	 * @return string HTML string of the pager
 	 * @throws \Exception
 	 */
-	public function renderMinimal(int $itemCount)
+	public function renderMinimal(int $itemCount): string
 	{
 		$displayedItemCount = max(0, intval($itemCount));
 

src/Content/ContactSelector.php

@@ -41,7 +41,7 @@ class ContactSelector
 	 * @param boolean $disabled optional, default false
 	 * @return string
 	 */
-	public static function pollInterval($current, $disabled = false)
+	public static function pollInterval(string $current, bool $disabled = false): string
 	{
 		$dis = (($disabled) ? ' disabled="disabled" ' : '');
 		$o = '';
@@ -84,7 +84,7 @@ class ContactSelector
 	 * @return string Server URL
 	 * @throws \Exception
 	 */
-	private static function getServerURLForProfile($profile)
+	private static function getServerURLForProfile(string $profile): string
 	{
 		if (!empty(self::$server_url[$profile])) {
 			return self::$server_url[$profile];
@@ -111,13 +111,16 @@ class ContactSelector
 	}
 
 	/**
+	 * Determines network name
+	 *
 	 * @param string $network  network of the contact
 	 * @param string $profile  optional, default empty
 	 * @param string $protocol (Optional) Protocol that is used for the transmission
+	 * @param int $gsid Server id
 	 * @return string
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function networkToName($network, $profile = '', $protocol = '', $gsid = 0)
+	public static function networkToName(string $network, string $profile = '', string $protocol = '', int $gsid = null): string
 	{
 		$nets = [
 			Protocol::DFRN      =>   DI::l10n()->t('DFRN'),
@@ -179,12 +182,15 @@ class ContactSelector
 	}
 
 	/**
+	 * Determines network's icon name
+	 *
 	 * @param string $network network
 	 * @param string $profile optional, default empty
-	 * @return string
+	 * @param int $gsid Server id
+	 * @return string Name for network icon
 	 * @throws \Exception
 	 */
-	public static function networkToIcon($network, $profile = "", $gsid = 0)
+	public static function networkToIcon(string $network, string $profile = "", int $gsid = null): string
 	{
 		$nets = [
 			Protocol::DFRN      =>   'friendica',

src/Content/Conversation.php

@@ -189,7 +189,7 @@ class Conversation
 	 * @return string formatted text
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public function formatActivity(array $links, $verb, $id)
+	public function formatActivity(array $links, string $verb, int $id): string
 	{
 		$this->profiler->startRecording('rendering');
 		$o        = '';
@@ -275,7 +275,7 @@ class Conversation
 		return $o;
 	}
 
-	public function statusEditor(array $x = [], $notes_cid = 0, $popup = false)
+	public function statusEditor(array $x = [], int $notes_cid = 0, bool $popup = false): string
 	{
 		$user = User::getById($this->app->getLoggedInUserId(), ['uid', 'nickname', 'allow_location', 'default-location']);
 		if (empty($user['uid'])) {
@@ -414,8 +414,8 @@ class Conversation
 	 * figures out how to determine page owner and other contextual items
 	 * that are based on unique features of the calling module.
 	 * @param array  $items
-	 * @param        $mode
+	 * @param string $mode
-	 * @param        $update
+	 * @param        $update @TODO Which type?
 	 * @param bool   $preview
 	 * @param string $order
 	 * @param int    $uid
@@ -423,7 +423,7 @@ class Conversation
 	 * @throws ImagickException
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public function create(array $items, $mode, $update, $preview = false, $order = 'commented', $uid = 0)
+	public function create(array $items, string $mode, $update, bool $preview = false, string $order = 'commented', int $uid = 0): string
 	{
 		$this->profiler->startRecording('rendering');
 
@@ -784,7 +784,7 @@ class Conversation
 		return $o;
 	}
 
-	private function getBlocklist()
+	private function getBlocklist(): array
 	{
 		if (!local_user()) {
 			return [];
@@ -816,7 +816,7 @@ class Conversation
 	 *
 	 * @return array items with parents and comments
 	 */
-	private function addRowInformation(array $row, array $activity, array $thr_parent)
+	private function addRowInformation(array $row, array $activity, array $thr_parent): array
 	{
 		$this->profiler->startRecording('rendering');
 
@@ -911,7 +911,7 @@ class Conversation
 	 * @return array items with parents and comments
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	private function addChildren(array $parents, bool $block_authors, string $order, int $uid, string $mode)
+	private function addChildren(array $parents, bool $block_authors, string $order, int $uid, string $mode): array
 	{
 		$this->profiler->startRecording('rendering');
 		if (count($parents) > 1) {
@@ -1005,7 +1005,7 @@ class Conversation
 	 * @param bool  $recursive
 	 * @return array
 	 */
-	private function getItemChildren(array &$item_list, array $parent, $recursive = true)
+	private function getItemChildren(array &$item_list, array $parent, bool $recursive = true): array
 	{
 		$this->profiler->startRecording('rendering');
 		$children = [];
@@ -1040,7 +1040,7 @@ class Conversation
 	 * @param array $items
 	 * @return array
 	 */
-	private function sortItemChildren(array $items)
+	private function sortItemChildren(array $items): array
 	{
 		$this->profiler->startRecording('rendering');
 		$result = $items;
@@ -1086,7 +1086,7 @@ class Conversation
 	 * @param array $parent A tree-like array of items
 	 * @return array
 	 */
-	private function smartFlattenConversation(array $parent)
+	private function smartFlattenConversation(array $parent): array
 	{
 		$this->profiler->startRecording('rendering');
 		if (!isset($parent['children']) || count($parent['children']) == 0) {
@@ -1142,7 +1142,7 @@ class Conversation
 	 * @return array
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	private function convSort(array $item_list, $order)
+	private function convSort(array $item_list, string $order): array
 	{
 		$this->profiler->startRecording('rendering');
 		$parents = [];
@@ -1222,7 +1222,7 @@ class Conversation
 	 * @param array $b
 	 * @return int
 	 */
-	private function sortThrFeaturedReceived(array $a, array $b)
+	private function sortThrFeaturedReceived(array $a, array $b): int
 	{
 		if ($b['featured'] && !$a['featured']) {
 			return 1;
@@ -1240,7 +1240,7 @@ class Conversation
 	 * @param array $b
 	 * @return int
 	 */
-	private function sortThrFeaturedCommented(array $a, array $b)
+	private function sortThrFeaturedCommented(array $a, array $b): int
 	{
 		if ($b['featured'] && !$a['featured']) {
 			return 1;
@@ -1258,7 +1258,7 @@ class Conversation
 	 * @param array $b
 	 * @return int
 	 */
-	private function sortThrReceived(array $a, array $b)
+	private function sortThrReceived(array $a, array $b): int
 	{
 		return strcmp($b['received'], $a['received']);
 	}
@@ -1270,7 +1270,7 @@ class Conversation
 	 * @param array $b
 	 * @return int
 	 */
-	private function sortThrReceivedRev(array $a, array $b)
+	private function sortThrReceivedRev(array $a, array $b): int
 	{
 		return strcmp($a['received'], $b['received']);
 	}
@@ -1282,7 +1282,7 @@ class Conversation
 	 * @param array $b
 	 * @return int
 	 */
-	private function sortThrCommented(array $a, array $b)
+	private function sortThrCommented(array $a, array $b): int
 	{
 		return strcmp($b['commented'], $a['commented']);
 	}
@@ -1294,7 +1294,7 @@ class Conversation
 	 * @param array $b
 	 * @return int
 	 */
-	private function sortThrCreated(array $a, array $b)
+	private function sortThrCreated(array $a, array $b): int
 	{
 		return strcmp($b['created'], $a['created']);
 	}

src/Content/Widget.php

@@ -45,7 +45,7 @@ class Widget
 	 * @return string
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function follow($value = "")
+	public static function follow(string $value = ''): string
 	{
 		return Renderer::replaceMacros(Renderer::getMarkupTemplate('widget/follow.tpl'), array(
 			'$connect' => DI::l10n()->t('Add New Contact'),
@@ -58,8 +58,10 @@ class Widget
 
 	/**
 	 * Return Find People widget
+	 *
+	 * @return string HTML code respresenting "People Widget"
 	 */
-	public static function findPeople()
+	public static function findPeople(): string
 	{
 		$global_dir = Search::getGlobalDirectory();
 
@@ -97,7 +99,7 @@ class Widget
 	 *
 	 * @return array Unsupported networks
 	 */
-	public static function unavailableNetworks()
+	public static function unavailableNetworks(): array
 	{
 		// Always hide content from these networks
 		$networks = [Protocol::PHANTOM, Protocol::FACEBOOK, Protocol::APPNET, Protocol::ZOT];
@@ -154,7 +156,7 @@ class Widget
 	 * @return string
 	 * @throws \Exception
 	 */
-	private static function filter($type, $title, $desc, $all, $baseUrl, array $options, $selected = null)
+	private static function filter(string $type, string $title, string $desc, string $all, string $baseUrl, array $options, string $selected = null): string
 	{
 		$queryString = parse_url($baseUrl, PHP_URL_QUERY);
 		$queryArray = [];
@@ -191,7 +193,7 @@ class Widget
 	 * @return string
 	 * @throws \Exception
 	 */
-	public static function groups($baseurl, $selected = '')
+	public static function groups(string $baseurl, string $selected = ''): string
 	{
 		if (!local_user()) {
 			return '';

src/Core/Worker.php

@@ -60,7 +60,7 @@ class Worker
 	 * @return void
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function processQueue($run_cron, Process $process)
+	public static function processQueue(bool $run_cron, Process $process)
 	{
 		self::$up_start = microtime(true);
 
@@ -169,7 +169,7 @@ class Worker
 	 *
 	 * @return boolean
 	 */
-	public static function isReady()
+	public static function isReady(): bool
 	{
 		// Count active workers and compare them with a maximum value that depends on the load
 		if (self::tooMuchWorkers()) {
@@ -204,7 +204,7 @@ class Worker
 	 * @return boolean Returns "true" if tasks are existing
 	 * @throws \Exception
 	 */
-	public static function entriesExists()
+	public static function entriesExists(): bool
 	{
 		$stamp = (float)microtime(true);
 		$exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
@@ -218,7 +218,7 @@ class Worker
 	 * @return integer Number of deferred entries in the worker queue
 	 * @throws \Exception
 	 */
-	private static function deferredEntries()
+	private static function deferredEntries(): int
 	{
 		$stamp = (float)microtime(true);
 		$count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `retrial` > ?", 0]);
@@ -233,7 +233,7 @@ class Worker
 	 * @return integer Number of non executed entries in the worker queue
 	 * @throws \Exception
 	 */
-	private static function totalEntries()
+	private static function totalEntries(): int
 	{
 		$stamp = (float)microtime(true);
 		$count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
@@ -248,7 +248,7 @@ class Worker
 	 * @return integer Number of active worker processes
 	 * @throws \Exception
 	 */
-	private static function highestPriority()
+	private static function highestPriority(): int
 	{
 		$stamp = (float)microtime(true);
 		$condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
@@ -269,7 +269,7 @@ class Worker
 	 * @return integer Is there a process running with that priority?
 	 * @throws \Exception
 	 */
-	private static function processWithPriorityActive($priority)
+	private static function processWithPriorityActive(int $priority): int
 	{
 		$condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 		return DBA::exists('workerqueue', $condition);
@@ -281,7 +281,7 @@ class Worker
 	 * @param mixed $file
 	 * @return bool
 	 */
-	private static function validateInclude(&$file)
+	private static function validateInclude(&$file): bool
 	{
 		$orig_file = $file;
 
@@ -321,7 +321,7 @@ class Worker
 	 * @return boolean "true" if further processing should be stopped
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function execute($queue)
+	public static function execute(array $queue): bool
 	{
 		$mypid = getmypid();
 
@@ -454,7 +454,7 @@ class Worker
 	 * @return void
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	private static function execFunction($queue, $funcname, $argv, $method_call)
+	private static function execFunction(array $queue, string $funcname, array $argv, bool $method_call)
 	{
 		$a = DI::app();
 
@@ -543,7 +543,7 @@ class Worker
 	 * @return bool Are more than 3/4 of the maximum connections used?
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	private static function maxConnectionsReached()
+	private static function maxConnectionsReached(): bool
 	{
 		// Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 		$max = DI::config()->get("system", "max_connections");
@@ -627,7 +627,7 @@ class Worker
 	 * @return bool Are there too much workers running?
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	private static function tooMuchWorkers()
+	private static function tooMuchWorkers(): bool
 	{
 		$queues = DI::config()->get("system", "worker_queues", 10);
 
