define and start using single_text_context()

9unit.c

@@ -30,6 +30,9 @@
 // data required by the context management functions
 typedef struct ContextData ContextData;
 
+// data required to run a single test with a label
+typedef struct SingleTestContext SingleTestContext;
+
 struct ContextData
 {
 	const char *old_c; // previous context
@@ -38,6 +41,12 @@ struct ContextData
 	char *new_fc; // new full context
 };
 
+struct SingleTestContext
+{
+	void *ptr; // the state's previous ptr value
+	TestResult (*test)(TestState *); // the test to run
+};
+
 // Internal Prototypes
 
 static void init_TestState(TestState *);
@@ -48,6 +57,7 @@ static void report(const char *);
 static void build_new_context(TestState *, ContextData *);
 static void display_context(TestState *);
 static void restore_context(TestState *, ContextData *);
+static void run_single_test_context(TestState *);
 
 // Public Functions
 
@@ -147,6 +157,21 @@ test_context(
 	else (*test)(s);
 }
 
+void
+single_test_context(
+	TestState *s,
+	const char *label,
+	TestResult (*test)(TestState *)
+)
+{
+	if (!s) return;
+	SingleTestContext stc;
+	stc.ptr = s->ptr;
+	stc.test = test;
+	s->ptr = &stc;
+	test_context(s, label, run_single_test_context);
+}
+
 // Internal Functions
 
 static void
@@ -243,4 +268,12 @@ restore_context(TestState *s, ContextData *cd)
 	free(cd->new_fc);
 }
 
+static void
+run_single_test_context(TestState *s)
+{
+	SingleTestContext *stc = s->ptr;
+	s->ptr = stc->ptr;
+	run_test(s, stc->test);
+}
+
 //jl