pyrefly

Motivation: Currently, when you are working with a list comprehension like , the "Go to Definition" feature works for the variable after the for (the target ), but it fails and returns nothing if you try it on the variable before the for (the usage ). This PR fixes that bug so that clicking on the usage will correctly take you to where it is defined. Approach: The bug happens because of how the Pyrefly language server tries to follow the chain of variable references. For variables inside comprehensions, the chain goes through a special step called . The code that searches for definitions (find_definition_key_from in pyrefly/lib/state/ide.rs) did not know how to handle this step, so it would give up and return nothing. I updated the code to recognize as a valid stopping point. Now, when the search hits this point, it correctly returns the location of the variable. Tests: I added two tests in pyrefly/lib/test/lsp/definition.rs to make sure "Go to Definition" works for both parts of a list comprehension and to prevent this bug from coming back. I manually analyzed code bases and tested all the changes to make sure everything works correctly. Tests Screenshots

Summary: Fix two related issues with enum pattern matching: 1. Issues #2080 and #2604: was not handled alongside in narrowing, subset checking, and overload expansion. This caused false-positive "non-exhaustive match" errors when matching on inside enum methods, and incorrect return types. 2. Circular dependency bug: resolved ALL class fields (including methods), creating a cycle when called during method body analysis of enum methods using . Added a flag to so that can skip methods and nested classes without resolving their types. Fixes https://github.com/facebook/pyrefly/issues/2080 Fixes https://github.com/facebook/pyrefly/issues/2604 Differential Revision: D95437784