fix: use jsdelivr when npm has a truncated readme by lukeocodes · Pull Request #1459 · npmx-dev/npmx.dev

lukeocodes · 2026-02-13T08:09:31Z

Summary

Large READMEs are being cut off because the npm registry silently truncates the readme field in packument responses at exactly 65,536 characters. For example, vue-data-ui has an 80KB README but only 64K makes it through.

This switches the README handler to fetch the actual file from jsDelivr CDN (which serves from the npm tarball without truncation) as the primary source, keeping the packument readme field as a fallback for packages where jsDelivr doesn't have the file.

Closes #1458

Test plan

Verified locally with vue-data-ui — full README now renders
Spot check other packages with large READMEs
Confirm packages with non-standard readme filenames still render correctly (fallback to packument)

vercel · 2026-02-13T08:09:37Z

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coderabbitai · 2026-02-13T08:16:20Z

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📝 Walkthrough

Walkthrough

The PR computes a resolvedVersion (from an explicit version or dist-tag) and adopts a jsDelivr-first strategy to fetch README content for that resolvedVersion (pkg@version). It removes reliance on version-specific readme fields and readmeFilename from the npm packument. If jsDelivr yields no content, it falls back to the packument readme — preferring the versioned packument readme when a specific version was requested, otherwise the top-level packument readme — and excludes sentinel missing values. If no readmeContent is obtained, it returns the packageName, version, and undefined markdown/repoInfo.

Possibly related PRs

perf: load markdown source code on copy instead of on main request #1386: Modifies the same README loading and resolution code paths, introducing/adjusting jsDelivr-first fetching and packument fallback logic.

Suggested reviewers

danielroe

🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Merge Conflict Detection	⚠️ Warning	❌ Merge conflicts detected (22 files): ⚔️ `app/app.vue` (content) ⚔️ `app/components/AppFooter.vue` (content) ⚔️ `app/components/AppHeader.vue` (content) ⚔️ `app/components/Link/Base.vue` (content) ⚔️ `app/components/Package/TrendsChart.vue` (content) ⚔️ `app/components/Package/VersionDistribution.vue` (content) ⚔️ `app/components/Package/Versions.vue` (content) ⚔️ `app/utils/versions.ts` (content) ⚔️ `i18n/locales/en.json` (content) ⚔️ `i18n/locales/fr-FR.json` (content) ⚔️ `i18n/schema.json` (content) ⚔️ `lunaria/files/en-GB.json` (content) ⚔️ `lunaria/files/en-US.json` (content) ⚔️ `lunaria/files/fr-FR.json` (content) ⚔️ `package.json` (content) ⚔️ `pnpm-lock.yaml` (content) ⚔️ `server/utils/readme-loaders.ts` (content) ⚔️ `shared/utils/constants.ts` (content) ⚔️ `test/nuxt/components/PackageVersions.spec.ts` (content) ⚔️ `test/unit/app/utils/versions.spec.ts` (content) ⚔️ `test/unit/server/utils/readme-loaders.spec.ts` (content) ⚔️ `test/unit/shared/utils/package-analysis.spec.ts` (content) These conflicts must be resolved before merging into `main`.	Resolve conflicts locally and push changes to this branch.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description check	✅ Passed	The pull request description clearly explains the problem (npm truncation at 65,536 chars), the solution (jsDelivr-first approach), and includes test verification.
Linked Issues check	✅ Passed	The pull request implementation aligns with issue `#1458` requirements: it prioritises jsDelivr CDN for README fetching and maintains packument fallback for non-standard filenames.
Out of Scope Changes check	✅ Passed	All changes are focused on the README loading mechanism to resolve the truncation issue; no unrelated modifications to other functionality are present.

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✨ Finishing touches

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coderabbitai

Actionable comments posted: 1

server/api/registry/readme/[...pkg].get.ts

codecov · 2026-02-13T08:20:59Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

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coderabbitai

Actionable comments posted: 1

🧹 Nitpick comments (1)

test/unit/server/utils/readme-loaders.spec.ts (1)
186-207: Consider adding a test for when packageData.versions is undefined.

All current tests provide versions: {} or with specific entries. Adding a test where versions is omitted entirely would help catch potential TypeError regressions when falling back to packument readme for a specific version.
🧪 Suggested test case
it('handles undefined versions gracefully when falling back', async () => {
  fetchNpmPackageMock.mockResolvedValue({
    'readme': '# Top-level readme',
    'repository': undefined,
    // versions intentionally omitted
    'dist-tags': { latest: '1.0.0' },
  })
  parseRepositoryInfoMock.mockReturnValue(undefined)
  const fetchMock = vi.fn().mockResolvedValue({ ok: false })
  vi.stubGlobal('fetch', fetchMock)

  const result = await resolvePackageReadmeSource('pkg/v/1.0.0')

  expect(result).toMatchObject({
    packageName: 'pkg',
    version: '1.0.0',
    markdown: undefined, // falls through since versions?.['1.0.0'] is undefined
  })
})

server/utils/readme-loaders.ts

danielroe

👌

The npm registry truncates the packument readme field at exactly 65,536 characters, causing large READMEs to render incomplete. Fetch the actual README file from jsDelivr CDN (npm tarball) as the primary source, falling back to the packument field when jsDelivr doesn't have it. Closes npmx-dev#1458

…cated The npm registry truncates the packument readme field at 65,536 characters. When the readme length exceeds 64,000 characters, fetch the full file from jsDelivr CDN instead. Closes npmx-dev#1458

server/utils/readme-loaders.ts

Move the length comparison into the if condition so JS short-circuits past it when the earlier checks already trigger the jsDelivr fetch.

github-actions · 2026-02-13T09:49:28Z

Thanks for your first contribution, @lukeocodes! ⭐

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vercel bot deployed to Preview – npmx.dev February 13, 2026 08:11 View deployment

lukeocodes changed the title ~~fix(readme): avoid npm registry 64K truncation by preferring jsDelivr~~ fix(ui): avoid npm registry 64K truncation by preferring jsDelivr Feb 13, 2026

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danielroe changed the title ~~fix(ui): avoid npm registry 64K truncation by preferring jsDelivr~~ fix: use jsdelivr when npm has a truncated readme Feb 13, 2026

danielroe enabled auto-merge February 13, 2026 09:27

lukeocodes added 2 commits February 13, 2026 09:27

fix(readme): fetch from jsDelivr when packument readme is likely trun…

cbba528

…cated The npm registry truncates the packument readme field at 65,536 characters. When the readme length exceeds 64,000 characters, fetch the full file from jsDelivr CDN instead. Closes npmx-dev#1458

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lukeocodes force-pushed the fix/readme-truncation branch from 8b8f782 to cbba528 Compare February 13, 2026 09:27

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server/utils/readme-loaders.ts Outdated Show resolved Hide resolved

refactor(readme): avoid computing truncation check unnecessarily

0c2ac8a

Move the length comparison into the if condition so JS short-circuits past it when the earlier checks already trigger the jsDelivr fetch.

lukeocodes requested a review from danielroe February 13, 2026 09:42

danielroe approved these changes Feb 13, 2026

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danielroe enabled auto-merge February 13, 2026 09:43

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danielroe added this pull request to the merge queue Feb 13, 2026

Merged via the queue into npmx-dev:main with commit 6a4aa00 Feb 13, 2026
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fix: use jsdelivr when npm has a truncated readme#1459

fix: use jsdelivr when npm has a truncated readme#1459
danielroe merged 3 commits intonpmx-dev:mainfrom
lukeocodes:fix/readme-truncation

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