feat!: remove experiments.outputModule config by JSerFeng · Pull Request #12912 · web-infra-dev/rspack

JSerFeng · 2026-02-02T10:16:26Z

Summary

Remove experimental.outputModule.

Now you only need to set output.module to true if you want esm for app.

If you are building a library, when seting library.type to 'module' | 'modern-module', output.module, Rspack will set output.module to true automatically

export default {
  output: {
    module: true
  }
}

Checklist

Tests updated (or not required).
Documentation updated (or not required).

github-actions · 2026-02-02T10:24:10Z

Rsdoctor Bundle Diff Analysis

Found 5 projects in monorepo, 5 projects with changes.

📊 Quick Summary

Project	Total Size	Change
react-10k	5.7 MB	+11.0 B (0.0%)
react-1k	825.4 KB	+11.0 B (0.0%)
react-5k	2.7 MB	+11.0 B (0.0%)
rome	984.2 KB	+8.0 B (0.0%)
ui-components	2.2 MB	+67.0 B (0.0%)

📋 Detailed Reports (Click to expand)

📁 react-10k

Path: ../build-tools-performance/cases/react-10k/dist/rsdoctor-data.json

📌 Baseline Commit: 758f6227be | PR: #12782

Metric	Current	Baseline	Change
📊 Total Size	5.7 MB	5.7 MB	+11.0 B (0.0%)
📄 JavaScript	5.7 MB	5.7 MB	+11.0 B (0.0%)
🎨 CSS	21.0 B	21.0 B	0
🌐 HTML	0 B	0 B	0
📁 Other Assets	0 B	0 B	0

📦 Download Diff Report: react-10k Bundle Diff

📁 react-1k

Path: ../build-tools-performance/cases/react-1k/dist/rsdoctor-data.json

📌 Baseline Commit: 758f6227be | PR: #12782

Metric	Current	Baseline	Change
📊 Total Size	825.4 KB	825.4 KB	+11.0 B (0.0%)
📄 JavaScript	825.4 KB	825.4 KB	+11.0 B (0.0%)
🎨 CSS	0 B	0 B	0
🌐 HTML	0 B	0 B	0
📁 Other Assets	0 B	0 B	0

📦 Download Diff Report: react-1k Bundle Diff

📁 react-5k

Path: ../build-tools-performance/cases/react-5k/dist/rsdoctor-data.json

📌 Baseline Commit: 758f6227be | PR: #12782

Metric	Current	Baseline	Change
📊 Total Size	2.7 MB	2.7 MB	+11.0 B (0.0%)
📄 JavaScript	2.7 MB	2.7 MB	+11.0 B (0.0%)
🎨 CSS	21.0 B	21.0 B	0
🌐 HTML	0 B	0 B	0
📁 Other Assets	0 B	0 B	0

📦 Download Diff Report: react-5k Bundle Diff

📁 rome

Path: ../build-tools-performance/cases/rome/dist/rsdoctor-data.json

📌 Baseline Commit: 758f6227be | PR: #12782

Metric	Current	Baseline	Change
📊 Total Size	984.2 KB	984.2 KB	+8.0 B (0.0%)
📄 JavaScript	984.2 KB	984.2 KB	+8.0 B (0.0%)
🎨 CSS	0 B	0 B	0
🌐 HTML	0 B	0 B	0
📁 Other Assets	0 B	0 B	0

📦 Download Diff Report: rome Bundle Diff

📁 ui-components

Path: ../build-tools-performance/cases/ui-components/dist/rsdoctor-data.json

📌 Baseline Commit: 758f6227be | PR: #12782

Metric	Current	Baseline	Change
📊 Total Size	2.2 MB	2.2 MB	+67.0 B (0.0%)
📄 JavaScript	2.0 MB	2.0 MB	+67.0 B (0.0%)
🎨 CSS	267.8 KB	267.8 KB	0
🌐 HTML	0 B	0 B	0
📁 Other Assets	0 B	0 B	0

📦 Download Diff Report: ui-components Bundle Diff

Generated by Rsdoctor GitHub Action

github-actions · 2026-02-02T10:26:24Z

📦 Binary Size-limit

Comparing 2747fab to chore: gracefully explain unsupported interfaces (#12782) by Martin Jesper Low Madsen

🙈 Size remains the same at 48.33MB

codspeed-hq · 2026-02-02T10:34:03Z

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing refactor/remove-experiments-outputModule (2747fab) with main (758f622)}

Summary

✅ 16 untouched benchmarks
⏩ 1 skipped benchmark¹

1 benchmark was skipped, so the baseline result was used instead. If it was deleted from the codebase, click here and archive it to remove it from the performance reports. ↩

crates/rspack/src/builder/mod.rs

tests/rspack-test/configCases/target/universal/rspack.config.js

.../rspack-test/serialCases/container-1-5/4-async-startup-runtime-chunk-single/rspack.config.js

website/docs/zh/config/experiments.mdx

cloudflare-workers-and-pages · 2026-02-03T06:04:57Z

Deploying rspack with Cloudflare Pages

Latest commit:	`2747fab`
Status:	✅ Deploy successful!
Preview URL:	https://84db3d05.rspack-v2.pages.dev
Branch Preview URL:	https://refactor-remove-experiments.rspack-v2.pages.dev

View logs

Copilot

Pull request overview

This pull request refactors the configuration for ESM module output by removing the experimental experiments.outputModule flag and promoting output.module as the standard configuration option.

Changes:

Removed experiments.outputModule from type definitions, normalization logic, and default configuration
Updated all test configurations to use output.module instead of experiments.outputModule
Modified defaults logic to automatically set output.module to true when library.type is 'module' or 'modern-module'
Updated documentation in both English and Chinese to reflect the new configuration approach

Reviewed changes

Copilot reviewed 161 out of 161 changed files in this pull request and generated 17 comments.

