fix(cli): honor externalHelpers=false in rust binary by kdy1 · Pull Request #11693 · swc-project/swc

kdy1 · 2026-03-16T14:31:56Z

Summary

Enable inline helper support in the Rust CLI build by adding swc_core/ecma_helpers_inline to swc_cli_impl.
Fix behavior where jsc.externalHelpers: false was ignored and @swc/helpers was still emitted.
Add a regression test for issue externalHelpers broken in published rust binary #11643.

Changes

crates/swc_cli_impl/Cargo.toml
- Add ecma_helpers_inline to the swc_core feature list.
crates/swc_cli_impl/tests/issues.rs
- Add issue_11643_external_helpers_false_respected.
- Verify output does not reference @swc/helpers.
- Verify inline _export_star helper is emitted.

Verification

git submodule update --init --recursive
cargo test -p swc_cli_impl issue_11643
cargo test -p swc_cli_impl
cargo fmt --all
cargo clippy --all --all-targets -- -D warnings

Closes #11643

changeset-bot · 2026-03-16T14:32:12Z

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Latest commit: aa93151

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socket-security · 2026-03-16T14:32:48Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	glob@8.1.0
	eslint-define-config@1.24.1
	eslint@8.57.0
	dprint@0.35.4
	jest@29.7.0
	expect@27.5.1
	npm-run-all@4.1.5
	sourcemap-validator@2.1.0
	react@17.0.2
	husky@7.0.4
	regenerator-runtime@0.13.11
	reflect-metadata@0.1.14
	@types/node@20.12.12
	swc-plugin-coverage-instrument@0.0.26
	js-beautify@1.14.7
	ts-node@10.9.1
	prop-types@15.8.1
	source-map-support@0.5.21
	tsx@3.14.0
	yaml@2.4.5
	octokit@3.2.1
	zx@8.1.4
	webpack-dev-server@3.11.3
	source-map@0.7.4
	terser@5.17.6
	semver@7.6.2 ⏵ 7.5.4
	eslint-plugin-n@16.6.2
	typescript@5.5.4
	typescript@5.3.3
	webpack-cli@3.3.12
	prettier@2.8.8
	cspell@5.21.2
	mocha@9.2.2
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socket-security · 2026-03-16T14:32:50Z

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Review the following alerts detected in dependencies.

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Action	Severity	Alert (click "▶" to expand/collapse)
Warn		Obfuscated code: npm `js-beautify` is 100.0% likely obfuscated Confidence: 1.00 Location: Package overview From: package.json → `npm/js-beautify@1.14.7` ℹ Read more on: This package \| This alert \| What is obfuscated code? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at `support@socket.dev`. Suggestion: Packages should not obfuscate their code. Consider not using packages with obfuscated code. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment `@SocketSecurity ignore npm/js-beautify@1.14.7`. You can also ignore all packages with `@SocketSecurity ignore-all`. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.

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Pull request overview

Fixes the Rust swc CLI binary so that jsc.externalHelpers: false is honored by enabling inline helper emission, aligning behavior with @swc/cli / @swc/core and preventing unwanted @swc/helpers requires.

Changes:

Enable inline ECMA helpers in the Rust CLI build by adding the swc_core/ecma_helpers_inline feature.
Add a regression test covering issue #11643, asserting no @swc/helpers reference and presence of an inline _export_star helper.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
crates/swc_cli_impl/Cargo.toml	Enables inline helper support in the CLI build via `ecma_helpers_inline`.
crates/swc_cli_impl/tests/issues.rs	Adds a regression test ensuring `externalHelpers: false` no longer emits `@swc/helpers`.

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+        "Expected inline _export_star helper when externalHelpers is false. Got: {output}",
+    );
+    assert!(
+        output.contains("_export_star(require(\"./my-file\"), exports);"),


github-actions · 2026-03-16T14:41:02Z

Binary Sizes

File	Size
`swc.linux-x64-gnu.node`	28M (28752968 bytes)

Commit: f8b1bee

codspeed-hq · 2026-03-16T14:48:35Z

Merging this PR will not alter performance

✅ 219 untouched benchmarks

_{Comparing kdy1/fix-11643-external-helpers-cli (aa93151) with main (588577c)}

claude · 2026-03-16T14:53:19Z

PR Review: fix(cli): honor externalHelpers=false in rust binary

Summary

Clean, minimal fix. The root cause is that swc_cli_impl was missing the ecma_helpers_inline feature on swc_core, so inline helper injection was never compiled in for the Rust CLI binary. Without it, externalHelpers: false was silently ignored and @swc/helpers imports were emitted regardless.

Code Quality

Looks good. The fix is a single feature flag addition in Cargo.toml — exactly the right scope for this kind of bug. No unnecessary changes.

The test is well-structured and follows the existing patterns in issues.rs:

Creates a temp sandbox with a .swcrc and input files
Runs the CLI binary
Asserts on the output content with clear error messages

The three assertions cover the important invariants:

No @swc/helpers references (the bug)
Inline _export_star function is present (the fix)
The re-export call uses the inline helper (correctness)

Minor Observations

my-file.ts isn't strictly needed — the test only compiles index.ts and checks the output of that single file. However, having it present makes the test more realistic since export * from "./my-file" would be a real module graph, so this is fine.
The test asserts a specific function name (_export_star) and call pattern. This is slightly brittle if the helper naming ever changes, but it's consistent with how other tests in this file work, and the alternative (only checking absence of @swc/helpers) would be a weaker test. Good tradeoff.

Verdict

LGTM. Minimal, correct fix with good regression test coverage. The changeset is properly included.

fix(cli): honor externalHelpers false in rust binary

416517d

kdy1 marked this pull request as ready for review March 16, 2026 14:35

kdy1 requested a review from a team as a code owner March 16, 2026 14:35

Copilot AI review requested due to automatic review settings March 16, 2026 14:35

kdy1 enabled auto-merge (squash) March 16, 2026 14:35

kodiakhq Bot previously approved these changes Mar 16, 2026

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Comment thread crates/swc_cli_impl/tests/issues.rs

"Expected inline _export_star helper when externalHelpers is false. Got: {output}",

);

assert!(

output.contains("_export_star(require(\"./my-file\"), exports);"),

Create grumpy-badgers-itch.md

aa93151

kdy1 dismissed kodiakhq[bot]’s stale review via aa93151 March 16, 2026 14:51

kodiakhq Bot approved these changes Mar 16, 2026

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kdy1 disabled auto-merge March 16, 2026 15:08

kdy1 merged commit 1be052e into main Mar 16, 2026
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kdy1 deleted the kdy1/fix-11643-external-helpers-cli branch March 16, 2026 15:09

github-actions Bot modified the milestones: Planned, 1.15.21 Mar 16, 2026

swc-project locked as resolved and limited conversation to collaborators Apr 22, 2026

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fix(cli): honor externalHelpers=false in rust binary#11693

fix(cli): honor externalHelpers=false in rust binary#11693
kdy1 merged 2 commits intomainfrom
kdy1/fix-11643-external-helpers-cli

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Pull request overview

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Merging this PR will not alter performance

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claude Bot commented Mar 16, 2026

PR Review: fix(cli): honor externalHelpers=false in rust binary

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