GV

GeezerVison

The World Wide Web, restored to 800 pixels of glory.

Home|About|Gaming cabinet|Archives|How it works|Starter sites

On this site

  • Sign in
  • ActionsCI/CD and automation
  • CodespacesCloud development environments
  • All Features
  • Documentation
  • Training
  • Certifications
  • Build with Copilot
  • Customize Copilot
  • Integrations
  • Trending repos
  • GitHub Sponsors
  • Developer articles
  • Enterprises

This view

  • Original page
  • New address

GeezerVison is showing github.com — fix sync try/catch re-throw and return handling by pilaoda · Pull Request #1726 · TypeScriptToLua/TypeScriptToLua

Conversation

@pilaoda

@pilaoda pilaoda commented May 28, 2026

Copy link
Copy Markdown
Contributor

Summary

The previous sync try/catch implementation had a fundamental issue: the catch block was not wrapped in pcall, so if catch itself threw an error, it would bypass the finally block and propagate as an unhandled Lua error instead of being re-thrown after finally completes — diverging from JavaScript semantics.

Fixing this required rewriting the sync transformTryStatement to:

  • Always capture 3 return values (____trySuccess, ____hasReturnOrError, ____returnValue) from pcall
  • Wrap the catch block in its own pcall so catch errors are captured
  • Use if ____trySuccess / elseif ____catchSuccess / else error() post-finally decision structure

This unified architecture also simplifies adding break/continue support inside try/catch (see follow-up PR).

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.

All reactions
@pilaoda
(transformation): rewrite try-catch-finally implementation to correct…
7579194
…ly handle returns and re-throws

(test):
- enable previously skipped re-throw tests
- add tests for complex try-catch-finally return and throw scenarios
Copilot AI review requested due to automatic review settings May 28, 2026 13:33
@pilaoda pilaoda mentioned this pull request May 28, 2026
fix break and continue inside sync try/catch blocks #1727
Open
pilaoda and others added 3 commits May 28, 2026 21:48
@pilaoda @claude
(test): handle non-Error thrown values in executeJs
9670111
Co-Authored-By: Claude Opus 4.6 <[email protected]>
@pilaoda @claude
(transformation): rename catchPcall to catchCall for consistency with…
b843c09
… tryCall

Co-Authored-By: Claude Opus 4.6 <[email protected]>
@pilaoda @claude
refactor: extract helper and clarify elseBranch logic in sync try-catch
812abde
Extract duplicated return-if-has-return-or-error into a module-level
helper. Expand the elseBranch ternary into an explicit if/else with
comments for each case (non-empty catch, no catch, empty catch).

Co-Authored-By: Claude Opus 4.6 <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

Copilot code review Copilot Reviewing

Uh oh!

There was an error while loading. Please reload this page.

Assignees

No one assigned

Labels

None yet

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

Uh oh!

There was an error while loading. Please reload this page.

1 participant

@pilaoda
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
You are visitor 01402520 — GeezerVison does not store the pages you look up.
Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.