fix(module-runner): handle non-ascii characters in base64 sourcemaps by WhiteKiwi · Pull Request #21985 · vitejs/vite

WhiteKiwi · 2026-03-23T00:47:40Z

Fix UTF-8 decoding issue caused by using atob for base64 decoding.
Use Buffer.from(..., 'base64').toString('utf-8') when available to ensure correct decoding.

Closes #21984

hi-ogawa · 2026-03-23T01:30:19Z

Is this somehow related to this? vitest-dev/vitest#9640

WhiteKiwi · 2026-03-23T03:02:27Z

Is this somehow related to this? vitest-dev/vitest#9640

Yes, this seems to be the same issue.

WhiteKiwi · 2026-03-23T03:03:57Z

I encountered this when updating snapshots after running tests. It seems to be the same issue.

WhiteKiwi · 2026-03-23T07:37:01Z

Added browser support for base64 UTF-8 decoding

WhiteKiwi · 2026-03-23T07:44:56Z

The bundle size limit was exceeded, so it was increased from 54 kB to 55 kB (53.87 kB → 54.10 kB).

belgattitude · 2026-03-23T10:24:57Z

packages/vite/src/module-runner/utils.ts

+    return new TextDecoder().decode(bytes)
+  }
+
+  return decodeURIComponent(escape(binary))


Isn’t escape deprecated ?

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/escape

Yes, it’s deprecated. I used TextDecoder for modern environments, and escape as a fallback for older ones.

It will be a bit slower in my experience. I think there’s more possible here.

Saw your change. Would hoist the textdecoder outside of the function to not reinstantiate all the time.

don’t know if this this function is used a lot in vite. If it’s the case I would probably try to optimize via conditional exports for each runtimes

I've applied the feedback here
9e7202b

afurm · 2026-03-23T15:48:08Z

Good iterative approach. On the escape/decodeURIComponent fallback: Vite's minimum supported Node version is 18, and TextDecoder has been available in Node since v11 (global since v16) and in all modern browsers for years. The fallback to the deprecated escape is effectively dead code for any environment Vite realistically runs in.

Removing it entirely would simplify the function and avoid shipping a deprecated API call. If there's a specific runtime that matters where TextDecoder is absent, it's worth calling that out explicitly in a comment rather than silently falling back to escape.

WhiteKiwi · 2026-03-24T00:26:27Z

Good iterative approach. On the escape/decodeURIComponent fallback: Vite's minimum supported Node version is 18, and TextDecoder has been available in Node since v11 (global since v16) and in all modern browsers for years. The fallback to the deprecated escape is effectively dead code for any environment Vite realistically runs in.

Removing it entirely would simplify the function and avoid shipping a deprecated API call. If there's a specific runtime that matters where TextDecoder is absent, it's worth calling that out explicitly in a comment rather than silently falling back to escape.

I've applied the feedback here
c35679d

packages/vite/src/module-runner/utils.ts

bluwy

Makes sense to me

hi-ogawa · 2026-03-27T03:48:15Z

Vitest CI got ReferenceError: TextDecoder is not defined https://github.com/vitest-dev/vitest/actions/runs/23629687860/job/68826224687?pr=9986#step:8:1908 Probably due to this change and Vitest side needs to do something.

sapphi-red · 2026-03-27T04:00:37Z

Hmm, I've checked that TextDecoder is available in Node 11+ so I thought it won't cause problems.

hi-ogawa · 2026-03-27T04:36:38Z

I think this is some node vm or vitest vm quirks. I couldn't reproduce with simple test case, so it's possible that Vitest CI quirk.