@@ -751,7 +751,7 @@ class Worker
 	 * @return integer Number of active worker processes
 	 * @throws \Exception
 	 */
-	private static function activeWorkers()
+	private static function activeWorkers(): int
 	{
 		$stamp = (float)microtime(true);
 		$count = DI::process()->countCommand('Worker.php');
@@ -766,7 +766,7 @@ class Worker
 	 * @return array List of worker process ids
 	 * @throws \Exception
 	 */
-	private static function getWorkerPIDList()
+	private static function getWorkerPIDList(): array
 	{
 		$ids = [];
 		$stamp = (float)microtime(true);
@@ -787,7 +787,7 @@ class Worker
 	/**
 	 * Returns waiting jobs for the current process id
 	 *
-	 * @return array waiting workerqueue jobs
+	 * @return array|bool waiting workerqueue jobs or FALSE on failture
 	 * @throws \Exception
 	 */
 	private static function getWaitingJobForPID()
@@ -809,7 +809,7 @@ class Worker
 	 * @return array array with next jobs
 	 * @throws \Exception
 	 */
-	private static function nextProcess(int $limit)
+	private static function nextProcess(int $limit): array
 	{
 		$priority = self::nextPriority();
 		if (empty($priority)) {
@@ -844,7 +844,7 @@ class Worker
 	/**
 	 * Returns the priority of the next workerqueue job
 	 *
-	 * @return string priority
+	 * @return string|bool priority or FALSE on failure
 	 * @throws \Exception
 	 */
 	private static function nextPriority()
@@ -915,7 +915,7 @@ class Worker
 	/**
 	 * Find and claim the next worker process for us
 	 *
-	 * @return boolean Have we found something?
+	 * @return void
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	private static function findWorkerProcesses()
@@ -993,7 +993,7 @@ class Worker
 	 * @return array worker processes
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function workerProcess()
+	public static function workerProcess(): array
 	{
 		// There can already be jobs for us in the queue.
 		$waiting = self::getWaitingJobForPID();
@@ -1003,7 +1003,7 @@ class Worker
 
 		$stamp = (float)microtime(true);
 		if (!DI::lock()->acquire(self::LOCK_PROCESS)) {
-			return false;
+			return [];
 		}
 		self::$lock_duration += (microtime(true) - $stamp);
 
@@ -1011,7 +1011,9 @@ class Worker
 
 		DI::lock()->release(self::LOCK_PROCESS);
 
-		return self::getWaitingJobForPID();
+		// Prevents "Return value of Friendica\Core\Worker::workerProcess() must be of the type array, bool returned"
+		$process = self::getWaitingJobForPID();
+		return (is_array($process) ? $process : []);
 	}
 
 	/**
@@ -1097,7 +1099,7 @@ class Worker
 	 * @return void
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function spawnWorker($do_cron = false)
+	public static function spawnWorker(bool $do_cron = false)
 	{
 		if (Worker\Daemon::isMode() && DI::config()->get('system', 'worker_fork')) {
 			self::forkProcess($do_cron);
@@ -1231,7 +1233,7 @@ class Worker
 		return $added;
 	}
 
-	public static function countWorkersByCommand(string $command)
+	public static function countWorkersByCommand(string $command): int
 	{
 		return DBA::count('workerqueue', ['done' => false, 'pid' => 0, 'command' => $command]);
 	}
@@ -1244,7 +1246,7 @@ class Worker
 	 * @param integer $max_level maximum retrial level
 	 * @return integer the next retrial level value
 	 */
-	private static function getNextRetrial($queue, $max_level)
+	private static function getNextRetrial(array $queue, int $max_level): int
 	{
 		$created = strtotime($queue['created']);
 		$retrial_time = time() - $created;
@@ -1314,9 +1316,10 @@ class Worker
 	/**
 	 * Check if the system is inside the defined maintenance window
 	 *
+	 * @param bool $check_last_execution Whether check last execution
 	 * @return boolean
 	 */
-	public static function isInMaintenanceWindow(bool $check_last_execution = false)
+	public static function isInMaintenanceWindow(bool $check_last_execution = false): bool
 	{
 		// Calculate the seconds of the start end end of the maintenance window
 		$start = strtotime(DI::config()->get('system', 'maintenance_start')) % 86400;

src/Database/DBA.php

@@ -427,7 +427,7 @@ class DBA
 	 * @return boolean was the update successfull?
 	 * @throws \Exception
 	 */
-	public static function update($table, $fields, $condition, $old_fields = [], $params = [])
+	public static function update($table, array $fields, array $condition, $old_fields = [], array $params = [])
 	{
 		return DI::dba()->update($table, $fields, $condition, $old_fields, $params);
 	}
@@ -443,7 +443,7 @@ class DBA
 	 * @throws \Exception
 	 * @see   self::select
 	 */
-	public static function selectFirst($table, array $fields = [], array $condition = [], $params = [])
+	public static function selectFirst($table, array $fields = [], array $condition = [], array $params = [])
 	{
 		return DI::dba()->selectFirst($table, $fields, $condition, $params);
 	}
@@ -512,7 +512,7 @@ class DBA
 	 * $count = DBA::count($table, $condition);
 	 * @throws \Exception
 	 */
-	public static function count($table, array $condition = [], array $params = [])
+	public static function count($table, array $condition = [], array $params = []): int
 	{
 		return DI::dba()->count($table, $condition, $params);
 	}
@@ -771,7 +771,7 @@ class DBA
 	 *
 	 * @return array Data array
 	 */
-	public static function toArray($stmt, $do_close = true, int $count = 0)
+	public static function toArray($stmt, $do_close = true, int $count = 0): array
 	{
 		return DI::dba()->toArray($stmt, $do_close, $count);
 	}
@@ -783,7 +783,7 @@ class DBA
 	 * @param array  $fields
 	 * @return array casted fields
 	 */
-	public static function castFields(string $table, array $fields)
+	public static function castFields(string $table, array $fields): array
 	{
 		return DI::dba()->castFields($table, $fields);
 	}
@@ -793,7 +793,7 @@ class DBA
 	 *
 	 * @return string Error number (0 if no error)
 	 */
-	public static function errorNo()
+	public static function errorNo(): int
 	{
 		return DI::dba()->errorNo();
 	}
@@ -803,7 +803,7 @@ class DBA
 	 *
 	 * @return string Error message ('' if no error)
 	 */
-	public static function errorMessage()
+	public static function errorMessage(): string
 	{
 		return DI::dba()->errorMessage();
 	}
@@ -814,7 +814,7 @@ class DBA
 	 * @param object $stmt statement object
 	 * @return boolean was the close successful?
 	 */
-	public static function close($stmt)
+	public static function close($stmt): bool
 	{
 		return DI::dba()->close($stmt);
 	}
@@ -827,7 +827,7 @@ class DBA
 	 *      'amount' => Number of concurrent database processes
 	 * @throws \Exception
 	 */
-	public static function processlist()
+	public static function processlist(): array
 	{
 		return DI::dba()->processlist();
 	}

src/Database/Database.php

@@ -541,7 +541,7 @@ class Database
 					if (!$retval = $this->connection->query($this->replaceParameters($sql, $args))) {
 						$errorInfo     = $this->connection->errorInfo();
 						$this->error   = $errorInfo[2];
-						$this->errorno = $errorInfo[1];
+						$this->errorno = (int) $errorInfo[1];
 						$retval        = false;
 						$is_error      = true;
 						break;
@@ -554,7 +554,7 @@ class Database
 				if (!$stmt = $this->connection->prepare($sql)) {
 					$errorInfo     = $this->connection->errorInfo();
 					$this->error   = $errorInfo[2];
-					$this->errorno = $errorInfo[1];
+					$this->errorno = (int) $errorInfo[1];
 					$retval        = false;
 					$is_error      = true;
 					break;
@@ -574,7 +574,7 @@ class Database
 				if (!$stmt->execute()) {
 					$errorInfo     = $stmt->errorInfo();
 					$this->error   = $errorInfo[2];
-					$this->errorno = $errorInfo[1];
+					$this->errorno = (int) $errorInfo[1];
 					$retval        = false;
 					$is_error      = true;
 				} else {
@@ -709,7 +709,7 @@ class Database
 			}
 
 			$this->error   = $error;
-			$this->errorno = $errorno;
+			$this->errorno = (int) $errorno;
 		}
 
 		$this->profiler->stopRecording();
@@ -1541,7 +1541,7 @@ class Database
 	 *
 	 * @return array Data array
 	 */
-	public function toArray($stmt, $do_close = true, int $count = 0)
+	public function toArray($stmt, bool $do_close = true, int $count = 0): array
 	{
 		if (is_bool($stmt)) {
 			return [];
@@ -1632,7 +1632,7 @@ class Database
 	 *
 	 * @return string Error number (0 if no error)
 	 */
-	public function errorNo()
+	public function errorNo(): int
 	{
 		return $this->errorno;
 	}
@@ -1654,7 +1654,7 @@ class Database
 	 *
 	 * @return boolean was the close successful?
 	 */
-	public function close($stmt)
+	public function close($stmt): bool
 	{
 
 		$this->profiler->startRecording('database');
@@ -1696,7 +1696,7 @@ class Database
 	 *      'amount' => Number of concurrent database processes
 	 * @throws \Exception
 	 */
-	public function processlist()
+	public function processlist(): array
 	{
 		$ret  = $this->p("SHOW PROCESSLIST");
 		$data = $this->toArray($ret);

src/Factory/Api/Mastodon/Account.php

@@ -57,7 +57,7 @@ class Account extends BaseFactory
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws ImagickException|HTTPException\NotFoundException
 	 */
-	public function createFromContactId(int $contactId, $uid = 0): \Friendica\Object\Api\Mastodon\Account
+	public function createFromContactId(int $contactId, int $uid = 0): \Friendica\Object\Api\Mastodon\Account
 	{
 		$contact = Contact::getById($contactId, ['uri-id']);
 		if (empty($contact)) {
@@ -74,7 +74,7 @@ class Account extends BaseFactory
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws ImagickException|HTTPException\NotFoundException
 	 */
-	public function createFromUriId(int $contactUriId, $uid = 0): \Friendica\Object\Api\Mastodon\Account
+	public function createFromUriId(int $contactUriId, int $uid = 0): \Friendica\Object\Api\Mastodon\Account
 	{
 		$account = DBA::selectFirst('account-user-view', [], ['uri-id' => $contactUriId, 'uid' => [0, $uid]], ['order' => ['id' => true]]);
 		if (empty($account)) {

src/Factory/Api/Twitter/Status.php

@@ -70,6 +70,7 @@ class Status extends BaseFactory
 	/**
 	 * @param int $uriId Uri-ID of the item
 	 * @param int $uid   Item user
+	 * @param bool $include_entities Whether to include entities
 	 *
 	 * @return \Friendica\Object\Api\Twitter\Status
 	 * @throws HTTPException\InternalServerErrorException
@@ -90,12 +91,13 @@ class Status extends BaseFactory
 	/**
 	 * @param int $uriId Uri-ID of the item
 	 * @param int $uid   Item user
+	 * @param bool $include_entities Whether to include entities
 	 *
 	 * @return \Friendica\Object\Api\Twitter\Status
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws ImagickException|HTTPException\NotFoundException
 	 */
-	public function createFromUriId(int $uriId, $uid = 0, $include_entities = false): \Friendica\Object\Api\Twitter\Status
+	public function createFromUriId(int $uriId, int $uid = 0, bool $include_entities = false): \Friendica\Object\Api\Twitter\Status
 	{
 		$fields = ['parent-uri-id', 'uri-id', 'uid', 'author-id', 'author-link', 'author-network', 'owner-id', 'causer-id',
 			'starred', 'app', 'title', 'body', 'raw-body', 'created', 'network','post-reason', 'language', 'gravity',
@@ -110,6 +112,7 @@ class Status extends BaseFactory
 	/**
 	 * @param array $item item array
 	 * @param int   $uid  Item user
+	 * @param bool $include_entities Whether to include entities
 	 *
 	 * @return \Friendica\Object\Api\Twitter\Status
 	 * @throws HTTPException\InternalServerErrorException

src/Factory/Api/Twitter/User.php

@@ -51,7 +51,7 @@ class User extends BaseFactory
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public function createFromContactId(int $contactId, $uid = 0, $skip_status = true, $include_user_entities = true)
+	public function createFromContactId(int $contactId, int $uid = 0, bool $skip_status = true, bool $include_user_entities = true)
 	{
 		$cdata = Contact::getPublicAndUserContactID($contactId, $uid);
 		if (!empty($cdata)) {
@@ -78,7 +78,7 @@ class User extends BaseFactory
 		return new \Friendica\Object\Api\Twitter\User($publicContact, $apcontact, $userContact, $status, $include_user_entities);
 	}
 
-	public function createFromUserId(int $uid, $skip_status = true, $include_user_entities = true)
+	public function createFromUserId(int $uid, bool $skip_status = true, bool $include_user_entities = true)
 	{
 		return $this->createFromContactId(Contact::getPublicIdByUserId($uid), $uid, $skip_status, $include_user_entities);
 	}

src/LegacyModule.php

@@ -57,7 +57,7 @@ class LegacyModule extends BaseModule
 	 * @param string $file_path
 	 * @throws \Exception
 	 */
-	private function setModuleFile($file_path)
+	private function setModuleFile(string $file_path)
 	{
 		if (!is_readable($file_path)) {
 			throw new \Exception(DI::l10n()->t('Legacy module file not found: %s', $file_path));
@@ -87,7 +87,7 @@ class LegacyModule extends BaseModule
 	 * @return string
 	 * @throws \Exception
 	 */
-	private function runModuleFunction(string $function_suffix)
+	private function runModuleFunction(string $function_suffix): string
 	{
 		$function_name = $this->moduleName . '_' . $function_suffix;
 

src/Model/APContact.php

@@ -48,7 +48,7 @@ class APContact
 	 * @param string $addr Address
 	 * @return array webfinger data
 	 */
-	private static function fetchWebfingerData(string $addr)
+	private static function fetchWebfingerData(string $addr): array
 	{
 		$addr_parts = explode('@', $addr);
 		if (count($addr_parts) != 2) {
@@ -117,14 +117,14 @@ class APContact
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function getByURL($url, $update = null)
+	public static function getByURL(string $url, $update = null): array
 	{
 		if (empty($url) || Network::isUrlBlocked($url)) {
 			Logger::info('Domain is blocked', ['url' => $url]);
 			return [];
 		}
 
