doc: Add example for cmocka test case.
diff --git a/doc/mainpage.dox b/doc/mainpage.dox
index 76d6500..0e2664b 100644
--- a/doc/mainpage.dox
+++ b/doc/mainpage.dox
@@ -42,4 +42,33 @@
TODO Explain mock objects.
+@section main-test A CMocka test
+
+CMocka unit test cases are functions with the signature void function(void **state).
+CMocka test applications initialize a table with test case function pointers
+using unit_test() macros. This table is then passed to the run_tests() macro to
+execute the tests. run_tests() sets up the appropriate exception / signal
+handlers and other data structures prior to running each test function. When a
+unit test is complete run_tests() performs various checks to determine whether
+the test succeeded.
+
+@code
+#include <stdarg.h>
+#include <stddef.h>
+#include <setjmp.h>
+#include <cmockery.h>
+
+/* A test case that does nothing and succeeds. */
+void null_test_success(void **state) {
+}
+
+int main(void) {
+ const UnitTest tests[] = {
+ unit_test(null_test_success),
+ };
+
+ return run_tests(tests);
+}
+@endcode
+
*/
