[PerryLink]

What

Modules whose names use Windows path separators are silently dropped from the report.

// src/tree/utils.js:23-31
const parts = module.name.split('/')     // a name like "C:\\repo\\src\\x.js" yields one part
return parts.slice(1)                    // ... and slice(1) is empty -> null

Folder.addModule() (src/tree/Folder.js:79-83) then returns without a warning, so the module is
missing from the treemap and the JSON report, and statSize (src/analyzer.js:546) is under-counted.
The same happens to inner modules of a concatenated module (src/tree/ConcatenatedModule.js:80-84).

Reachable in practice: webpack writes an absolute path into module.name when the module lives on a
different drive than the project (webpack/lib/util/identifier.js, absoluteToRequest() returns the
absolute path when path.win32.relative() still produces one). A real webpack 5 build with the project
on D: and a module on C: produced 140 bytes of modules but statSize = 102, with cross.js absent
from the report.

The change

-  const parts = module.name.split('/')
+  const parts = module.name.split(/[\\/]/u)

One expression, slice(1) semantics unchanged, and identical results for every name that only uses /
(the existing fixtures are compared before/after and are byte-identical).

A changeset (.changeset/windows-path-module-names.md) is included, as the repository requires.

Verification

• unit test added to test/analyzerUtils.js: 1 failed, 12 passed before (./shared/lib/util.js missing
  from the parsed path array), 13 passed after;
• the real webpack 5 build above: statSize 102 → 140 and cross.js reappears;
• the 8 existing expected-chart-data fixtures produce identical getViewerData() output before and
  after (including with-module-concatenation-info and the gzip column);
• 5 non-puppeteer suites / 113 tests pass; eslint, prettier --check, tsc --noEmit clean;
• git apply (with core.autocrlf=false) on a pristine tarball reproduces files/ byte-for-byte.

The new test is a pure string assertion with no path.sep or platform constants, so it behaves the same
on the ubuntu × Node 20/22/24 CI matrix.

The puppeteer-backed suites cannot run on this machine (no Chrome); their fixtures were compared through
getViewerData() instead, as described above.

Summary by CodeRabbit

• Bug Fixes
  • Module paths using Windows separators now appear correctly in bundle analyzer reports, including paths resolved across drives.
  • Drive-qualified paths are normalized in the report while preserving bundle size totals.

[changeset-bot]

🦋 Changeset detected

Latest commit: 4e3015b

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

This PR includes changesets to release 1 package

Name	Type
webpack-bundle-analyzer	Patch

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

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: PerryLink / name: PerryLink (4e3015b)

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Organization UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 72d0e578-dcf6-42eb-851b-f0cd4da22edb

📥 Commits

Reviewing files that changed from the base of the PR and between 0ebe1e5 and 4e3015b.

📒 Files selected for processing: 3

• .changeset/windows-path-module-names.md
• src/tree/utils.js
• test/analyzerUtils.js

Included review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 9 remain after this review.

Walkthrough

Module path parsing now recognizes both forward and backslash separators. A new test checks that a Windows drive-qualified module name is reported as ./shared/lib/util.js, alongside ./src/index.js, and that the bundle stat size remains 150. A patch changeset records this change.

Priority: ⬇️ Low

Merge Risk: ⚪ Minimal · up to 4e301

Windows-style module paths are now included in reports and contribute to bundle sizes. No established issue warrants delaying the change.

Pre-merge checks: 5

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main change: splitting module paths on both slash types to prevent Windows modules from being dropped.
Docstring Coverage		Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files. (1 skipped: 1 …
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files. (1 skipped: 1 unsupported.)

✨ Finishing Touches: 💡 1

🛠️ Fix failing CI checks: 💡

• Commit to this branch
• Create a new PR

🧪 Generate unit tests (beta)

• Create a new PR

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

Warning

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🔧 ESLint

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test/analyzerUtils.js

ESLint skipped: missing config or dependency (missing-dependency). The ESLint configuration references a package that is not available in the sandbox.

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