-		$fetched_contact = false;
+		$fetched_contact = [];
 
 		if (empty($update)) {
 			if (is_null($update)) {
@@ -220,14 +220,14 @@ class APContact
 		$apcontact['type'] = str_replace('as:', '', JsonLD::fetchElement($compacted, '@type'));
 		$apcontact['following'] = JsonLD::fetchElement($compacted, 'as:following', '@id');
 		$apcontact['followers'] = JsonLD::fetchElement($compacted, 'as:followers', '@id');
-		$apcontact['inbox'] = JsonLD::fetchElement($compacted, 'ldp:inbox', '@id');
+		$apcontact['inbox'] = (JsonLD::fetchElement($compacted, 'ldp:inbox', '@id') ?? '');
 		self::unarchiveInbox($apcontact['inbox'], false);
 
 		$apcontact['outbox'] = JsonLD::fetchElement($compacted, 'as:outbox', '@id');
 
 		$apcontact['sharedinbox'] = '';
 		if (!empty($compacted['as:endpoints'])) {
-			$apcontact['sharedinbox'] = JsonLD::fetchElement($compacted['as:endpoints'], 'as:sharedInbox', '@id');
+			$apcontact['sharedinbox'] = (JsonLD::fetchElement($compacted['as:endpoints'], 'as:sharedInbox', '@id') ?? '');
 			self::unarchiveInbox($apcontact['sharedinbox'], true);
 		}
 
@@ -527,7 +527,7 @@ class APContact
 	 * @param string  $url    inbox url
 	 * @param boolean $shared Shared Inbox
 	 */
-	private static function unarchiveInbox($url, $shared)
+	private static function unarchiveInbox(string $url, bool $shared)
 	{
 		if (empty($url)) {
 			return;

src/Model/Attach.php

@@ -59,7 +59,7 @@ class Attach
 	 * @param array $conditions Array of fields for conditions
 	 * @param array $params     Array of several parameters
 	 *
-	 * @return array
+	 * @return array|bool
 	 *
 	 * @throws \Exception
 	 * @see   \Friendica\Database\DBA::selectToArray
@@ -102,7 +102,7 @@ class Attach
 	 * @return boolean
 	 * @throws \Exception
 	 */
-	public static function exists(array $conditions)
+	public static function exists(array $conditions): bool
 	{
 		return DBA::exists('attach', $conditions);
 	}
@@ -117,7 +117,7 @@ class Attach
 	 * @throws \Exception
 	 * @see   \Friendica\Database\DBA::select
 	 */
-	public static function getById($id)
+	public static function getById(int $id)
 	{
 		return self::selectFirst([], ['id' => $id]);
 	}
@@ -132,7 +132,7 @@ class Attach
 	 * @throws \Exception
 	 * @see   \Friendica\Database\DBA::select
 	 */
-	public static function getByIdWithPermission($id)
+	public static function getByIdWithPermission(int $id)
 	{
 		$r = self::selectFirst(['uid'], ['id' => $id]);
 		if ($r === false) {
@@ -156,10 +156,10 @@ class Attach
 	 *
 	 * @param array $item Attachment data. Needs at least 'id', 'backend-class', 'backend-ref'
 	 *
-	 * @return string  file data
+	 * @return string|null file data or null on failure
 	 * @throws \Exception
 	 */
-	public static function getData($item)
+	public static function getData(array $item)
 	{
 		if (!empty($item['data'])) {
 			return $item['data'];
@@ -195,10 +195,10 @@ class Attach
 	 * @param string  $deny_cid  Permissions, denied contacts.optional, default = ''
 	 * @param string  $deny_gid  Permissions, denied greoup.optional, default = ''
 	 *
-	 * @return boolean/integer Row id on success, False on errors
+	 * @return boolean|integer Row id on success, False on errors
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function store($data, $uid, $filename, $filetype = '' , $filesize = null, $allow_cid = '', $allow_gid = '', $deny_cid = '', $deny_gid = '')
+	public static function store(string $data, int $uid, string $filename, string $filetype = '' , int $filesize = null, string $allow_cid = '', string $allow_gid = '', string $deny_cid = '', string $deny_gid = '')
 	{
 		if ($filetype === '') {
 			$filetype = Mimetype::getContentType($filename);
@@ -241,17 +241,17 @@ class Attach
 	/**
 	 * Store new file metadata in db and binary in default backend from existing file
 	 *
-	 * @param        $src
+	 * @param string $src Source file name
-	 * @param        $uid
+	 * @param int    $uid User id
-	 * @param string $filename
+	 * @param string $filename Optional file name
 	 * @param string $allow_cid
 	 * @param string $allow_gid
 	 * @param string $deny_cid
 	 * @param string $deny_gid
-	 * @return boolean True on success
+	 * @return boolean|int Insert id or false on failure
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function storeFile($src, $uid, $filename = '', $allow_cid = '', $allow_gid = '', $deny_cid = '', $deny_gid = '')
+	public static function storeFile(string $src, int $uid, string $filename = '', string $allow_cid = '', string $allow_gid = '', string $deny_cid = '', string $deny_gid = '')
 	{
 		if ($filename === '') {
 			$filename = basename($src);
@@ -276,7 +276,7 @@ class Attach
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @see   \Friendica\Database\DBA::update
 	 */
-	public static function update($fields, $conditions, Image $img = null, array $old_fields = [])
+	public static function update(array $fields, array $conditions, Image $img = null, array $old_fields = []): bool
 	{
 		if (!is_null($img)) {
 			// get items to update
@@ -311,7 +311,7 @@ class Attach
 	 * @throws \Exception
 	 * @see   \Friendica\Database\DBA::delete
 	 */
-	public static function delete(array $conditions, array $options = [])
+	public static function delete(array $conditions, array $options = []): bool
 	{
 		// get items to delete data info
 		$items = self::selectToArray(['backend-class','backend-ref'], $conditions);

src/Model/Contact.php

@@ -119,7 +119,7 @@ class Contact
 	 * @return array
 	 * @throws \Exception
 	 */
-	public static function selectToArray(array $fields = [], array $condition = [], array $params = [])
+	public static function selectToArray(array $fields = [], array $condition = [], array $params = []): array
 	{
 		return DBA::selectToArray('contact', $fields, $condition, $params);
 	}
@@ -128,7 +128,7 @@ class Contact
 	 * @param array $fields    Array of selected fields, empty for all
 	 * @param array $condition Array of fields for condition
 	 * @param array $params    Array of several parameters
-	 * @return array
+	 * @return array|bool
 	 * @throws \Exception
 	 */
 	public static function selectFirst(array $fields = [], array $condition = [], array $params = [])
@@ -148,7 +148,7 @@ class Contact
 	 * @return int  id of the created contact
 	 * @throws \Exception
 	 */
-	public static function insert(array $fields, int $duplicate_mode = Database::INSERT_DEFAULT)
+	public static function insert(array $fields, int $duplicate_mode = Database::INSERT_DEFAULT): int
 	{
 		if (!empty($fields['baseurl']) && empty($fields['gsid'])) {
 			$fields['gsid'] = GServer::getID($fields['baseurl'], true);
@@ -187,6 +187,7 @@ class Contact
 	 *
 	 * @return boolean was the update successfull?
 	 * @throws \Exception
+	 * @todo Let's get rid of boolean type of $old_fields
 	 */
 	public static function update(array $fields, array $condition, $old_fields = [])
 	{
@@ -204,7 +205,7 @@ class Contact
 	 * @return array|boolean Contact record if it exists, false otherwise
 	 * @throws \Exception
 	 */
-	public static function getById($id, $fields = [])
+	public static function getById(int $id, array $fields = [])
 	{
 		return DBA::selectFirst('contact', $fields, ['id' => $id]);
 	}
@@ -217,7 +218,7 @@ class Contact
 	 * @return array|boolean Contact record if it exists, false otherwise
 	 * @throws \Exception
 	 */
-	public static function getByUriId($uri_id, $fields = [])
+	public static function getByUriId(int $uri_id, array $fields = [])
 	{
 		return DBA::selectFirst('contact', $fields, ['uri-id' => $uri_id], ['order' => ['uid']]);
 	}
@@ -231,7 +232,7 @@ class Contact
 	 * @param integer $uid    User ID of the contact
 	 * @return array contact array
 	 */
-	public static function getByURL(string $url, $update = null, array $fields = [], int $uid = 0)
+	public static function getByURL(string $url, $update = null, array $fields = [], int $uid = 0): array
 	{
 		if ($update || is_null($update)) {
 			$cid = self::getIdForURL($url, $uid, $update);
@@ -302,7 +303,7 @@ class Contact
 	 * @param array   $fields Field list
 	 * @return array contact array
 	 */
-	public static function getByURLForUser(string $url, int $uid = 0, $update = false, array $fields = [])
+	public static function getByURLForUser(string $url, int $uid = 0, $update = false, array $fields = []): array
 	{
 		if ($uid != 0) {
 			$contact = self::getByURL($url, $update, $fields, $uid);
@@ -333,7 +334,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function isFollower($cid, $uid)
+	public static function isFollower(int $cid, int $uid): bool
 	{
 		if (Contact\User::isBlocked($cid, $uid)) {
 			return false;
@@ -358,7 +359,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function isFollowerByURL($url, $uid)
+	public static function isFollowerByURL(string $url, uid $uid): bool
 	{
 		$cid = self::getIdForURL($url, $uid);
 
@@ -370,16 +371,16 @@ class Contact
 	}
 
 	/**
-	 * Tests if the given user follow the given contact
+	 * Tests if the given user shares with the given contact
 	 *
 	 * @param int $cid Either public contact id or user's contact id
 	 * @param int $uid User ID
 	 *
-	 * @return boolean is the contact url being followed?
+	 * @return boolean is the contact sharing with given user?
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function isSharing($cid, $uid)
+	public static function isSharing(int $cid, int $uid): bool
 	{
 		if (Contact\User::isBlocked($cid, $uid)) {
 			return false;
@@ -404,7 +405,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function isSharingByURL($url, $uid)
+	public static function isSharingByURL(string $url, int $uid): bool
 	{
 		$cid = self::getIdForURL($url, $uid);
 
@@ -425,7 +426,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function getBasepath($url, $dont_update = false)
+	public static function getBasepath(string $url, bool $dont_update = false): string
 	{
 		$contact = DBA::selectFirst('contact', ['id', 'baseurl'], ['uid' => 0, 'nurl' => Strings::normaliseLink($url)]);
 		if (!DBA::isResult($contact)) {
@@ -459,7 +460,7 @@ class Contact
 	 *
 	 * @return boolean Is it the same server?
 	 */
-	public static function isLocal($url)
+	public static function isLocal(string $url): bool
 	{
 		if (!parse_url($url, PHP_URL_SCHEME)) {
 			$addr_parts = explode('@', $url);
@@ -476,7 +477,7 @@ class Contact
 	 *
 	 * @return boolean Is it the same server?
 	 */
-	public static function isLocalById(int $cid)
+	public static function isLocalById(int $cid): bool
 	{
 		$contact = DBA::selectFirst('contact', ['url', 'baseurl'], ['id' => $cid]);
 		if (!DBA::isResult($contact)) {
@@ -500,7 +501,7 @@ class Contact
 	 * @return integer|boolean Public contact id for given user id
 	 * @throws \Exception
 	 */
-	public static function getPublicIdByUserId($uid)
+	public static function getPublicIdByUserId(int $uid)
 	{
 		$self = DBA::selectFirst('contact', ['url'], ['self' => true, 'uid' => $uid]);
 		if (!DBA::isResult($self)) {
@@ -519,7 +520,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function getPublicAndUserContactID($cid, $uid)
+	public static function getPublicAndUserContactID(int $cid, int $uid): array
 	{
 		// We have to use the legacy function as long as the post update hasn't finished
 		if (DI::config()->get('system', 'post_update_version') < 1427) {
@@ -560,7 +561,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	private static function legacyGetPublicAndUserContactID($cid, $uid)
+	private static function legacyGetPublicAndUserContactID(int $cid, int $uid): array
 	{
 		if (empty($uid) || empty($cid)) {
 			return [];
@@ -1526,7 +1527,7 @@ class Contact
 	 * @param int $type type of contact or account
 	 * @return string
 	 */
-	public static function getAccountType(int $type)
+	public static function getAccountType(int $type): string
 	{
 		switch ($type) {
 			case self::TYPE_ORGANISATION:
@@ -1552,11 +1553,11 @@ class Contact
 	/**
 	 * Blocks a contact
 	 *
-	 * @param int $cid
+	 * @param int $cid Contact id to block
-	 * @return bool
+	 * @param string $reason Block reason
-	 * @throws \Exception
+	 * @return bool Whether it was successful
 	 */
-	public static function block($cid, $reason = null)
+	public static function block(int $cid, string $reason = null): bool
 	{
 		$return = self::update(['blocked' => true, 'block_reason' => $reason], ['id' => $cid]);
 
