don't show assert message boxes in debug build but throw an exception if an assert unexpectedly fails; do check that expected asserts are generated

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@57459 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/testprec.h

@@ -6,3 +6,24 @@
     (defined(__GNUC__) && (__GNUC__ >= 3))
     #define wxHAVE_U_ESCAPE
 #endif
+
+// thrown when assert fails in debug build
+class TestAssertFailure { };
+
+// macro to use for the functions which are supposed to fail an assertion
+#ifdef __WXDEBUG__
+    // some old cppunit versions don't define CPPUNIT_ASSERT_THROW so roll our
+    // own
+    #define WX_ASSERT_FAILS_WITH_ASSERT(cond) \
+        { \
+            bool throwsAssert = false; \
+            try { cond ; } \
+            catch ( const TestAssertFailure& ) { throwsAssert = true; } \
+            if ( !throwsAssert ) \
+                CPPUNIT_FAIL("expected assertion not generated"); \
+        }
+#else
+    // there are no assertions in non-debug build so just check that it fails
+    #define WX_ASSERT_FAILS_WITH_ASSERT(cond) CPPUNIT_ASSERT(!(cond))
+#endif
+