fix: stop Rails Routes from stalling on cast errors and unsaved files

[thinkAmi]

Background

GitHub issue #94 reports that clicking Rails Routes on RubyMine 2026.1.1 stalls at Loading... and logs ClassCastException: RConstantImpl cannot be cast to RContainer. Routes parsing aborts entirely when Ruby's StubIndex returns a non-RContainer element (for example a constant referenced by include) for a name that the existing code cast unconditionally.

While addressing that, an adjacent issue is also fixed: when the user edits config/routes.rb and clicks Rails Routes without saving, the external rails routes process reads the on-disk file and ignores the in-editor changes.

Summary

• Skip non-RContainer StubIndex results so Rails Routes no longer stalls on the reported cast error.
• Save unsaved editor buffers before running rails routes, so the command sees the latest route edits.

Changes

• PsiUtil.findClassOrModule() now requires an is RContainer smart cast in addition to the name match. Non-RContainer entries from the StubIndex (such as RConstantImpl) are skipped, and null is returned when no class/module is found. The three existing call sites already tolerate null / non-matching containers.
• RailsRouteAction.actionPerformed() calls FileDocumentManager.getInstance().saveAllDocuments() at the action entry point before launching the routes task. The save is intentionally placed in the action (EDT, write-safe context) rather than inside RoutesTask / RoutesPreflight, which run inside coroutine read actions and external-process IO contexts not suited for write commands.

Notes

• No new unit test for PsiUtil.findClassOrModule() is included. A BasePlatformTestCase attempt failed in setUp because Ruby plugin's BundleConfigService.getInstance() returns null on the Light Test Fixture, which blocks creation of *.rb PSI files. Setting up a Ruby-aware test fixture is tracked separately as a follow-up so the regression test can be added later.
• The scope is intentionally limited to the action entry point and the StubIndex result handling. Broader cleanup of the routes parsing pipeline is not part of this PR.

Testing

• ./gradlew check
• Manual: verified on the reporter's routes.rb (including Module.new-style routing) that Rails Routes no longer throws ClassCastException and the routes table loads. Also verified that editing config/routes.rb without saving and then clicking Rails Routes reflects the latest changes.
  • After applying the fixes from the following pull request to the Rails application used for functionality testing.
    • feat: add routes (include controller) thinkAmi-sandbox/rails_large_routes_app#3