How to mock manifest entries when unit testing with jcabi-manifests?

Question

This is one of the rare cases in which the official documentation of an API is severely lacking synchronization with the actual provided API.

So, the jcabi-manifests API documentation clearly states here that manifest entries can be statically mocked using the utility class Manifests. Unfortunately, the static methods described in the mentioned page - e.g. inject(), snapshot(), revert() - are missing from the actual API.

Has anybody been able to use the manifest mocking feature supposedly being delivered with jcabi-manifests? If yes, how?

Answer 1

Looks like the documentation is indeed a bit messy. You need version 0.8.2. This is where all that mocking functions still exist. But a better way of mocking exists in the latest version. Instead of using static methods, pass an instance of Manifests to your class and mock the entire instance of it. In the latest version we got rid of static methods, since they are very difficult to test in concurrent threads. If you have more issues, submit a ticket to Github, we'll try to help: https://github.com/jcabi/jcabi-manifests/issues

Answer 2

For more recent versions of Manifests (current is 1.1), the solution is to use Manifests.DEFAULT which is a map that can be manipulated. So for my tests what I did was adding the property I wanted and then remove it as part of the tear down method:

  @After
  public void tearDown() {
    Manifests.DEFAULT.remove("my-client-version");
  }

  @Test
  public void testGetClientVersion() {
    Manifests.DEFAULT.put("my-client-version", "1.2.3");
    final String actual = VersionUtils.getClientVersion();
    assertThat(actual).isEqualTo("1.2.3");
  }