feat(runtime): introduce experimental.runtimeMode

[LingyuCoder]

Summary

Introduce experiments.runtimeMode as an experimental runtime rendering mode.

This PR adds the rspack runtime context path and updates runtime code generation so runtime globals can be rendered through __rspack_context in rspack mode while preserving the existing webpack-compatible runtime output by default.

Main changes:

• Add runtime proxy metadata collection for tree/module/runtime requirements.
• Render runtime context declarations, lexical runtime globals, and context field assignments for rspack mode.
• Generate execute-module runtime source using the same runtime module source rendering path.
• Teach parser runtime requirements and nested require/context handling about rspack runtime mode.
• Update chunk loading, CSS loading, HMR, library, and runtime module templates to use the new runtime context path only when rspack mode is enabled.
• Avoid forcing optional helpers such as SCRIPT_NONCE; nonce code is emitted only when the runtime requirement is actually present.
• Add runtime-mode focused config/hot test suites and snapshots.

[github-actions]

📦 Binary Size-limit

Comparing e867c35 to refactor: swc exp for javascript parser plugin (#14256) by CPunisher

❌ Size increased by 88.13KB from 62.60MB to 62.68MB (⬆️0.14%)

[github-actions]

Rsdoctor Bundle Diff Analysis

Found 5 projects in monorepo, 5 projects with changes.

📊 Quick Summary

Project	Total Size	Gzip Size	Change	Gzip Change
popular-libs	1.7 MB	551.3 KB	-3.0 B (-0.0%)	0
react-10k	5.6 MB	1.3 MB	-73.0 B (-0.0%)	-18.0 B (-0.0%)
react-1k	822.7 KB	218.2 KB	-73.0 B (-0.0%)	-21.0 B (-0.0%)
react-5k	2.7 MB	669.1 KB	-73.0 B (-0.0%)	-15.0 B (-0.0%)
ui-components	4.8 MB	1.4 MB	-3.0 B (-0.0%)	0

📋 Detailed Reports (Click to expand)

📁 popular-libs

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

📌 Baseline Commit: 1fd4fca45e | PR: #14256

Metric	Current	Baseline	Change
📊 Total Size	1.7 MB	1.7 MB	-3.0 B (-0.0%)
🗜️ Gzip Size	551.3 KB	551.3 KB	0
📄 JavaScript	1.7 MB	1.7 MB	-3.0 B (-0.0%)
🎨 CSS	0 B	0 B	0
🌐 HTML	289.0 B	289.0 B	0
📁 Other Assets	0 B	0 B	0

📦 Download Diff Report: popular-libs Bundle Diff

📁 react-10k

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

📌 Baseline Commit: 1fd4fca45e | PR: #14256

Metric	Current	Baseline	Change
📊 Total Size	5.6 MB	5.6 MB	-73.0 B (-0.0%)
🗜️ Gzip Size	1.3 MB	1.3 MB	-18.0 B (-0.0%)
📄 JavaScript	5.6 MB	5.6 MB	-73.0 B (-0.0%)
🎨 CSS	21.0 B	21.0 B	0
🌐 HTML	328.0 B	328.0 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: 1fd4fca45e | PR: #14256

Metric	Current	Baseline	Change
📊 Total Size	822.7 KB	822.8 KB	-73.0 B (-0.0%)
🗜️ Gzip Size	218.2 KB	218.3 KB	-21.0 B (-0.0%)
📄 JavaScript	822.4 KB	822.4 KB	-73.0 B (-0.0%)
🎨 CSS	0 B	0 B	0
🌐 HTML	328.0 B	328.0 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: 1fd4fca45e | PR: #14256

Metric	Current	Baseline	Change
📊 Total Size	2.7 MB	2.7 MB	-73.0 B (-0.0%)
🗜️ Gzip Size	669.1 KB	669.1 KB	-15.0 B (-0.0%)
📄 JavaScript	2.7 MB	2.7 MB	-73.0 B (-0.0%)
🎨 CSS	21.0 B	21.0 B	0
🌐 HTML	328.0 B	328.0 B	0
📁 Other Assets	0 B	0 B	0

📦 Download Diff Report: react-5k Bundle Diff

📁 ui-components

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

📌 Baseline Commit: 1fd4fca45e | PR: #14256

Metric	Current	Baseline	Change
📊 Total Size	4.8 MB	4.8 MB	-3.0 B (-0.0%)
🗜️ Gzip Size	1.4 MB	1.4 MB	0
📄 JavaScript	4.7 MB	4.7 MB	-3.0 B (-0.0%)
🎨 CSS	111.7 KB	111.7 KB	0
🌐 HTML	328.0 B	328.0 B	0
📁 Other Assets	0 B	0 B	0

📦 Download Diff Report: ui-components Bundle Diff

🤖 AI Degradation Analysis (Click to expand)

📁 popular-libs

📊 Size Changes

No significant regressions detected 🎉
(Total bundle: 1,806,629 → 1,806,626 bytes | Δ -0.00016%)

🔍 Root Cause Analysis

• No code changes detected: modules and packages arrays are empty (0 added, 0 removed, 0 changed).
• The negligible size difference (-3 bytes) is likely due to build timestamp or whitespace variations.