Show a summary per file

File	Description
website/docs/zh/guide/features/esm.mdx	Removed outdated reference to experiments.outputModule in Chinese documentation
website/docs/zh/config/output.mdx	Updated Chinese documentation but contains outdated code examples
website/docs/zh/config/externals.mdx	Updated Chinese documentation to reference output.module
website/docs/zh/config/experiments.mdx	Removed experiments.outputModule section from Chinese documentation
website/docs/en/guide/features/esm.mdx	Removed outdated reference to experiments.outputModule
website/docs/en/config/output.mdx	Updated to remove experimental flag requirement and added automatic behavior description
website/docs/en/config/externals.mdx	Updated to reference output.module instead of experiments.outputModule
website/docs/en/config/experiments.mdx	Removed experiments.outputModule section
tests/rspack-test/*/.js	Migrated 100+ test configurations from experiments.outputModule to output.module, with some containing duplicates
packages/rspack/src/config/types.ts	Removed outputModule from Experiments type definition
packages/rspack/src/config/normalization.ts	Removed outputModule from ExperimentsNormalized interface
packages/rspack/src/config/defaults.ts	Refactored to set output.module based on library types, but has ordering issue
packages/rspack/etc/core.api.md	Updated API documentation to remove experiments.outputModule
packages/rspack-test-tools/src/case/*.ts	Updated test tooling to use output.module
crates/rspack/src/builder/mod.rs	Removed outputModule from Rust builder implementation

Comments suppressed due to low confidence (1)

website/docs/zh/config/output.mdx:1577

The code example still includes the removed experiments.outputModule configuration. This should be removed to match the English documentation and align with the PR's refactoring. The example should only show output.module: true without any experimental flags.

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

tests/rspack-test/configCases/node/filename-and-dirname/rspack.config.js

tests/rspack-test/configCases/module/non-webpack-require-warning/rspack.config.js

tests/rspack-test/configCases/library/modern-module-asset-entry/rspack.config.js

website/docs/zh/config/output.mdx

tests/rspack-test/configCases/node/filename-and-dirname/rspack.config.js

tests/rspack-test/configCases/externals/devtool-eval-concatenate-modules/rspack.config.js

tests/rspack-test/configCases/library/modern-module-dynamic-error/rspack.config.js

tests/rspack-test/configCases/node/filename-and-dirname/rspack.config.js

tests/rspack-test/configCases/asset-modules/entry-with-runtimeChunk/rspack.config.js

tests/rspack-test/configCases/library/module-terminal-binding/rspack.config.js

chenjiahan

👍

refactor: remove experiments.outputModule

be7cb68

JSerFeng requested review from LingyuCoder, h-a-n-a and hardfist as code owners February 2, 2026 10:16

Copilot AI review requested due to automatic review settings February 2, 2026 10:16

github-actions bot added release: refactor team The issue/pr is created by the member of Rspack. labels Feb 2, 2026

JSerFeng requested review from chenjiahan and removed request for LingyuCoder, Copilot, h-a-n-a and hardfist February 2, 2026 10:16

Copilot started reviewing on behalf of JSerFeng February 2, 2026 10:16 View session

chenjiahan reviewed Feb 2, 2026

View reviewed changes

fix: remove needless docs and fix some styles in config

25422a9

Copilot AI review requested due to automatic review settings February 3, 2026 06:03

Copilot started reviewing on behalf of JSerFeng February 3, 2026 06:05 View session

Copilot AI reviewed Feb 3, 2026

View reviewed changes

chenjiahan previously approved these changes Feb 3, 2026

View reviewed changes

chenjiahan changed the title ~~refactor: remove experiments.outputModule~~ feat!: remove experiments.outputModule config Feb 3, 2026

github-actions bot added release: feature release: feature related release(mr only) and removed release: refactor labels Feb 3, 2026

JSerFeng enabled auto-merge (squash) February 3, 2026 06:24

JSerFeng dismissed chenjiahan’s stale review via f23d3fb February 3, 2026 06:32

fix: correct some configs

2747fab

JSerFeng force-pushed the refactor/remove-experiments-outputModule branch from f23d3fb to 2747fab Compare February 3, 2026 07:06

LingyuCoder approved these changes Feb 3, 2026

View reviewed changes

JSerFeng merged commit f3ddd72 into main Feb 3, 2026
97 of 104 checks passed

JSerFeng deleted the refactor/remove-experiments-outputModule branch February 3, 2026 07:58

This was referenced Feb 3, 2026

feat(deps): upgrade @rspack/core to 2.0.0-beta.0 web-infra-dev/rsbuild#7134

Merged

docs: remove experimental outputModule configuration #12952

Merged

Uh oh!

Comments

Conversation

JSerFeng commented Feb 2, 2026

Summary

Related links

Checklist

Uh oh!

github-actions bot commented Feb 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Rsdoctor Bundle Diff Analysis

📁 react-10k

📁 react-1k

📁 react-5k

📁 rome

📁 ui-components

Uh oh!

github-actions bot commented Feb 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

📦 Binary Size-limit

Uh oh!

codspeed-hq bot commented Feb 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

CodSpeed Performance Report

Merging this PR will not alter performance

Summary

Footnotes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

cloudflare-workers-and-pages bot commented Feb 3, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Deploying rspack with Cloudflare Pages

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

chenjiahan left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

github-actions bot commented Feb 2, 2026 •

edited

Loading

github-actions bot commented Feb 2, 2026 •

edited

Loading

codspeed-hq bot commented Feb 2, 2026 •

edited

Loading

cloudflare-workers-and-pages bot commented Feb 3, 2026 •

edited

Loading