JaxrsExceptionTestHelper#assertContainsError should report actual err…

…ors (#380)

* Change the error message reported by assertContainsError so that it
  reports the expected ErrorMessage and also all the actual errors. This
  will allow users to determine the problem by having the actual errors
  for inspection.

Closes #376

src/main/java/org/kiwiproject/test/jaxrs/exception/JaxrsExceptionTestHelper.java

@@ -119,14 +119,14 @@ public static void assertHasErrors(Response response, List<ErrorMessage> errorMe
     public static ErrorMessage assertContainsError(Response response, int statusCode, String substring) {
         var jaxrsException = toJaxrsException(response);
 
-        return jaxrsException.getErrors()
-                .stream()
+        var errors = jaxrsException.getErrors();
+        return errors.stream()
                 .filter(error -> matchesArguments(error, statusCode, substring))
                 .findFirst()
                 .orElseThrow(() -> {
                     var assertErrorMessage =
-                            f("Response does not contain an ErrorMessage having status {} and message containing: {}",
-                                    statusCode, substring);
+                            f("Response does not contain an ErrorMessage having status {} and message containing: '{}'. Actual errors: {}",
+                                    statusCode, substring, errors);
                     return new AssertionError(assertErrorMessage);
                 });
     }

src/test/java/org/kiwiproject/test/jaxrs/exception/JaxrsExceptionTestHelperTest.java

@@ -267,8 +267,8 @@ void shouldThrow_WhenResponseDoesNotContainTheError(int statusCode, String subst
             assertThatThrownBy(() ->
                     JaxrsExceptionTestHelper.assertContainsError(response, statusCode, substring))
                     .isInstanceOf(AssertionError.class)
-                    .hasMessage("Response does not contain an ErrorMessage having status %d and message containing: %s",
-                            statusCode, substring);
+                    .hasMessage("Response does not contain an ErrorMessage having status %d and message containing: '%s'. Actual errors: %s",
+                            statusCode, substring, jaxrsException.getErrors());
         }
     }
 }