⚠️ Risk Assessment

Overall severity: Low

• Initial chunk size is effectively unchanged (1,806,340 → 1,806,337 bytes), posing no risk to load performance.

💡 Optimization Suggestions

1. Verify Commit Content: Confirm intended source code changes were included in this build, as the bundle is identical to baseline.
2. Maintain Standards: Continue current tree-shaking and code-splitting configurations; they are stable.
3. CI Thresholds: Ensure bundle size budgets allow for minor noise to prevent false positives in future checks.

_{Analysis by qwen3.5-plus}

📁 react-10k

📊 Size Changes

No significant regressions detected 🎉
Win: Total bundle size decreased by 73 bytes (5,861,109 → 5,861,036).

🔍 Root Cause Analysis

• No modules or packages were added, removed, or changed in the diff.
• The negligible size reduction (73 bytes) across all assets suggests build metadata or hash variation rather than code changes.

⚠️ Risk Assessment

Overall severity: Low

• Initial chunk size decreased slightly (745,709 → 745,636 bytes); zero negative impact on Time to Interactive.

💡 Optimization Suggestions

1. No immediate actions required; the bundle is stable.
2. Verify build reproducibility if exact byte-for-byte consistency is expected across CI runs.
3. Continue monitoring for actual module-level changes in future PRs.

_{Analysis by qwen3.5-plus}

📁 react-1k

📊 Size Changes

No significant regressions detected 🎉. Total bundle size decreased slightly (842,508 → 842,435 bytes).

🔍 Root Cause Analysis

• No modules or packages were added, removed, or changed in this diff.
• Minor size variance is attributed to build metadata or hashing differences.

⚠️ Risk Assessment

Overall severity: Low

• Initial chunk stable at 775,950 bytes (Δ -73 bytes); no impact on Time to Interactive.

💡 Optimization Suggestions

1. No immediate actions required; bundle health is stable.
2. Maintain current code-splitting strategy for future features.

_{Analysis by qwen3.5-plus}

📁 react-5k

📊 Size Changes

No significant regressions detected 🎉.
Win: Total bundle size decreased by 73 bytes (2,793,999 → 2,793,926). Initial JS also decreased slightly (525,088 → 525,015 bytes).

🔍 Root Cause Analysis

• No module or package changes detected in the diff data (modules.changed is empty).
• Variance likely attributed to build hash updates or negligible content shifts.

⚠️ Risk Assessment

Overall severity: Low

• Initial chunk size reduced by 73 bytes, ensuring no negative impact on Time to Interactive (TTI) or load performance.

💡 Optimization Suggestions

1. No immediate actions required; bundle health is stable.
2. Maintain current code-splitting and tree-shaking configurations.
3. Continue monitoring for deltas >10 KB in future PRs to catch regressions early.

_{Analysis by qwen3.5-plus}

📁 ui-components

📊 Size Changes

No significant regressions detected 🎉. Total bundle size slightly decreased from 5,079,179 bytes to 5,079,176 bytes (-3 bytes).

🔍 Root Cause Analysis

• No module or package changes detected in the diff (added/removed/changed lists are empty).
• JS initial chunk remained effectively stable (4,964,432 → 4,964,429 bytes).
• CSS assets unchanged at 114,419 bytes.

⚠️ Risk Assessment

Overall severity: Low

• Negligible total size delta (-0.00006%) with no impact on initial chunk load performance or asset count.

💡 Optimization Suggestions

1. No immediate action required; bundle health is stable.
2. Continue monitoring future diffs for new dependency additions that might impact the initial chunk.
3. Maintain current tree-shaking configurations as no bloat was introduced.

_{Analysis by qwen3.5-plus}

Generated by Rsdoctor GitHub Action

[codspeed-hq]

Merging this PR will improve performance by 11.64%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 2 improved benchmarks
❌ 1 regressed benchmark
✅ 49 untouched benchmarks
⏩ 40 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	rust@create_chunk_assets	3.2 ms	3.3 ms	-3.07%
⚡	WallTime	bundle@threejs-10x-development	308.7 ms	223.7 ms	+37.99%
⚡	Simulation	rust@persistent_cache_restore@basic-react-development	15.8 ms	15.2 ms	+4.02%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing codex/runtime-proxy-context-redesign (e867c35) with main (1fd4fca)}

Footnotes

1. 40 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[cloudflare-workers-and-pages]

Deploying rspack with    Cloudflare Pages

Latest commit:	55a76d8
Status:	✅  Deploy successful!
Preview URL:	https://ec6512e6.rspack-v2.pages.dev
Branch Preview URL:	https://codex-runtime-proxy-context.rspack-v2.pages.dev

View logs

[Copilot]

Copilot wasn't able to review this pull request because it exceeds the maximum number of files (300). Try reducing the number of changed files and requesting a review from Copilot again.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: e867c3553b

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Preserve trailing require member chains

When experiments.runtimeMode is 'rspack' and code reads a static chain beyond a known runtime global, such as __webpack_require__.g.document or __webpack_require__.m.foo, members.first() only maps the first property but this call passes the full member_expr.span, so the dependency replaces the entire chain with __rspack_context.g/.m and drops the trailing property. This changes the generated code for those inputs; use the member ranges to replace only the __webpack_require__.<prop> prefix or bail out when there are additional members.

Useful? React with 👍 / 👎.