kunit: test: add the concept of expectations

Add support for expectations, which allow properties to be specified and
then verified in tests.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib/kunit/test.c

@@ -120,6 +120,68 @@ static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
 			      test_case->name);
 }
 
+static void kunit_print_string_stream(struct kunit *test,
+				      struct string_stream *stream)
+{
+	struct string_stream_fragment *fragment;
+	char *buf;
+
+	buf = string_stream_get_string(stream);
+	if (!buf) {
+		kunit_err(test,
+			  "Could not allocate buffer, dumping stream:\n");
+		list_for_each_entry(fragment, &stream->fragments, node) {
+			kunit_err(test, fragment->fragment);
+		}
+		kunit_err(test, "\n");
+	} else {
+		kunit_err(test, buf);
+		kunit_kfree(test, buf);
+	}
+}
+
+static void kunit_fail(struct kunit *test, struct kunit_assert *assert)
+{
+	struct string_stream *stream;
+
+	kunit_set_failure(test);
+
+	stream = alloc_string_stream(test, GFP_KERNEL);
+	if (!stream) {
+		WARN(true,
+		     "Could not allocate stream to print failed assertion in %s:%d\n",
+		     assert->file,
+		     assert->line);
+		return;
+	}
+
+	assert->format(assert, stream);
+
+	kunit_print_string_stream(test, stream);
+
+	WARN_ON(string_stream_destroy(stream));
+}
+
+void kunit_do_assertion(struct kunit *test,
+			struct kunit_assert *assert,
+			bool pass,
+			const char *fmt, ...)
+{
+	va_list args;
+
+	if (pass)
+		return;
+
+	va_start(args, fmt);
+
+	assert->message.fmt = fmt;
+	assert->message.va = &args;
+
+	kunit_fail(test, assert);
+
+	va_end(args);
+}
+
 void kunit_init_test(struct kunit *test, const char *name)
 {
 	spin_lock_init(&test->lock);