@@ -1566,11 +1567,10 @@ class Contact
 	/**
 	 * Unblocks a contact
 	 *
-	 * @param int $cid
+	 * @param int $cid Contact id to unblock
-	 * @return bool
+	 * @return bool Whether it was successfull
-	 * @throws \Exception
 	 */
-	public static function unblock($cid)
+	public static function unblock(int $cid): bool
 	{
 		$return = self::update(['blocked' => false, 'block_reason' => null], ['id' => $cid]);
 
@@ -1580,7 +1580,7 @@ class Contact
 	/**
 	 * Ensure that cached avatar exist
 	 *
-	 * @param integer $cid
+	 * @param integer $cid Contact id
 	 */
 	public static function checkAvatarCache(int $cid)
 	{
@@ -1620,7 +1620,7 @@ class Contact
 	 * @param bool  $no_update Don't perfom an update if no cached avatar was found
 	 * @return string photo path
 	 */
-	private static function getAvatarPath(array $contact, string $size, $no_update = false)
+	private static function getAvatarPath(array $contact, string $size, bool $no_update = false): string
 	{
 		$contact = self::checkAvatarCacheByArray($contact, $no_update);
 
@@ -1654,7 +1654,7 @@ class Contact
 	 * @param bool   $no_update Don't perfom an update if no cached avatar was found
 	 * @return string photo path
 	 */
-	public static function getPhoto(array $contact, bool $no_update = false)
+	public static function getPhoto(array $contact, bool $no_update = false): string
 	{
 		return self::getAvatarPath($contact, Proxy::SIZE_SMALL, $no_update);
 	}
@@ -1666,7 +1666,7 @@ class Contact
 	 * @param bool   $no_update Don't perfom an update if no cached avatar was found
 	 * @return string photo path
 	 */
-	public static function getThumb(array $contact, bool $no_update = false)
+	public static function getThumb(array $contact, bool $no_update = false): string
 	{
 		return self::getAvatarPath($contact, Proxy::SIZE_THUMB, $no_update);
 	}
@@ -1678,7 +1678,7 @@ class Contact
 	 * @param bool   $no_update Don't perfom an update if no cached avatar was found
 	 * @return string photo path
 	 */
-	public static function getMicro(array $contact, bool $no_update = false)
+	public static function getMicro(array $contact, bool $no_update = false): string
 	{
 		return self::getAvatarPath($contact, Proxy::SIZE_MICRO, $no_update);
 	}
@@ -1690,7 +1690,7 @@ class Contact
 	 * @param bool  $no_update Don't perfom an update if no cached avatar was found
 	 * @return array contact array with avatar cache fields
 	 */
-	private static function checkAvatarCacheByArray(array $contact, bool $no_update = false)
+	private static function checkAvatarCacheByArray(array $contact, bool $no_update = false): array
 	{
 		$update = false;
 		$contact_fields = [];
@@ -1796,7 +1796,7 @@ class Contact
 	 * @param string $size    Size of the avatar picture
 	 * @return string avatar URL
 	 */
-	public static function getDefaultAvatar(array $contact, string $size)
+	public static function getDefaultAvatar(array $contact, string $size): string
 	{
 		switch ($size) {
 			case Proxy::SIZE_MICRO:
@@ -2614,7 +2614,7 @@ class Contact
 	 * @throws HTTPException\NotFoundException
 	 * @throws \ImagickException
 	 */
-	public static function createFromProbeForUser(int $uid, $url, $network = '')
+	public static function createFromProbeForUser(int $uid, string $url, string $network = ''): array
 	{
 		$result = ['cid' => -1, 'success' => false, 'message' => ''];
 
@@ -2803,7 +2803,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function addRelationship(array $importer, array $contact, array $datarray, $sharing = false, $note = '')
+	public static function addRelationship(array $importer, array $contact, array $datarray, bool $sharing = false, string $note = '')
 	{
 		// Should always be set
 		if (empty($datarray['author-id'])) {
@@ -3030,7 +3030,7 @@ class Contact
 	 * @return array
 	 * @throws \Exception
 	 */
-	public static function pruneUnavailable(array $contact_ids)
+	public static function pruneUnavailable(array $contact_ids): array
 	{
 		if (empty($contact_ids)) {
 			return [];
@@ -3058,7 +3058,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function magicLink($contact_url, $url = '')
+	public static function magicLink(string $contact_url, string $url = ''): string
 	{
 		if (!Session::isAuthenticated()) {
 			return $url ?: $contact_url; // Equivalent to: ($url != '') ? $url : $contact_url;
@@ -3085,7 +3085,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function magicLinkById($cid, $url = '')
+	public static function magicLinkById(int $cid, string $url = ''): string
 	{
 		$contact = DBA::selectFirst('contact', ['id', 'network', 'url', 'uid'], ['id' => $cid]);
 
@@ -3102,7 +3102,7 @@ class Contact
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function magicLinkByContact($contact, $url = '')
+	public static function magicLinkByContact(array $contact, string $url = ''): string
 	{
 		$destination = $url ?: $contact['url']; // Equivalent to ($url != '') ? $url : $contact['url'];
 
@@ -3143,7 +3143,7 @@ class Contact
 	 *
 	 * @return boolean "true" if it is a forum
 	 */
-	public static function isForum($contactid)
+	public static function isForum(int $contactid): bool
 	{
 		$fields = ['contact-type'];
 		$condition = ['id' => $contactid];
@@ -3162,7 +3162,7 @@ class Contact
 	 * @param array $contact
 	 * @return bool
 	 */
-	public static function canReceivePrivateMessages(array $contact)
+	public static function canReceivePrivateMessages(array $contact): bool
 	{
 		$protocol = $contact['network'] ?? $contact['protocol'] ?? Protocol::PHANTOM;
 		$self = $contact['self'] ?? false;
@@ -3180,7 +3180,7 @@ class Contact
 	 * @return array with search results
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function searchByName(string $search, string $mode = '', int $uid = 0)
+	public static function searchByName(string $search, string $mode = '', int $uid = 0): array
 	{
 		if (empty($search)) {
 			return [];
@@ -3223,7 +3223,7 @@ class Contact
 	 * @param array $urls
 	 * @return array result "count", "added" and "updated"
 	 */
-	public static function addByUrls(array $urls)
+	public static function addByUrls(array $urls): array
 	{
 		$added = 0;
 		$updated = 0;
@@ -3256,7 +3256,7 @@ class Contact
 	 * @return array The profile array
 	 * @throws Exception
 	 */
-	public static function getRandomContact()
+	public static function getRandomContact(): array
 	{
 		$contact = DBA::selectFirst('contact', ['id', 'network', 'url', 'uid'], [
 			"`uid` = ? AND `network` = ? AND NOT `failed` AND `last-item` > ?",

src/Model/Conversation.php

@@ -62,7 +62,7 @@ class Conversation
 	 */
 	const RELAY   = 3;
 
-	public static function getByItemUri($item_uri)
+	public static function getByItemUri(string $item_uri)
 	{
 		return DBA::selectFirst('conversation', [], ['item-uri' => $item_uri]);
 	}
@@ -74,7 +74,7 @@ class Conversation
 	 * @return array Item array with removed conversation data
 	 * @throws \Exception
 	 */
-	public static function insert(array $arr)
+	public static function insert(array $arr): array
 	{
 		if (in_array(($arr['network'] ?? '') ?: Protocol::PHANTOM,
 			[Protocol::ACTIVITYPUB, Protocol::DFRN, Protocol::DIASPORA, Protocol::OSTATUS, Protocol::TWITTER]) && !empty($arr['uri'])) {

src/Model/Event.php

@@ -41,7 +41,7 @@ use Friendica\Util\XML;
 class Event
 {
 
-	public static function getHTML(array $event, $simple = false, $uriid = 0)
+	public static function getHTML(array $event, bool $simple = false, int $uriid = 0): string
 	{
 		if (empty($event)) {
 			return '';
@@ -127,7 +127,7 @@ class Event
 	 * @param array $event Array which contains the event data.
 	 * @return string The event as a bbcode formatted string.
 	 */
-	private static function getBBCode(array $event)
+	private static function getBBCode(array $event): string
 	{
 		$o = '';
 
@@ -157,11 +157,10 @@ class Event
 	/**
 	 * Extract bbcode formatted event data from a string.
 	 *
-	 * @params: string $s The string which should be parsed for event data.
+	 * @param string $text The string which should be parsed for event data.
-	 * @param $text
 	 * @return array The array with the event information.
 	 */
-	public static function fromBBCode($text)
+	public static function fromBBCode(string $text): array
 	{
 		$ev = [];
 
@@ -195,13 +194,13 @@ class Event
 		return $ev;
 	}
 
-	public static function sortByDate($event_list)
+	public static function sortByDate(array $event_list): array
 	{
 		usort($event_list, ['self', 'compareDatesCallback']);
 		return $event_list;
 	}
 
-	private static function compareDatesCallback($event_a, $event_b)
+	private static function compareDatesCallback(array $event_a, array $event_b)
 	{
 		$date_a = DateTimeFormat::local($event_a['start']);
 		$date_b = DateTimeFormat::local($event_b['start']);
@@ -223,7 +222,7 @@ class Event
 	 * @return void
 	 * @throws \Exception
 	 */
-	public static function delete($event_id)
+	public static function delete(int $event_id)
 	{
 		if ($event_id == 0) {
 			return;
@@ -242,7 +241,7 @@ class Event
 	 * @return int The new event id.
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function store($arr)
+	public static function store(array $arr): int
 	{
 		$event = [];
 		$event['id']        = intval($arr['id']        ?? 0);
@@ -317,7 +316,7 @@ class Event
 		return $event['id'];
 	}
 
-	public static function getItemArrayForId(int $event_id, array $item = []):array
+	public static function getItemArrayForId(int $event_id, array $item = []): array
 	{
 		if (empty($event_id)) {
 			return $item;
@@ -374,7 +373,7 @@ class Event
 		return $item;
 	}
 
-	public static function getItemArrayForImportedId(int $event_id, array $item = []):array
+	public static function getItemArrayForImportedId(int $event_id, array $item = []): array
 	{
 		if (empty($event_id)) {
 			return $item;
@@ -404,7 +403,7 @@ class Event
 	 * @return array Array with translations strings.
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function getStrings()
+	public static function getStrings(): array
 	{
 		// First day of the week (0 = Sunday).
 		$firstDay = DI::pConfig()->get(local_user(), 'system', 'first_day_of_week', 0);
@@ -477,7 +476,7 @@ class Event
 	 *
 	 * @todo We should replace this with a separate update function if there is some time left.
 	 */
-	private static function removeDuplicates(array $dates)
+	private static function removeDuplicates(array $dates): array
 	{
 		$dates2 = [];
 
@@ -500,7 +499,7 @@ class Event
 	 * @return array Query result
 	 * @throws \Exception
 	 */
-	public static function getListById($owner_uid, $event_id, $sql_extra = '')
+	public static function getListById(int $owner_uid, int $event_id, string $sql_extra = ''): array
 	{
 		$return = [];
 
@@ -536,7 +535,7 @@ class Event
 	 * @return array Query results.
 	 * @throws \Exception
 	 */
-	public static function getListByDate($owner_uid, $event_params, $sql_extra = '')
+	public static function getListByDate(int $owner_uid, array $event_params, string $sql_extra = ''): array
 	{
 		$return = [];
 
@@ -570,7 +569,7 @@ class Event
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function prepareListForTemplate(array $event_result)
+	public static function prepareListForTemplate(array $event_result): array
 	{
 		$event_list = [];
 
@@ -651,12 +650,12 @@ class Event
 	 * @param array  $events Query result for events.
 	 * @param string $format The output format (ical/csv).
 	 *
-	 * @param        $timezone
+	 * @param string $timezone Timezone (missing parameter!)
 	 * @return string Content according to selected export format.
 	 *
 	 * @todo  Implement timezone support
 	 */
-	private static function formatListForExport(array $events, $format)
+	private static function formatListForExport(array $events, string $format): string
 	{
 		$o = '';
 
@@ -757,7 +756,7 @@ class Event
 	 * @return array Query results.
 	 * @throws \Exception
 	 */
-	private static function getListByUserId($uid = 0)
+	private static function getListByUserId(int $uid = 0): array
 	{
 		$return = [];
 
@@ -797,7 +796,7 @@ class Event
 	 * @throws \Exception
 	 * @todo Respect authenticated users with events_by_uid().
 	 */
-	public static function exportListByUserId($uid, $format = 'ical')
+	public static function exportListByUserId(int $uid, string $format = 'ical'): array
 	{
 		$process = false;
 
@@ -845,7 +844,8 @@ class Event
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function getItemHTML(array $item) {
+	public static function getItemHTML(array $item): string
+	{
 		$same_date = false;
 		$finish    = false;
 
