skipIf(Predicate)

[xenoterracide]

Feature summary

So the problem with the example is there isn't always a valid greater than, and I'm making up versions that I won't be generating just to fill it in. I've realized it would be nice to have a way to skip or pass a single assertion if it met certain criteria

I'd change the impossible values to null and do

assertThat(...).skipIf(v -> greaterThan == null);

Obviously I can just do an if statement or another test. Somehow to me this feels cleaner, as technically the code still executes.

BDD given/assumeThat isn't the same, because I don't want to skip the entire test, I just want to not fail this 1 assertion.

it'd be almost equivalent to the following, except the assertion wouldn't be called at all here, and it should be with skipIf

    if (greaterThan != null) assertThat(new ComparableVersion(semv.toString()))
      .describedAs("mvn")
      .isGreaterThan(new ComparableVersion(greaterThan));

could also call it passIf, unless (very perl-ish). I thought of using filter too but I think that'd be confusing. I suppose when thinking about chaining though

// would pass even if lessThan is false
assertThat(...).passIf( t -> greaterThan == null).isLessThan(...).isGreaterThan(greaterThan);
// would fail if less than is false but wouldn't run greater than, works like filter
assertThat(...).isLessThan(...).skipIf( t -> greaterThan == null).isGreaterThan(greaterThan);
// honestly seems same as passif to me because perl. Those only make sense at beginning or end of chain. 
assertThat(...).isLessThan(...).isGreaterThan(greaterThan).unless( t -> greaterThan == null );

Possibly has some additional benefit if integrating with Soft Assertions (I find "Soft" weirdly named, and didn't know they were a thing before now), as maybe they can "log" this.

note: I'm fairly confident that this comparison stuff is not the first time I've wanted this.

Example

class SemverBuilderTest {

  @ParameterizedTest
  @ArgumentsSource(VersionProvider.class)
  void gitMetadata(GitMetadata gitMetadata, String expected, String comp, String lessThan, String greaterThan) {
    var semv = new SemverBuilder(gitMetadata).build();
    assertThat(semv).describedAs("equal").isEqualTo(new Semver(expected));
    assertThat(semv).describedAs("comparing").isEqualByComparingTo(new Semver(comp));
    assertThat(semv).describedAs("lessThan").isLessThan(new Semver(lessThan));
    assertThat(new ComparableVersion(semv.toString())).describedAs("mvn").isLessThan(new ComparableVersion(lessThan));
    assertThat(new ComparableVersion(semv.toString()))
      .describedAs("mvn")
      .isGreaterThan(new ComparableVersion(greaterThan));
  }

  static class VersionProvider implements ArgumentsProvider {

    @Override
    public Stream<? extends Arguments> provideArguments(ExtensionContext context) {
      return Stream.of(
        arguments(
          new GitMetadataInfo(0, GitStatus.NO_REPO, null, null),
          "0.0.0-alpha.0.0",
          "0.0.0-alpha.0.0",
          "0.0.0-alpha.0.1",
          "0.0.0-alpha.0.0+0" // not something we're generating
        ),
        arguments(
          new GitMetadataInfo(0, GitStatus.CLEAN, "abcdef10", null),
          "0.0.0-alpha.0.0+abcdef10",
          "0.0.0-alpha.0.0",
          "0.0.0-alpha.0.1",
          "0.0.0-alpha.0" // not something we're generating
        ),
        arguments(
          new GitMetadataInfo(0, GitStatus.DIRTY, "abcdef10", null),
          "0.0.0-alpha.0.0+abcdef10.dirty",
          "0.0.0-alpha.0.0",
          "0.0.0-alpha.0.1",
          "0.0.0-alpha.0"
        )
      );
    }
  }

[joel-costigliola]

Have you tried using satisfies with a consumer implementing you specific needs ?

[xenoterracide]

Unless I'm mistaken satisfies doesn't at all do what I'm proposing with a skipIf because I would still just end up using an if statement to not fail.