What's the best way to approach this?

I got it working by trying some basic checks in
public Description matchMethod(MethodTree tree, VisitorState state) which is here

Very hacky code:

AnnotationTree tat =
            ASTHelpers.getAnnotationWithSimpleName(tree.getModifiers().getAnnotations(), "Test");
    if (tat != null) {
      // easymock - most common is andReturn - add more to list but have to be 100% sure
      if (tree.getBody().toString().contains("expect(true).andReturn") || tree.getBody().toString().contains("expect(false).andReturn")) {
        Description.Builder builder = buildDescription(tree);
        SuggestedFix.Builder fixBuilder = SuggestedFix.builder();
        List<? extends StatementTree> statements = tree.getBody().getStatements();
        for (StatementTree statement : statements) {
          if (isSimplifiedTestStatement(statement.toString())) {
            fixBuilder.delete(statement);
            builder.addFix(fixBuilder.build());
            return builder.build();
//            decrementAllSymbolUsages(tree, state, fixBuilder);
          }
        }
}

where isSimplifiedTestStatement just does more string matching.

Not sure if adding this logic to matchMethod would work, maybe we need to run piranha twice or modify the code to increase no. of passes.

Can you post the input code and expected output code? I think updating the methodProperties for these methods should handle this issue too.

Basically, delete the lines which are test related calls, where Piranha has already visited and substituted with a boolean

Original code

@Test
    public void testToggle() {
        ...
        int a = 1;
        expect(mockToggle.isToggleEnabled()).andReturn(true).anyTimes();
        int b = a + 1;
        ...
        assertFalse(mockToggle.isToggleEnabled());
    }

Piranha modified code

@Test
    public void testToggle() {
        ...
        int a = 1;
        expect(true).andReturn(true).anyTimes();
        int b = a + 1;
        ...
        assertFalse(true); // causes test to fail
    }

Expected code:

@Test
    public void testToggle() {
        ...
        int a = 1;
        int b = a + 1;
        ...
    }

This may be a slightly involved fix and it is better to avoid special casing. We will need to implement multi-pass analysis on the code to get this correct.

1. In the first pass, determine the various Piranha refactorings and their locations, but do no rewrite the code.
2. In the second pass, use the information from the previous pass along with standard Piranha refactoring to rewrite.

For the second pass to succeed in the case given above, methods expect, andReturn and anyTimes can be given as empty methodTypes as part of methodProperties.

Another option is to determine the code range that is updated by Piranha and re-run the standard Piranha analysis and restrict the refactorings to those regions.

Let us discuss more on the gitter channel before finalizing a solution.

This has been resolved in #156.