Troubleshoot mismatched AssertJ AbstractStringAssert.isEqualTo("")

[timtebeek]

This is a recipe that originates with Picnic: https://error-prone.picnic.tech/refasterrules/AssertJStringRules/#abstractstringassertstringisempty

At present it fails to convert this test case

@Test
void convertsIsEqualToEmptyString() {
    rewriteRun(
      //language=java
      java(
        """
          import static org.assertj.core.api.Assertions.assertThat;
          class Test {
              void test() {
                  assertThat("test").isEqualTo("");
              }
          }
          """,
        """
          import static org.assertj.core.api.Assertions.assertThat;
          class Test {
              void test() {
                  assertThat("test").isEmpty();
              }
          }
          """
      )
    );
}

As discovered on

• Add Picnic AssertJ rules to AssertJ best practices rewrite-testing-frameworks#527

Not yet sure if the fix should go into the generated recipe, or in the matchers used in the generated recipe. Figured log this as a pseudo issue to more easily see the generated recipe.

[timtebeek]

Setting a breakpoint in tech.picnic.errorprone.refasterrules.AssertJStringRulesRecipes.AbstractStringAssertStringIsEmptyRecipe#getVisitor shows that the before matcher does not match the input in the case.

[timtebeek]

Continued here; as the problem looks to be with the matcher, not the generator.

• JavaTemplateSemanticallyEqual fails to match AssertJ's assertThat("foo").isEqualTo("") rewrite#4423