#11 Be more failsafe w.r.t. annotations

README.md

@@ -39,3 +39,6 @@ If you change the tested code in a manner you consider *valid*, you can approve
 
 ## Requirements
 Java 8
+
+## Pitfalls
+*Always* annotate test classes with `@GoldenMasterTest`, and use *only* `@GoldenMasterRun` for the test methods (cf. this [issue](https://github.com/maxbechtold/golden-master/issues/11))

src/main/java/maxbe/goldenmaster/approval/ApprovalIdResolver.java

@@ -18,7 +18,7 @@ public String resolveApprovalIdFor(ExtensionContext context) {
     }
 
     private String getApprovalId(ExtensionContext context) {
-        if (!GoldenMasterRun.AUTO_ID.equals(goldenMasterRunAnnotation.id())) {
+        if (goldenMasterRunAnnotation != null && !GoldenMasterRun.AUTO_ID.equals(goldenMasterRunAnnotation.id())) {
             return goldenMasterRunAnnotation.id();
         }
         return context.getRequiredTestMethod().getName();

src/main/java/maxbe/goldenmaster/junit/extension/RunInvocationContextProvider.java

@@ -43,9 +43,10 @@ public RunInvocationContextProvider() throws IOException {
         outputFile = File.createTempFile("goldenmaster_recording_" + System.currentTimeMillis(), ".txt");
     }
 
+    // FIXME #11 Currently, the harness fails with multiple TestDescriptors, see warning when using @GoldenMasterRun with @Test
     @Override
     public boolean supportsTestTemplate(ExtensionContext context) {
-        return true;
+        return getSupportedAnnotation(context) != null;
     }
 
     @Override
@@ -55,7 +56,7 @@ public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContex
     }
 
     private int determineRepetitions(ExtensionContext context) {
-        GoldenMasterRun goldenMasterAnnotation = getAnnotation(context);
+        GoldenMasterRun goldenMasterAnnotation = getSupportedAnnotation(context);
         if (goldenMasterAnnotation == null) {
             return GoldenMasterRun.DEFAULT_REPETITIONS;
         }
@@ -66,8 +67,8 @@ private int determineRepetitions(ExtensionContext context) {
         return repetitions;
     }
 
-    private GoldenMasterRun getAnnotation(ExtensionContext context) {
-        return context.getElement().get().getAnnotation(GoldenMasterRun.class);
+    private GoldenMasterRun getSupportedAnnotation(ExtensionContext context) {
+        return context.getElement().map(element -> element.getAnnotation(GoldenMasterRun.class)).orElse(null);
     }
 
     @Override
@@ -81,7 +82,7 @@ public void beforeAll(ExtensionContext context) throws Exception {
 
     @Override
     public void beforeEach(ExtensionContext context) throws Exception {
-        String runId = new ApprovalIdResolver(getAnnotation(context)).resolveRunIdFor(context);
+        String runId = new ApprovalIdResolver(getSupportedAnnotation(context)).resolveRunIdFor(context);
         Path basePath = Paths.get("src", "test", "resources", "approved");
         pathMapper = new TemplatedTestPathMapper<>(context, basePath, runId);
     }
@@ -93,7 +94,7 @@ public void afterEach(ExtensionContext context) throws Exception {
                 .withConverter(new FileConverter())//
                 .withReporter(get(context, Reporter.class, REPORTER_KEY)).build();
 
-        ApprovalIdResolver approvalIdResolver = new ApprovalIdResolver(getAnnotation(context));
+        ApprovalIdResolver approvalIdResolver = new ApprovalIdResolver(getSupportedAnnotation(context));
 
         String fileName = approvalIdResolver.resolveApprovalIdFor(context) + ".approved";
         approval.verify(outputFile, Paths.get(fileName));
@@ -112,7 +113,12 @@ public void afterAll(ExtensionContext context) throws Exception {
     }
 
     private <T> T get(ExtensionContext context, Class<T> type, String key) {
-        return getStore(context).get(key, type);
+        T element = getStore(context).get(key, type);
+        if (element == null) {
+            throw new RuntimeException(String.format("Did not find element for key '%s', did you annotate your class with @%s?", 
+                    key, GoldenMasterTest.class.getSimpleName()));
+        }
+        return element;
     }
 
     private Store getStore(ExtensionContext context) {

src/test/java/maxbe/goldenmaster/approval/ApprovalIdResolverTest.java

@@ -23,6 +23,14 @@ void setUp() {
         Mockito.doReturn("[123]").when(context).getDisplayName();
     }
 
+    @Test
+    void noExceptionIfNoAnnotationPresent() throws Exception {
+        ApprovalIdResolver resolver = new ApprovalIdResolver(null);
+
+        String approvalId = resolver.resolveApprovalIdFor(context);
+
+        assertThat(approvalId).isEqualTo(someMethod().getName());
+    }
     @Test
     void resolvesIdIfSpecified() throws Exception {
         String testId = "test-id";