@@ -933,10 +933,11 @@ class Event
 	 * @return array The array with the location data.
 	 *  'name' => The name of the location,<br>
 	 * 'address' => The address of the location,<br>
-	 * 'coordinates' => Latitude‎ and longitude‎ (e.g. '48.864716,2.349014').<br>
+	 * 'coordinates' => Latitude and longitude (e.g. '48.864716,2.349014').<br>
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	private static function locationToArray($s = '') {
+	private static function locationToArray(string $s = ''): array
+	{
 		if ($s == '') {
 			return [];
 		}
@@ -981,7 +982,7 @@ class Event
 	 * @return bool
 	 * @throws \Exception
 	 */
-	public static function createBirthday($contact, $birthday)
+	public static function createBirthday(array $contact, string $birthday): bool
 	{
 		// Check for duplicates
 		$condition = [
@@ -1011,8 +1012,7 @@ class Event
 			'type'    => 'birthday',
 		];
 
-		self::store($values);
+		// Check if self::store() was success
-
+		return (self::store($values) > 0);
-		return true;
 	}
 }

src/Model/FContact.php

@@ -40,7 +40,7 @@ class FContact
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function getByURL($handle, $update = null)
+	public static function getByURL(string $handle, $update = null): array
 	{
 		$person = DBA::selectFirst('fcontact', [], ['network' => Protocol::DIASPORA, 'addr' => $handle]);
 		if (!DBA::isResult($person)) {
@@ -90,7 +90,7 @@ class FContact
 	 * @param array $arr The fcontact data
 	 * @throws \Exception
 	 */
-	public static function updateFromProbeArray($arr)
+	public static function updateFromProbeArray(array $arr)
 	{
 		$uriid = ItemURI::insert(['uri' => $arr['url'], 'guid' => $arr['guid']]);
 
@@ -122,12 +122,12 @@ class FContact
 	 * get a url (scheme://domain.tld/u/user) from a given Diaspora*
 	 * fcontact guid
 	 *
-	 * @param mixed $fcontact_guid Hexadecimal string guid
+	 * @param string $fcontact_guid Hexadecimal string guid
 	 *
-	 * @return string the contact url or null
+	 * @return string|null the contact url or null
 	 * @throws \Exception
 	 */
-	public static function getUrlByGuid($fcontact_guid)
+	public static function getUrlByGuid(string $fcontact_guid)
 	{
 		Logger::info('fcontact', ['guid' => $fcontact_guid]);
 

src/Model/GServer.php

@@ -2054,7 +2054,7 @@ class GServer
 	 * @return int
 	 * @throws Exception
 	 */
-	public static function getProtocol(int $gsid)
+	public static function getProtocol(int $gsid): int
 	{
 		if (empty($gsid)) {
 			return null;

src/Model/Log/ParsedLogIterator.php

@@ -60,7 +60,7 @@ class ParsedLogIterator implements \Iterator
 	 * @param string $filename	File to open
 	 * @return $this
 	 */
-	public function open(string $filename)
+	public function open(string $filename): ParsedLogIterator
 	{
 		$this->reader->open($filename);
 		return $this;
@@ -70,7 +70,7 @@ class ParsedLogIterator implements \Iterator
 	 * @param int $limit		Max num of lines to read
 	 * @return $this
 	 */
-	public function withLimit(int $limit)
+	public function withLimit(int $limit): ParsedLogIterator
 	{
 		$this->limit = $limit;
 		return $this;
@@ -80,7 +80,7 @@ class ParsedLogIterator implements \Iterator
 	 * @param array $filters		filters per column
 	 * @return $this
 	 */
-	public function withFilters(array $filters)
+	public function withFilters(array $filters): ParsedLogIterator
 	{
 		$this->filters = $filters;
 		return $this;
@@ -90,7 +90,7 @@ class ParsedLogIterator implements \Iterator
 	 * @param string $search	string to search to filter lines
 	 * @return $this
 	 */
-	public function withSearch(string $search)
+	public function withSearch(string $search): ParsedLogIterator
 	{
 		$this->search = $search;
 		return $this;
@@ -100,10 +100,10 @@ class ParsedLogIterator implements \Iterator
 	 * Check if parsed log line match filters.
 	 * Always match if no filters are set.
 	 *
-	 * @param ParsedLogLine $parsedlogline
+	 * @param ParsedLogLine $parsedlogline ParsedLogLine instance
-	 * @return bool
+	 * @return bool Wether the parse log line matches
 	 */
-	private function filter($parsedlogline)
+	private function filter(ParsedLogLine $parsedlogline): bool
 	{
 		$match = true;
 		foreach ($this->filters as $filter => $filtervalue) {
@@ -126,7 +126,7 @@ class ParsedLogIterator implements \Iterator
 	 * @param ParsedLogLine $parsedlogline
 	 * @return bool
 	 */
-	private function search($parsedlogline)
+	private function search(ParsedLogLine $parsedlogline): bool
 	{
 		if ($this->search != "") {
 			return strstr($parsedlogline->logline, $this->search) !== false;

src/Model/Photo.php

@@ -110,7 +110,7 @@ class Photo
 	 * @throws \Exception
 	 * @see   \Friendica\Database\DBA::select
 	 */
-	public static function getPhotosForUser($uid, $resourceid, array $conditions = [], array $params = [])
+	public static function getPhotosForUser(int $uid, string $resourceid, array $conditions = [], array $params = [])
 	{
 		$conditions["resource-id"] = $resourceid;
 		$conditions["uid"] = $uid;

src/Model/Profile.php

@@ -237,7 +237,7 @@ class Profile
 
 		if (!local_user()) {
 			$a->setCurrentTheme($profile['theme']);
-			$a->setCurrentMobileTheme(DI::pConfig()->get($a->getProfileOwner(), 'system', 'mobile_theme'));
+			$a->setCurrentMobileTheme(DI::pConfig()->get($a->getProfileOwner(), 'system', 'mobile_theme') ?? '');
 		}
 
 		/*

src/Model/User.php

@@ -134,7 +134,7 @@ class User
 	 *
 	 * @return array system account
 	 */
-	public static function getSystemAccount()
+	public static function getSystemAccount(): array
 	{
 		$system = Contact::selectFirst([], ['self' => true, 'uid' => 0]);
 		if (!DBA::isResult($system)) {
@@ -244,7 +244,7 @@ class User
 	 *
 	 * @return string actor account name
 	 */
-	public static function getActorName()
+	public static function getActorName(): string
 	{
 		$system_actor_name = DI::config()->get('system', 'actor_name');
 		if (!empty($system_actor_name)) {
@@ -278,7 +278,7 @@ class User
 	 * @return boolean
 	 * @throws Exception
 	 */
-	public static function exists($uid)
+	public static function exists(int $uid): bool
 	{
 		return DBA::exists('user', ['uid' => $uid]);
 	}
@@ -289,7 +289,7 @@ class User
 	 * @return array|boolean User record if it exists, false otherwise
 	 * @throws Exception
 	 */
-	public static function getById($uid, array $fields = [])
+	public static function getById(int $uid, array $fields = [])
 	{
 		return !empty($uid) ? DBA::selectFirst('user', $fields, ['uid' => $uid]) : [];
 	}
@@ -321,7 +321,7 @@ class User
 	 * @return array|boolean User record if it exists, false otherwise
 	 * @throws Exception
 	 */
-	public static function getByNickname($nickname, array $fields = [])
+	public static function getByNickname(string $nickname, array $fields = [])
 	{
 		return DBA::selectFirst('user', $fields, ['nickname' => $nickname]);
 	}
@@ -334,7 +334,7 @@ class User
 	 * @return integer user id
 	 * @throws Exception
 	 */
-	public static function getIdForURL(string $url)
+	public static function getIdForURL(string $url): int
 	{
 		// Avoid database queries when the local node hostname isn't even part of the url.
 		if (!Contact::isLocal($url)) {
@@ -380,7 +380,7 @@ class User
 	 * @param array $fields
 	 * @return array user
 	 */
-	public static function getFirstAdmin(array $fields = [])
+	public static function getFirstAdmin(array $fields = []) : array
 	{
 		if (!empty(DI::config()->get('config', 'admin_nickname'))) {
 			return self::getByNickname(DI::config()->get('config', 'admin_nickname'), $fields);
@@ -469,7 +469,7 @@ class User
 	 * @return boolean|array
 	 * @throws Exception
 	 */
-	public static function getOwnerDataByNick($nick)
+	public static function getOwnerDataByNick(string $nick)
 	{
 		$user = DBA::selectFirst('user', ['uid'], ['nickname' => $nick]);
 
@@ -488,7 +488,7 @@ class User
 	 * @return int group id
 	 * @throws Exception
 	 */
-	public static function getDefaultGroup($uid)
+	public static function getDefaultGroup(int $uid): int
 	{
 		$user = DBA::selectFirst('user', ['def_gid'], ['uid' => $uid]);
 		if (DBA::isResult($user)) {
@@ -512,7 +512,7 @@ class User
 	 * @throws HTTPException\ForbiddenException
 	 * @throws HTTPException\NotFoundException
 	 */
-	public static function getIdFromPasswordAuthentication($user_info, $password, $third_party = false)
+	public static function getIdFromPasswordAuthentication($user_info, string $password, bool $third_party = false)
 	{
 		// Addons registered with the "authenticate" hook may create the user on the
 		// fly. `getAuthenticationInfo` will fail if the user doesn't exist yet. If
@@ -580,7 +580,7 @@ class User
 	 * @return int User Id if authentication is successful
 	 * @throws HTTPException\ForbiddenException
 	 */
-	public static function getIdFromAuthenticateHooks($username, $password)
+	public static function getIdFromAuthenticateHooks(string $username, string $password): int
 	{
 		$addon_auth = [
 			'username'      => $username,
@@ -613,7 +613,7 @@ class User
 	 * - User array with at least the uid and the hashed password
 	 *
 	 * @param mixed $user_info
-	 * @return array
+	 * @return array|null Null if not found/determined
 	 * @throws HTTPException\NotFoundException
 	 */
 	public static function getAuthenticationInfo($user_info)
@@ -671,7 +671,7 @@ class User
 	 * @return string
 	 * @throws Exception
 	 */
-	public static function generateNewPassword()
+	public static function generateNewPassword(): string
 	{
 		return ucfirst(Strings::getRandomName(8)) . random_int(1000, 9999);
 	}
@@ -683,7 +683,7 @@ class User
 	 * @return bool
 	 * @throws Exception
 	 */
-	public static function isPasswordExposed($password)
+	public static function isPasswordExposed(string $password): bool
 	{
 		$cache = new CacheItemPool();
 		$cache->changeConfig([
@@ -712,7 +712,7 @@ class User
 	 * @param string $password
 	 * @return string
 	 */
-	private static function hashPasswordLegacy($password)
+	private static function hashPasswordLegacy(string $password): string
 	{
 		return hash('whirlpool', $password);
 	}
@@ -724,7 +724,7 @@ class User
 	 * @return string
 	 * @throws Exception
 	 */
-	public static function hashPassword($password)
+	public static function hashPassword(string $password): string
 	{
 		if (!trim($password)) {
 			throw new Exception(DI::l10n()->t('Password can\'t be empty'));
@@ -741,7 +741,7 @@ class User
 	 * @return bool
 	 * @throws Exception
 	 */
-	public static function updatePassword($uid, $password)
+	public static function updatePassword(int $uid, string $password): bool
 	{
 		$password = trim($password);
 
@@ -771,7 +771,7 @@ class User
 	 * @return bool
 	 * @throws Exception
 	 */
-	private static function updatePasswordHashed($uid, $pasword_hashed)
+	private static function updatePasswordHashed(int $uid, string $pasword_hashed): bool
 	{
 		$fields = [
 			'password' => $pasword_hashed,
@@ -792,7 +792,7 @@ class User
 	 * @param string $nickname The nickname that should be checked
 	 * @return boolean True is the nickname is blocked on the node
 	 */
-	public static function isNicknameBlocked($nickname)
+	public static function isNicknameBlocked(string $nickname): bool
 	{
 		$forbidden_nicknames = DI::config()->get('system', 'forbidden_nicknames', '');
 		if (!empty($forbidden_nicknames)) {
@@ -829,7 +829,7 @@ class User
 	 * @return string avatar link
 	 * @throws Exception
 	 */
-	public static function getAvatarUrl(array $user, string $size = ''):string
+	public static function getAvatarUrl(array $user, string $size = ''): string
 	{
 		if (empty($user['nickname'])) {
 			DI::logger()->warning('Missing user nickname key', ['trace' => System::callstack(20)]);
@@ -871,7 +871,7 @@ class User
 	 * @return string banner link
 	 * @throws Exception
 	 */
-	public static function getBannerUrl(array $user):string
+	public static function getBannerUrl(array $user): string
 	{
 		if (empty($user['nickname'])) {
 			DI::logger()->warning('Missing user nickname key', ['trace' => System::callstack(20)]);
@@ -913,7 +913,7 @@ class User
 	 * @throws ImagickException
 	 * @throws Exception
 	 */
-	public static function create(array $data)
+	public static function create(array $data): array
 	{
 		$return = ['user' => null, 'password' => ''];
 
