fix(es/compat): Fix generator transform for compound assignments, for-in, and labeled break

[magic-akari]

Description:

BREAKING CHANGE:

Related issue (if exists):

• Closes RangeError: Maximum call stack size exceeded #5433
• Closes ES5 generator transform produces extra function values when yielding nested object #11046
• Closes ES5 destructuring transform drops array hole and shifts default value assignment #11047
• Closes Default values in async function array destructuring miscompiled in ES5 target #11048
• Closes ES5 async array destructuring awaited value replaced with pending Promise #11049
• Closes ES5 async short-circuit assignment and labeled break miscompiled causing wrong control flow #11050
• Closes ES5 async method transform drops write-back for compound assignment to this property across await #11052

[changeset-bot]

🦋 Changeset detected

Latest commit: 51ca02a

The changes in this PR will be included in the next version bump.

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

Binary Sizes

File	Size
swc.linux-x64-gnu.node	31M (31873608 bytes)

Commit: f0d9ac3

[codspeed-hq]

CodSpeed Performance Report

Merging #11339 will not alter performance

_{Comparing magic-akari:fix/generator (51ca02a) with main (b6ad2cb)}

Summary

✅ 138 untouched

[Copilot]

Pull request overview

This PR fixes critical bugs in the ES2015 generator transform for compound assignments, for-in loops, and labeled break statements. The changes ensure proper code generation when these constructs are used with generators and async functions that are compiled to ES5.

Key changes:

• Fixed compound assignments with yield expressions to properly cache the left-hand side value before evaluation
• Enhanced for-in loop transformation to handle property deletion during iteration
• Corrected labeled break statement resolution to only match LabeledBlocks

Reviewed changes

Copilot reviewed 57 out of 57 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/swc_ecma_compat_es2015/src/generator.rs	Core fix for compound assignments, for-in loops, and labeled break handling
crates/swc_ecma_transforms_base/src/helpers/_ts_generator.js	Updated generator helper to use Object.defineProperty for better compatibility
packages/helpers/esm/_ts_generator.js	Forked version of _ts_generator helper with Object.defineProperty
packages/helpers/scripts/ast_grep.js	Updated build script to exclude forked _ts_generator from tslib import rewriting
packages/helpers/.dprint.json	Excluded _ts_generator files from formatting
Multiple test files	Added comprehensive test cases for all fixed issues

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[kdy1]

Wow... I'll review your PRs after the trip. Sorry for the delay.