| datasource | package | from | to | | ---------- | ------- | ----- | ----- | | npm | vite | 7.3.1 | 8.0.3 | ## [v8.0.3](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#small-803-2026-03-26-small) ##### Features - update rolldown to 1.0.0-rc.12 ([#22024](vitejs/vite#22024)) ([84164ef](vitejs/vite@84164ef)) ##### Bug Fixes - **html:** cache unfiltered CSS list to prevent missing styles across entries ([#22017](vitejs/vite#22017)) ([5464190](vitejs/vite@5464190)) - **module-runner:** handle non-ascii characters in base64 sourcemaps ([#21985](vitejs/vite#21985)) ([77c95bf](vitejs/vite@77c95bf)) - **module-runner:** skip re-import if the runner is closed ([#22020](vitejs/vite#22020)) ([ee2c2cd](vitejs/vite@ee2c2cd)) - **optimizer:** scan is not resolving sub path import if used in a glob import ([#22018](vitejs/vite#22018)) ([ddfe20d](vitejs/vite@ddfe20d)) - **ssr:** ssrTransform incorrectly rewrites `meta` identifier inside `import.meta` when a binding named `meta` exists ([#22019](vitejs/vite#22019)) ([cff5f0c](vitejs/vite@cff5f0c)) ##### Miscellaneous Chores - **deps:** bump picomatch from 4.0.3 to 4.0.4 ([#22027](vitejs/vite#22027)) ([7e56003](vitejs/vite@7e56003)) ##### Tests - **html:** add tests for `getCssFilesForChunk` ([#22016](vitejs/vite#22016)) ([43fbbf9](vitejs/vite@43fbbf9)) ## [v8.0.2](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#small-802-2026-03-23-small) ##### Features - update rolldown to 1.0.0-rc.11 ([#21998](vitejs/vite#21998)) ([ff91c31](vitejs/vite@ff91c31)) ##### Bug Fixes - **deps:** update all non-major dependencies ([#21988](vitejs/vite#21988)) ([9b7d150](vitejs/vite@9b7d150)) ##### Miscellaneous Chores - **deps:** update dependency [@vitejs/devtools](https://github.com/vitejs/devtools) to ^0.1.5 ([#21992](vitejs/vite#21992)) ([b2dd65b](vitejs/vite@b2dd65b)) ## [v8.0.1](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#small-801-2026-03-19-small) ##### Features - update rolldown to 1.0.0-rc.10 ([#21932](vitejs/vite#21932)) ([b3c067d](vitejs/vite@b3c067d)) ##### Bug Fixes - **bundled-dev:** properly disable `inlineConst` optimization ([#21865](vitejs/vite#21865)) ([6d97142](vitejs/vite@6d97142)) - **css:** lightningcss minify failed when `build.target: 'es6'` ([#21933](vitejs/vite#21933)) ([5fcce46](vitejs/vite@5fcce46)) - **deps:** update all non-major dependencies ([#21878](vitejs/vite#21878)) ([6dbbd7f](vitejs/vite@6dbbd7f)) - **dev:** always use ESM Oxc runtime ([#21829](vitejs/vite#21829)) ([d323ed7](vitejs/vite@d323ed7)) - **dev:** handle concurrent restarts in `_createServer` ([#21810](vitejs/vite#21810)) ([40bc729](vitejs/vite@40bc729)) - handle `+` symbol in package subpath exports during dep optimization ([#21886](vitejs/vite#21886)) ([86db93d](vitejs/vite@86db93d)) - improve `no-cors` request block error ([#21902](vitejs/vite#21902)) ([5ba688b](vitejs/vite@5ba688b)) - use precise regexes for transform filter to avoid backtracking ([#21800](vitejs/vite#21800)) ([dbe41bd](vitejs/vite@dbe41bd)) - **worker:** `require(json)` result should not be wrapped ([#21847](vitejs/vite#21847)) ([0672fd2](vitejs/vite@0672fd2)) - **worker:** make worker output consistent with client and SSR ([#21871](vitejs/vite#21871)) ([69454d7](vitejs/vite@69454d7)) ##### Miscellaneous Chores - add changelog rearrange script ([#21835](vitejs/vite#21835)) ([efef073](vitejs/vite@efef073)) - **deps:** bump required `@vitejs/devtools` version to 0.1+ ([#21925](vitejs/vite#21925)) ([12932f5](vitejs/vite@12932f5)) - **deps:** update rolldown-related dependencies ([#21787](vitejs/vite#21787)) ([1af1d3a](vitejs/vite@1af1d3a)) - rearrange 8.0 changelog ([8e05b61](vitejs/vite@8e05b61)) - rearrange 8.0 changelog ([#21834](vitejs/vite#21834)) ([86edeee](vitejs/vite@86edeee)) ## [v8.0.0](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#800-2026-03-12) ##### Features - update rolldown to 1.0.0-rc.9 ([#21813](vitejs/vite#21813)) ([f05be0e](vitejs/vite@f05be0e)) - warn when `vite-tsconfig-paths` plugin is detected ([#21781](vitejs/vite#21781)) ([ada493e](vitejs/vite@ada493e)) ##### Bug Fixes - **deps:** update all non-major dependencies ([#21786](vitejs/vite#21786)) ([eaa4352](vitejs/vite@eaa4352))

fix: Fix utf8 decoding issue

f29c704

WhiteKiwi changed the title ~~fix: Fix utf8 decoding issue~~ fix: fix utf8 decoding issue Mar 23, 2026

Merge branch 'main' into fix/utf8-decoding-issue

e5cc647

fix: support UTF-8 decoding for base64 in browser

a7c5ac7

WhiteKiwi and others added 2 commits March 23, 2026 16:37

Merge branch 'main' into fix/utf8-decoding-issue

00d5db8

fix: Increase bundle size limit

1752909

WhiteKiwi requested a review from themavik March 23, 2026 07:50

belgattitude reviewed Mar 23, 2026

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Merge branch 'main' into fix/utf8-decoding-issue

59a7b8b

WhiteKiwi requested a review from belgattitude March 23, 2026 10:37

WhiteKiwi and others added 2 commits March 23, 2026 20:09

Merge branch 'main' into fix/utf8-decoding-issue

699327e

perf: reuse TextDecoder and optimize per runtime

9e7202b

WhiteKiwi and others added 2 commits March 24, 2026 09:25

fix: use TextDecoder only in decodeBase64

c35679d

Merge branch 'main' into fix/utf8-decoding-issue

5cb6663

graphite-app bot reviewed Mar 24, 2026

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packages/vite/src/module-runner/utils.ts Show resolved Hide resolved

bluwy approved these changes Mar 25, 2026

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sapphi-red removed request for belgattitude and themavik March 25, 2026 04:18

sapphi-red added feat: ssr p2-edge-case Bug, but has workaround or limited in scope (priority) labels Mar 25, 2026

sapphi-red changed the title ~~fix: fix utf8 decoding issue~~ fix(module-runner): handle non-ascii characters in base64 sourcemaps Mar 25, 2026

sapphi-red approved these changes Mar 25, 2026

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sapphi-red merged commit 77c95bf into vitejs:main Mar 25, 2026
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hi-ogawa mentioned this pull request Mar 27, 2026

Vite 8 CI fails with ReferenceError: TextDecoder is not defined vitest-dev/vitest#9987

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Copilot AI mentioned this pull request Mar 27, 2026

[WIP] Investigate Vite 8 CI failure with TextDecoder reference error vitest-dev/vitest#9988

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hi-ogawa mentioned this pull request Mar 27, 2026

test: add TextDecoder/TextEncoder to custom environment example to fix Vite 8 vitest-dev/vitest#9989

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