@@ -1255,7 +1255,7 @@ class User
 
 	 * @throws Exception
 	 */
-	public static function block(int $uid, bool $block = true)
+	public static function block(int $uid, bool $block = true): bool
 	{
 		return DBA::update('user', ['blocked' => $block], ['uid' => $uid]);
 	}
@@ -1270,7 +1270,7 @@ class User
 	 * @throws HTTPException\InternalServerErrorException
 	 * @throws Exception
 	 */
-	public static function allow(string $hash)
+	public static function allow(string $hash): bool
 	{
 		$register = Register::getByHash($hash);
 		if (!DBA::isResult($register)) {
@@ -1316,7 +1316,7 @@ class User
 	 * @return bool True, if the deny was successfull
 	 * @throws Exception
 	 */
-	public static function deny(string $hash)
+	public static function deny(string $hash): bool
 	{
 		$register = Register::getByHash($hash);
 		if (!DBA::isResult($register)) {
@@ -1348,7 +1348,7 @@ class User
 	 * @throws ErrorException
 	 * @throws ImagickException
 	 */
-	public static function createMinimal(string $name, string $email, string $nick, string $lang = L10n::DEFAULT)
+	public static function createMinimal(string $name, string $email, string $nick, string $lang = L10n::DEFAULT): bool
 	{
 		if (empty($name) ||
 		    empty($email) ||
@@ -1418,7 +1418,7 @@ class User
 	 * @return NULL|boolean from notification() and email() inherited
 	 * @throws HTTPException\InternalServerErrorException
 	 */
-	public static function sendRegisterPendingEmail($user, $sitename, $siteurl, $password)
+	public static function sendRegisterPendingEmail(array $user, string $sitename, string $siteurl, string $password)
 	{
 		$body = Strings::deindent(DI::l10n()->t(
 			'
@@ -1461,7 +1461,7 @@ class User
 	 * @return NULL|boolean from notification() and email() inherited
 	 * @throws HTTPException\InternalServerErrorException
 	 */
-	public static function sendRegisterOpenEmail(L10n $l10n, $user, $sitename, $siteurl, $password)
+	public static function sendRegisterOpenEmail(L10n $l10n, array $user, string $sitename, string $siteurl, string $password)
 	{
 		$preamble = Strings::deindent($l10n->t(
 			'
@@ -1520,7 +1520,7 @@ class User
 	 * @return bool
 	 * @throws HTTPException\InternalServerErrorException
 	 */
-	public static function remove(int $uid)
+	public static function remove(int $uid): bool
 	{
 		if (empty($uid)) {
 			return false;
@@ -1574,7 +1574,7 @@ class User
 	 *    ]
 	 * @throws Exception
 	 */
-	public static function identities($uid)
+	public static function identities(int $uid): array
 	{
 		if (empty($uid)) {
 			return [];
@@ -1646,7 +1646,7 @@ class User
 	 * @param int $uid
 	 * @return bool
 	 */
-	public static function hasIdentities(int $uid):bool
+	public static function hasIdentities(int $uid): bool
 	{
 		if (empty($uid)) {
 			return false;
@@ -1679,7 +1679,7 @@ class User
 	 *
 	 * @throws Exception
 	 */
-	public static function getStatistics()
+	public static function getStatistics(): array
 	{
 		$statistics = [
 			'total_users'           => 0,
@@ -1732,10 +1732,10 @@ class User
 	 * @param string $order Order of the user list (Default is 'contact.name')
 	 * @param bool   $descending Order direction (Default is ascending)
 	 *
-	 * @return array The list of the users
+	 * @return array|bool The list of the users
 	 * @throws Exception
 	 */
-	public static function getList($start = 0, $count = Pager::ITEMS_PER_PAGE, $type = 'all', $order = 'name', bool $descending = false)
+	public static function getList(int $start = 0, int $count = Pager::ITEMS_PER_PAGE, string $type = 'all', string $order = 'name', bool $descending = false)
 	{
 		$param = ['limit' => [$start, $count], 'order' => [$order => $descending]];
 		$condition = [];

src/Module/DFRN/Notify.php

@@ -59,12 +59,13 @@ class Notify extends BaseModule
 		}
 	}
 
-	private static function dispatchPublic($postdata)
+	private static function dispatchPublic(array $postdata)
 	{
 		$msg = Diaspora::decodeRaw($postdata, '', true);
-		if (!$msg) {
+		if (!is_array($msg)) {
 			// We have to fail silently to be able to hand it over to the salmon parser
-			return false;
+			Logger::warning('Diaspora::decodeRaw() has failed for some reason.');
+			return;
 		}
 
 		// Fetch the corresponding public contact
@@ -88,10 +89,10 @@ class Notify extends BaseModule
 		System::xmlExit($ret, 'Done');
 	}
 
-	private static function dispatchPrivate($user, $postdata)
+	private static function dispatchPrivate(array $user, string $postdata)
 	{
 		$msg = Diaspora::decodeRaw($postdata, $user['prvkey'] ?? '');
-		if (!$msg) {
+		if (!is_array($msg)) {
 			System::xmlExit(4, 'Unable to parse message');
 		}
 

src/Module/DFRN/Poll.php

@@ -34,6 +34,6 @@ class Poll extends BaseModule
 	protected function rawContent(array $request = [])
 	{
 		$last_update = $request['last_update'] ?? '';
-		System::httpExit(OStatus::feed($this->parameters['nickname'], $last_update, 10), Response::TYPE_ATOM);
+		System::httpExit(OStatus::feed($this->parameters['nickname'], $last_update, 10) ?? '', Response::TYPE_ATOM);
 	}
 }

src/Module/Directory.php

@@ -112,7 +112,7 @@ class Directory extends BaseModule
 	 *
 	 * @throws \Exception
 	 */
-	public static function formatEntry(array $contact, $photo_size = 'photo')
+	public static function formatEntry(array $contact, string $photo_size = 'photo'): array
 	{
 		$itemurl = (($contact['addr'] != "") ? $contact['addr'] : $contact['url']);
 
@@ -166,7 +166,7 @@ class Directory extends BaseModule
 			'img_hover'    => $contact['name'],
 			'name'         => $contact['name'],
 			'details'      => $details,
-			'account_type' => Model\Contact::getAccountType($contact['contact-type']),
+			'account_type' => Model\Contact::getAccountType($contact['contact-type'] ?? ''),
 			'profile'      => $profile,
 			'location'     => $location_e,
 			'tags'         => $contact['pub_keywords'],

src/Network/Probe.php

@@ -1445,7 +1445,7 @@ class Probe
 	 * @return array|bool OStatus data or "false" on error or "true" on short mode
 	 * @throws HTTPException\InternalServerErrorException
 	 */
-	private static function ostatus($webfinger, $short = false)
+	private static function ostatus(array $webfinger, bool $short = false)
 	{
 		$data = [];
 

src/Profile/ProfileField/Collection/ProfileFields.php

@@ -33,9 +33,9 @@ class ProfileFields extends BaseCollection
 
 	/**
 	 * @param callable $callback
-	 * @return ProfileFields
+	 * @return ProfileFields (as an extended form of BaseCollection)
 	 */
-	public function map(callable $callback): ProfileFields
+	public function map(callable $callback): BaseCollection
 	{
 		return parent::map($callback);
 	}
@@ -43,9 +43,9 @@ class ProfileFields extends BaseCollection
 	/**
 	 * @param callable|null $callback
 	 * @param int           $flag
-	 * @return ProfileFields
+	 * @return ProfileFields as an extended version of BaseCollection
 	 */
-	public function filter(callable $callback = null, int $flag = 0): ProfileFields
+	public function filter(callable $callback = null, int $flag = 0): BaseCollection
 	{
 		return parent::filter($callback, $flag);
 	}

src/Protocol/Activity.php

@@ -212,7 +212,7 @@ final class Activity
 	 *
 	 * @return bool True, if the activity is hidden
 	 */
-	public function isHidden(string $activity)
+	public function isHidden(string $activity): bool
 	{
 		foreach (self::HIDDEN_ACTIVITIES as $hiddenActivity) {
 			if ($this->match($activity, $hiddenActivity)) {
@@ -231,7 +231,7 @@ final class Activity
 	 *
 	 * @return boolean
 	 */
-	public function match(string $haystack, string $needle)
+	public function match(string $haystack, string $needle): bool
 	{
 		return (($haystack === $needle) ||
 		        ((basename($needle) === $haystack) &&

src/Protocol/ActivityPub.php

@@ -104,12 +104,12 @@ class ActivityPub
 	 * @return array
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function fetchContent(string $url, int $uid = 0)
+	public static function fetchContent(string $url, int $uid = 0): array
 	{
 		return HTTPSignature::fetch($url, $uid);
 	}
 
-	private static function getAccountType($apcontact)
+	private static function getAccountType(array $apcontact): int
 	{
 		$accounttype = -1;
 
@@ -146,7 +146,7 @@ class ActivityPub
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function probeProfile($url, $update = true)
+	public static function probeProfile(string $url, bool $update = true): array
 	{
 		$apcontact = APContact::getByURL($url, $update);
 		if (empty($apcontact)) {
@@ -204,7 +204,7 @@ class ActivityPub
 	 * @param integer $uid User ID
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function fetchOutbox($url, $uid)
+	public static function fetchOutbox(string $url, int $uid)
 	{
 		$data = self::fetchContent($url, $uid);
 		if (empty($data)) {
@@ -235,7 +235,7 @@ class ActivityPub
 	 * @param integer $uid Optional user id
 	 * @return array Endpoint items
 	 */
-	public static function fetchItems(string $url, int $uid = 0)
+	public static function fetchItems(string $url, int $uid = 0): array
 	{
 		$data = self::fetchContent($url, $uid);
 		if (empty($data)) {
@@ -268,7 +268,7 @@ class ActivityPub
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function isSupportedByContactUrl($url, $update = null)
+	public static function isSupportedByContactUrl(string $url, $update = null)
 	{
 		return !empty(APContact::getByURL($url, $update));
 	}

src/Protocol/ActivityPub/Processor.php

@@ -94,7 +94,7 @@ class Processor
 	 *
 	 * @return string with replaced emojis
 	 */
-	private static function replaceEmojis(int $uri_id, string $body, array $emojis)
+	private static function replaceEmojis(int $uri_id, string $body, array $emojis): string
 	{
 		$body = strtr($body,
 			array_combine(
@@ -690,7 +690,7 @@ class Processor
 	 * @param string $url message URL
 	 * @return string with GUID
 	 */
-	private static function getGUIDByURL(string $url)
+	private static function getGUIDByURL(string $url): string
 	{
 		$parsed = parse_url($url);
 
@@ -711,7 +711,7 @@ class Processor
 	 * @param array $item
 	 * @return boolean Is the message wanted?
 	 */
-	private static function isSolicitedMessage(array $activity, array $item)
+	private static function isSolicitedMessage(array $activity, array $item): bool
 	{
 		// The checks are split to improve the support when searching why a message was accepted.
 		if (count($activity['receiver']) != 1) {
@@ -972,7 +972,7 @@ class Processor
 	 * @return int|bool New mail table row id or false on error
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	private static function postMail($activity, $item)
+	private static function postMail(array $activity, array $item)
 	{
 		if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 			Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
@@ -1113,7 +1113,7 @@ class Processor
 	 * @return string fetched message URL
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL)
+	public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL): string
 	{
 		if (!empty($child['receiver'])) {
 			$uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
@@ -1208,7 +1208,7 @@ class Processor
 	 * @param string $id      object ID
 	 * @return boolean true if message is accepted
 	 */
-	private static function acceptIncomingMessage(array $activity, string $id)
+	private static function acceptIncomingMessage(array $activity, string $id): bool
 	{
 		if (empty($activity['as:object'])) {
 			Logger::info('No object field in activity - accepted', ['id' => $id]);
@@ -1248,7 +1248,7 @@ class Processor
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function followUser($activity)
+	public static function followUser(array $activity)
 	{
 		$uid = User::getIdForURL($activity['object_id']);
 		if (empty($uid)) {
@@ -1326,7 +1326,7 @@ class Processor
 	 * @param array $activity
 	 * @throws \Exception
 	 */
-	public static function updatePerson($activity)
+	public static function updatePerson(array $activity)
 	{
 		if (empty($activity['object_id'])) {
 			return;
@@ -1342,7 +1342,7 @@ class Processor
 	 * @param array $activity
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function deletePerson($activity)
+	public static function deletePerson(array $activity)
 	{
 		if (empty($activity['object_id']) || empty($activity['actor'])) {
 			Logger::info('Empty object id or actor.');
@@ -1369,7 +1369,7 @@ class Processor
 	 * @param array $activity
 	 * @throws \Exception
 	 */
-	public static function blockAccount($activity)
+	public static function blockAccount(array $activity)
 	{
 		$cid = Contact::getIdForURL($activity['actor']);
 		if (empty($cid)) {
@@ -1392,7 +1392,7 @@ class Processor
 	 * @param array $activity
 	 * @throws \Exception
 	 */
-	public static function unblockAccount($activity)
+	public static function unblockAccount(array $activity)
 	{
 		$cid = Contact::getIdForURL($activity['actor']);
 		if (empty($cid)) {
@@ -1416,7 +1416,7 @@ class Processor
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function acceptFollowUser($activity)
+	public static function acceptFollowUser(array $activity)
 	{
 		$uid = User::getIdForURL($activity['object_actor']);
 		if (empty($uid)) {
@@ -1450,7 +1450,7 @@ class Processor
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function rejectFollowUser($activity)
+	public static function rejectFollowUser(array $activity)
 	{
 		$uid = User::getIdForURL($activity['object_actor']);
 		if (empty($uid)) {
@@ -1483,7 +1483,7 @@ class Processor
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function undoActivity($activity)
+	public static function undoActivity(array $activity)
 	{
 		if (empty($activity['object_id'])) {
 			return;
@@ -1508,7 +1508,7 @@ class Processor
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function undoFollowUser($activity)
+	public static function undoFollowUser(array $activity)
 	{
 		$uid = User::getIdForURL($activity['object_object']);
 		if (empty($uid)) {
@@ -1543,7 +1543,7 @@ class Processor
 	 * @param integer $cid Contact ID
 	 * @throws \Exception
 	 */
-	private static function switchContact($cid)
+	private static function switchContact(int $cid)
 	{
 		$contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
 		if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
@@ -1563,7 +1563,7 @@ class Processor
 	 * @return array
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	private static function getImplicitMentionList(array $parent)
+	private static function getImplicitMentionList(array $parent): array
 	{
 		$parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
 
