Improve configuration error handling of `HttpAppender`

[ppkarwasz]

As reported in this SO question if the HTTP appender does not have a configured layout, it fails with an NPE.

The correct behavior should be:

• issue a status logger message at level ERROR,
• return null.

[Suvrat1629]

@ppkarwasz
I have made the necessary changes in the HttpAppender.java file but i don't know how and what changes are required in the HttpAppenderTest.java. I did try adding some test cases but i got the following error on testing

sorry for my lack of understanding about testing but is it necessary to write test cases to check the (layout == null) behaviour

[ppkarwasz]

What you want to test is the behavior of the Builder class. Since HttpAppenderTest is a heavy test that starts up an HTTP server, I would rather create a new HttpAppenderBuilderTest to test the builder.

The builder needs to test that the required properties (name, url and layout) are present, before creating the appender. So, for example, you could test that:

HttpAppender.newBuilder()
    .setName("HTTP")
    .setUrl(new URL("https://localhost"))
    .build();

returns null and logs an ERROR status logger message. To capture the status logger messages for a test case, we have an @UsingStatusListener annotation that injects a ListStatusListener into the test parameters. The @UsingStatusListener annotation is for example used here.

logging-log4j2/log4j-core-test/src/test/java/org/apache/logging/log4j/core/pattern/HighlightConverterTest.java

Lines 195 to 211 in 6e3f2e2

	@Test
	@UsingStatusListener
	void testNoAnsiNonEmpty(final ListStatusListener listener) {
	final String[] options = {"%-5level: %msg", PatternParser.DISABLE_ANSI + "=true"};
	final HighlightConverter converter = HighlightConverter.newInstance(null, options);
	assertNotNull(converter);
	assertThat(listener.findStatusData(Level.WARN)).isEmpty();
	final LogEvent event = Log4jLogEvent.newBuilder()
	.setLevel(Level.INFO)
	.setLoggerName("a.b.c")
	.setMessage(new SimpleMessage("message in a bottle"))
	.build();
	final StringBuilder buffer = new StringBuilder();
	converter.format(event, buffer);
	assertEquals("INFO : message in a bottle", buffer.toString());
	}

[Suvrat1629]

I did write the test cases but i am facing a weird problem, my HttpAppenderBuilderTest.java is not able to find the required dependencies is there some xml file or something that i have to write? HttpAppenderBuilderTest.java is not even able to find the dependencies present in the HttpAppenderTest.java. Almost none of the import statements are working. Could you pleasae guide me with what i could possibly do to fix this

[vy]

@Suvrat1629, I presume you mean you cannot build and/or run tests in your IDE. If you use IntelliJ IDEA, install everything first (i.e. ./mvnw install -DskipTests) and then use Reload All Maven Projects Incrementally action – it is the reload button in the Maven side window. For further details, see the development instructions.

[Suvrat1629]

@vy
Thanks for the response,
I will follow the steps you have given me and try to get back to this issue