@@ -1601,7 +1601,7 @@ class Processor
 	 * @param array $parent
 	 * @return string
 	 */
-	private static function removeImplicitMentionsFromBody(string $body, array $parent)
+	private static function removeImplicitMentionsFromBody(string $body, array $parent): string
 	{
 		if (DI::config()->get('system', 'disable_implicit_mentions')) {
 			return $body;

src/Protocol/ActivityPub/Receiver.php

@@ -84,8 +84,9 @@ class Receiver
 	 * @param         $header
 	 * @param integer $uid User ID
 	 * @throws \Exception
+	 * @todo Find type for $body/$header
 	 */
-	public static function processInbox($body, $header, $uid)
+	public static function processInbox($body, $header, int $uid)
 	{
 		$activity = json_decode($body, true);
 		if (empty($activity)) {
@@ -220,11 +221,11 @@ class Receiver
 	 * @param string  $object_id Object ID of the the provided object
 	 * @param integer $uid       User ID
 	 *
-	 * @return string with object type
+	 * @return string with object type or NULL
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	private static function fetchObjectType($activity, $object_id, $uid = 0)
+	private static function fetchObjectType(array $activity, string $object_id, int $uid = 0)
 	{
 		if (!empty($activity['as:object'])) {
 			$object_type = JsonLD::fetchElement($activity['as:object'], '@type');
@@ -268,7 +269,7 @@ class Receiver
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function prepareObjectData($activity, $uid, $push, &$trust_source)
+	public static function prepareObjectData(array $activity, int $uid, bool $push, bool &$trust_source): array
 	{
 		$id = JsonLD::fetchElement($activity, '@id');
 		if (!empty($id) && !$trust_source) {
@@ -458,7 +459,7 @@ class Receiver
 	 * @param array $receivers Array with receivers
 	 * @return integer user id;
 	 */
-	public static function getFirstUserFromReceivers($receivers)
+	public static function getFirstUserFromReceivers(array $receivers): int
 	{
 		foreach ($receivers as $receiver) {
 			if (!empty($receiver)) {
@@ -479,7 +480,7 @@ class Receiver
 	 * @param array   $signer       The signer of the post
 	 * @throws \Exception
 	 */
-	public static function processActivity($activity, string $body = '', int $uid = null, bool $trust_source = false, bool $push = false, array $signer = [])
+	public static function processActivity(array $activity, string $body = '', int $uid = null, bool $trust_source = false, bool $push = false, array $signer = [])
 	{
 		$type = JsonLD::fetchElement($activity, '@type');
 		if (!$type) {
@@ -818,7 +819,7 @@ class Receiver
 	 *
 	 * @return int   user id
 	 */
-	public static function getBestUserForActivity(array $activity)
+	public static function getBestUserForActivity(array $activity): int
 	{
 		$uid = 0;
 		$actor = JsonLD::fetchElement($activity, 'as:actor', '@id') ?? '';
@@ -844,7 +845,8 @@ class Receiver
 		return $uid;
 	}
 
-	public static function getReceiverURL($activity)
+	// @TODO Missing documentation
+	public static function getReceiverURL(array $activity): array
 	{
 		$urls = [];
 
@@ -876,9 +878,9 @@ class Receiver
 	 * @return array with receivers (user id)
 	 * @throws \Exception
 	 */
-	private static function getReceivers($activity, $actor, $tags = [], $fetch_unlisted = false)
+	private static function getReceivers(array $activity, string $actor, array $tags = [], bool $fetch_unlisted = false): array
 	{
-		$reply = $receivers = [];
+		$reply = $receivers = $profile = [];
 
 		// When it is an answer, we inherite the receivers from the parent
 		$replyto = JsonLD::fetchElement($activity, 'as:inReplyTo', '@id');
@@ -1005,7 +1007,7 @@ class Receiver
 	 * @return array with receivers (user id)
 	 * @throws \Exception
 	 */
-	private static function getReceiverForActor($actor, $tags, $receivers, $target_type, $profile)
+	private static function getReceiverForActor(string $actor, array $tags, array $receivers, int $target_type, array $profile): array
 	{
 		$basecondition = ['rel' => [Contact::SHARING, Contact::FRIEND, Contact::FOLLOWER],
 			'network' => Protocol::FEDERATED, 'archive' => false, 'pending' => false];
@@ -1047,13 +1049,12 @@ class Receiver
 	 * Tests if the contact is a valid receiver for this actor
 	 *
 	 * @param array  $contact
-	 * @param string $actor
 	 * @param array  $tags
 	 *
 	 * @return bool with receivers (user id)
 	 * @throws \Exception
 	 */
-	private static function isValidReceiverForActor($contact, $tags)
+	private static function isValidReceiverForActor(array $contact, array $tags): bool
 	{
 		// Are we following the contact? Then this is a valid receiver
 		if (in_array($contact['rel'], [Contact::SHARING, Contact::FRIEND])) {
@@ -1089,7 +1090,7 @@ class Receiver
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function switchContact($cid, $uid, $url)
+	public static function switchContact(int $cid, int $uid, string $url)
 	{
 		if (DBA::exists('contact', ['id' => $cid, 'network' => Protocol::ACTIVITYPUB])) {
 			Logger::info('Contact is already ActivityPub', ['id' => $cid, 'uid' => $uid, 'url' => $url]);
@@ -1108,7 +1109,7 @@ class Receiver
 	}
 
 	/**
-	 *
+	 * @TODO Fix documentation and type-hints
 	 *
 	 * @param $receivers
 	 * @param $actor
@@ -1135,14 +1136,14 @@ class Receiver
 	}
 
 	/**
-	 *
+	 * @TODO Fix documentation and type-hints
 	 *
 	 * @param       $object_data
 	 * @param array $activity
 	 *
 	 * @return mixed
 	 */
-	private static function addActivityFields($object_data, $activity)
+	private static function addActivityFields($object_data, array $activity)
 	{
 		if (!empty($activity['published']) && empty($object_data['published'])) {
 			$object_data['published'] = JsonLD::fetchElement($activity, 'as:published', '@value');
@@ -1262,7 +1263,7 @@ class Receiver
 	 * @param array $languages
 	 * @return array Languages
 	 */
-	public static function processLanguages(array $languages)
+	public static function processLanguages(array $languages): array
 	{
 		if (empty($languages)) {
 			return [];
@@ -1285,7 +1286,7 @@ class Receiver
 	 *
 	 * @return array with tags in a simplified format
 	 */
-	public static function processTags(array $tags)
+	public static function processTags(array $tags): array
 	{
 		$taglist = [];
 
@@ -1317,7 +1318,7 @@ class Receiver
 	 * @param array $emojis
 	 * @return array with emojis in a simplified format
 	 */
-	private static function processEmojis(array $emojis)
+	private static function processEmojis(array $emojis): array
 	{
 		$emojilist = [];
 
@@ -1343,7 +1344,7 @@ class Receiver
 	 *
 	 * @return array Attachments in a simplified format
 	 */
-	private static function processAttachments(array $attachments)
+	private static function processAttachments(array $attachments): array
 	{
 		$attachlist = [];
 
@@ -1460,7 +1461,7 @@ class Receiver
 	 *
 	 * @return array Questions in a simplified format
 	 */
-	private static function processQuestion(array $object)
+	private static function processQuestion(array $object): array
 	{
 		$question = [];
 
@@ -1518,10 +1519,10 @@ class Receiver
 	 * @param array $object
 	 * @param array $object_data
 	 *
-	 * @return array
+	 * @return array Object data (?)
 	 * @throws \Exception
 	 */
-	private static function getSource($object, $object_data)
+	private static function getSource(array $object, array $object_data): array
 	{
 		$object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/bbcode');
 		$object_data['source'] = JsonLD::fetchElement($object_data, 'source', '@value');
@@ -1650,10 +1651,10 @@ class Receiver
 	 *
 	 * @param array $object
 	 *
-	 * @return array
+	 * @return array|bool Object data or FALSE if $object does not contain @id element
 	 * @throws \Exception
 	 */
-	private static function processObject($object)
+	private static function processObject(array $object)
 	{
 		if (!JsonLD::fetchElement($object, '@id')) {
 			return false;
@@ -1767,7 +1768,7 @@ class Receiver
 			$object_data['question'] = self::processQuestion($object);
 		}
 
-		$receiverdata = self::getReceivers($object, $object_data['actor'], $object_data['tags'], true);
+		$receiverdata = self::getReceivers($object, $object_data['actor'] ?? '', $object_data['tags'], true);
 		$receivers = $reception_types = [];
 		foreach ($receiverdata as $key => $data) {
 			$receivers[$key] = $data['uid'];

src/Protocol/ActivityPub/Transmitter.php

@@ -68,7 +68,7 @@ class Transmitter
 	 * @param array $inboxes
 	 * @return array inboxes with added relay servers
 	 */
-	public static function addRelayServerInboxes(array $inboxes = [])
+	public static function addRelayServerInboxes(array $inboxes = []): array
 	{
 		foreach (Relay::getList(['inbox']) as $contact) {
 			$inboxes[$contact['inbox']] = $contact['inbox'];
@@ -83,7 +83,7 @@ class Transmitter
 	 * @param array $inboxes
 	 * @return array inboxes with added relay servers
 	 */
-	public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = [])
+	public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = []): array
 	{
 		$item = Post::selectFirst(['uid'], ['id' => $item_id]);
 		if (empty($item)) {

src/Protocol/DFRN.php

@@ -72,7 +72,7 @@ class DFRN
 	 * @return array importer
 	 * @throws \Exception
 	 */
-	public static function getImporter($cid, $uid = 0)
+	public static function getImporter(int $cid, int $uid = 0): array
 	{
 		$condition = ['id' => $cid, 'blocked' => false, 'pending' => false];
 		$contact = DBA::selectFirst('contact', [], $condition);
@@ -115,7 +115,7 @@ class DFRN
 	 * @throws \ImagickException
 	 * @todo  Find proper type-hints
 	 */
-	public static function entries($items, $owner)
+	public static function entries(array $items, array $owner): string
 	{
 		$doc = new DOMDocument('1.0', 'utf-8');
 		$doc->formatOutput = true;
@@ -152,7 +152,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function itemFeed(int $uri_id, int $uid, bool $conversation = false)
+	public static function itemFeed(int $uri_id, int $uid, bool $conversation = false): string
 	{
 		if ($conversation) {
 			$condition = ['parent-uri-id' => $uri_id];
@@ -222,7 +222,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  Find proper type-hints
 	 */
-	public static function mail(array $mail, array $owner)
+	public static function mail(array $mail, array $owner): string
 	{
 		$doc = new DOMDocument('1.0', 'utf-8');
 		$doc->formatOutput = true;
@@ -259,7 +259,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  Find proper type-hints
 	 */
-	public static function fsuggest($item, $owner)
+	public static function fsuggest(array $item, array $owner): string
 	{
 		$doc = new DOMDocument('1.0', 'utf-8');
 		$doc->formatOutput = true;
@@ -289,7 +289,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  Find proper type-hints
 	 */
-	public static function relocate($owner, $uid)
+	public static function relocate(array $owner, int $uid): string
 	{
 
 		/* get site pubkey. this could be a new installation with no site keys*/
@@ -346,9 +346,9 @@ class DFRN
 	 *
 	 * @return object XML root object
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
-	 * @todo  Find proper type-hints
+	 * @todo  Find proper type-hint for returned type
 	 */
-	private static function addHeader(DOMDocument $doc, $owner, $authorelement, $alternatelink = "", $public = false)
+	private static function addHeader(DOMDocument $doc, array $owner, string $authorelement, string $alternatelink = '', bool $public = false)
 	{
 
 		if ($alternatelink == "") {
@@ -428,8 +428,12 @@ class DFRN
 	 * viewer's timezone also, but first we are going to convert it from the birthday
 	 * person's timezone to GMT - so the viewer may find the birthday starting at
 	 * 6:00PM the day before, but that will correspond to midnight to the birthday person.
+	 *
+	 * @param int $uid User id
+	 * @param string $tz Time zone string, like UTC
+	 * @return string Formatted birthday string
 	 */
-	private static function determineNextBirthday($uid, $tz)
+	private static function determineNextBirthday(int $uid, string $tz): string
 	{
 		$birthday = '';
 
@@ -467,7 +471,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  Find proper type-hints
 	 */
-	private static function addAuthor(DOMDocument $doc, array $owner, $authorelement, $public)
+	private static function addAuthor(DOMDocument $doc, array $owner, string $authorelement, bool $public)
 	{
 		// Should the profile be "unsearchable" in the net? Then add the "hide" element
 		$hide = DBA::exists('profile', ['uid' => $owner['uid'], 'net-publish' => false]);
@@ -592,7 +596,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  Find proper type-hints
 	 */
-	private static function addEntryAuthor(DOMDocument $doc, $element, $contact_url, $item)
+	private static function addEntryAuthor(DOMDocument $doc, string $element, string $contact_url, array $item)
 	{
 		$author = $doc->createElement($element);
 
@@ -637,7 +641,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  Find proper type-hints
 	 */
-	private static function createActivity(DOMDocument $doc, $element, $activity, $uriid)
+	private static function createActivity(DOMDocument $doc, string $element, string $activity, int $uriid)
 	{
 		if ($activity) {
 			$entry = $doc->createElement($element);
@@ -703,7 +707,7 @@ class DFRN
 	 * @return void XML attachment object
 	 * @todo  Find proper type-hints
 	 */
-	private static function getAttachment($doc, $root, $item)
+	private static function getAttachment($doc, $root, array $item)
 	{
 		foreach (Post\Media::getByURIId($item['uri-id'], [Post\Media::DOCUMENT, Post\Media::TORRENT, Post\Media::UNKNOWN]) as $attachment) {
 			$attributes = ['rel' => 'enclosure',
@@ -737,7 +741,7 @@ class DFRN
 	 * @throws \ImagickException
 	 * @todo  Find proper type-hints
 	 */
-	private static function entry(DOMDocument $doc, $type, array $item, array $owner, $comment = false, $cid = 0, $single = false)
+	private static function entry(DOMDocument $doc, string $type, array $item, array $owner, bool $comment = false, int $cid = 0, bool $single = false)
 	{
 		$mentioned = [];
 
@@ -961,13 +965,12 @@ class DFRN
 	 * @param array  $owner   Owner record
 	 * @param array  $contact Contact record of the receiver
 	 * @param string $atom    Content that will be transmitted
-	 *
 	 * @param bool   $public_batch
 	 * @return int Deliver status. Negative values mean an error.
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function transmit($owner, $contact, $atom, $public_batch = false)
+	public static function transmit(array $owner, array $contact, string $atom, bool $public_batch = false)
 	{
 		if (!$public_batch) {
 			if (empty($contact['addr'])) {
@@ -1060,7 +1063,7 @@ class DFRN
 	 * @throws \ImagickException
 	 * @todo  Find good type-hints for all parameter
 	 */
-	private static function fetchauthor(\DOMXPath $xpath, \DOMNode $context, $importer, $element, $onlyfetch, $xml = "")
+	private static function fetchauthor(\DOMXPath $xpath, \DOMNode $context, array $importer, string $element, bool $onlyfetch, string $xml = ''): array
 	{
 		$author = [];
 		$author["name"] = XML::getFirstNodeValue($xpath, $element."/atom:name/text()", $context);
@@ -1280,7 +1283,7 @@ class DFRN
 	 * @return string XML string
 	 * @todo Find good type-hints for all parameter
 	 */
-	private static function transformActivity($xpath, $activity, $element)
+	private static function transformActivity($xpath, $activity, string $element): string
 	{
 		if (!is_object($activity)) {
 			return "";
@@ -1335,7 +1338,7 @@ class DFRN
 	 * @throws \Exception
 	 * @todo  Find good type-hints for all parameter
 	 */
-	private static function processMail($xpath, $mail, $importer)
+	private static function processMail($xpath, $mail, array $importer)
 	{
 		Logger::notice("Processing mails");
 
@@ -1364,7 +1367,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  Find good type-hints for all parameter
 	 */
-	private static function processSuggestion($xpath, $suggestion, $importer)
+	private static function processSuggestion($xpath, $suggestion, array $importer)
 	{
 		Logger::notice('Processing suggestions');
 
@@ -1383,7 +1386,7 @@ class DFRN
 	 * @param integer $from_cid
 	 * @return bool   Was the adding successful?
 	 */
-	private static function addSuggestion(int $uid, int $cid, int $from_cid, string $note = '')
+	private static function addSuggestion(int $uid, int $cid, int $from_cid, string $note = ''): bool
 	{
 		$owner = User::getOwnerDataById($uid);
 		$contact = Contact::getById($cid);
@@ -1440,7 +1443,7 @@ class DFRN
 	 * @throws \ImagickException
 	 * @todo  Find good type-hints for all parameter
 	 */
-	private static function processRelocation($xpath, $relocation, $importer)
+	private static function processRelocation($xpath, $relocation, array $importer): bool
 	{
 		Logger::notice("Processing relocations");
 
@@ -1510,7 +1513,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  set proper type-hints (array?)
 	 */
-	private static function updateContent($current, $item, $importer, $entrytype)
+	private static function updateContent(array $current, array $item, array $importer, int $entrytype)
 	{
 		$changed = false;
 
@@ -1542,7 +1545,7 @@ class DFRN
 	 * @throws \Exception
 	 * @todo  set proper type-hints (array?)
 	 */
-	private static function getEntryType($importer, $item)
+	private static function getEntryType(array $importer, array $item): int
 	{
 		if ($item["thr-parent"] != $item["uri"]) {
 			$community = false;
@@ -1638,7 +1641,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @todo  set proper type-hints (array?)
 	 */
-	private static function processVerbs($entrytype, $importer, &$item, &$is_like)
+	private static function processVerbs(int $entrytype, array $importer, array &$item, bool &$is_like)
 	{
 		Logger::info("Process verb ".$item["verb"]." and object-type ".$item["object-type"]." for entrytype ".$entrytype);
 
@@ -1734,7 +1737,7 @@ class DFRN
 	 * @return void
 	 * @todo set proper type-hints
 	 */
-	private static function parseLinks($links, &$item)
+	private static function parseLinks($links, array &$item)
 	{
 		$rel = "";
 		$href = "";
@@ -1772,7 +1775,7 @@ class DFRN
 	 * @param array $imporer
 	 * @return boolean Is the message wanted?
 	 */
-	private static function isSolicitedMessage(array $item, array $importer)
+	private static function isSolicitedMessage(array $item, array $importer): bool
 	{
 		if (DBA::exists('contact', ["`nurl` = ? AND `uid` != ? AND `rel` IN (?, ?)",
 			Strings::normaliseLink($item["author-link"]), 0, Contact::FRIEND, Contact::SHARING])) {
@@ -1807,12 +1810,13 @@ class DFRN
 	 * @param object $entry    entry elements
 	 * @param array  $importer Record of the importer user mixed with contact of the content
 	 * @param string $xml      xml
+	 * @param int $protocol Protocol
 	 * @return void
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 * @todo  Add type-hints
 	 */
-	private static function processEntry($header, $xpath, $entry, $importer, $xml, $protocol)
+	private static function processEntry(array $header, $xpath, $entry, array $importer, string $xml, int $protocol)
 	{
 		Logger::notice("Processing entries");
 
@@ -2070,6 +2074,9 @@ class DFRN
 			}
 		}
 
+		// Need to initialize variable, otherwise E_NOTICE will happen
+		$is_like = false;
+
 		if (!self::processVerbs($entrytype, $importer, $item, $is_like)) {
 			Logger::info("Exiting because 'processVerbs' told us so");
 			return;
@@ -2163,7 +2170,7 @@ class DFRN
 	 * @throws \Exception
 	 * @todo  set proper type-hints
 	 */
-	private static function processDeletion($xpath, $deletion, $importer)
+	private static function processDeletion($xpath, $deletion, array $importer)
 	{
 		Logger::notice("Processing deletions");
 		$uri = null;
@@ -2224,9 +2231,8 @@ class DFRN
 	 * @return integer Import status
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
-	 * @todo  set proper type-hints
 	 */
-	public static function import($xml, $importer, $protocol, $direction)
+	public static function import(string $xml, array $importer, int $protocol, int $direction): int
 	{
 		if ($xml == "") {
 			return 400;
@@ -2365,7 +2371,7 @@ class DFRN
 	 *
 	 * @return string activity verb
 	 */
-	private static function constructVerb(array $item)
+	private static function constructVerb(array $item): string
 	{
 		if ($item['verb']) {
 			return $item['verb'];
@@ -2373,7 +2379,8 @@ class DFRN
 		return Activity::POST;
 	}
 
-	private static function tgroupCheck($uid, $item)
+	// @TODO Documentation missing
+	private static function tgroupCheck(int $uid, array $item): bool
 	{
 		$mention = false;
 
@@ -2421,12 +2428,12 @@ class DFRN
 	 * item is assumed to be up-to-date.  If the timestamps are equal it
 	 * assumes the update has been seen before and should be ignored.
 	 *
-	 * @param $existing
+	 * @param array $existing
-	 * @param $update
+	 * @param array $update
 	 * @return bool
 	 * @throws \Exception
 	 */
-	private static function isEditedTimestampNewer($existing, $update)
+	private static function isEditedTimestampNewer(array $existing, array $update): bool
 	{
 		if (empty($existing['edited'])) {
 			return true;
@@ -2449,7 +2456,7 @@ class DFRN
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function isSupportedByContactUrl($url)
+	public static function isSupportedByContactUrl(string $url): bool
 	{
 		$probe = Probe::uri($url, Protocol::DFRN);
 		return $probe['network'] == Protocol::DFRN;

src/Util/HTTPSignature.php

@@ -708,7 +708,6 @@ class HTTPSignature
 			}
 		}
 
-		// @TODO really a notice or more a warning?
 		Logger::notice('Key could not be fetched', ['url' => $url, 'actor' => $actor]);
 		return [];
 	}

src/Util/Strings.php

@@ -165,7 +165,7 @@ class Strings
 	 * @return string Formatted network name
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function formatNetworkName($network, $url = '')
+	public static function formatNetworkName(string $network, string $url = ''): string
 	{
 		if ($network != '') {
 			if ($url != '') {
@@ -176,6 +176,8 @@ class Strings
 
 			return $network_name;
 		}
+
+		return '';
 	}
 
 	/**
@@ -187,7 +189,7 @@ class Strings
 	 *
 	 * @return string		Transformed string.
 	 */
-	public static function deindent($text, $chr = "[\t ]", $count = NULL)
+	public static function deindent(string $text, string $chr = "[\t ]", int $count = null)
 	{
 		$lines = explode("\n", $text);
 

src/Worker/Delivery.php

@@ -269,7 +269,7 @@ class Delivery
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	private static function deliverDFRN($cmd, $contact, $owner, $items, $target_item, $public_message, $top_level, $followup, $server_protocol)
+	private static function deliverDFRN(string $cmd, array $contact, array $owner, array $items, array $target_item, bool $public_message, bool $top_level, bool $followup, int $server_protocol)
 	{
 		// Transmit Diaspora reshares via Diaspora if the Friendica contact support Diaspora
 		if (Diaspora::isReshare($target_item['body'] ?? '') && !empty(FContact::getByURL($contact['addr'], false))) {
@@ -384,7 +384,7 @@ class Delivery
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	private static function deliverDiaspora($cmd, $contact, $owner, $items, $target_item, $public_message, $top_level, $followup)
+	private static function deliverDiaspora(string $cmd, array $contact, array $owner, array $items, array $target_item, bool $public_message, bool $top_level, bool $followup)
 	{
 		// We don't treat Forum posts as "wall-to-wall" to be able to post them via Diaspora
 		$walltowall = $top_level && ($owner['id'] != $items[0]['contact-id']) & ($owner['account-type'] != Model\User::ACCOUNT_TYPE_COMMUNITY);
@@ -478,7 +478,7 @@ class Delivery
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	private static function deliverMail($cmd, $contact, $owner, $target_item, $thr_parent)
+	private static function deliverMail(string $cmd, array $contact, array $owner, array $target_item, array $thr_parent)
 	{
 		if (DI::config()->get('system','imap_disabled')) {
 			return;

src/Worker/Directory.php

@@ -34,7 +34,7 @@ use Friendica\Network\HTTPClient\Client\HttpClientAccept;
  */
 class Directory
 {
-	public static function execute($url = '')
+	public static function execute(string $url = '')
 	{
 		$dir = Search::getGlobalDirectory();
 

tests/Util/AppDouble.php

@@ -43,7 +43,7 @@ class AppDouble extends App
 		$this->isLoggedIn = $isLoggedIn;
 	}
 
-	public function isLoggedIn()
+	public function isLoggedIn(): bool
 	{
 		return $this->isLoggedIn;
 	}