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fix(ssr): class property keys hoisting matching imports#22199

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sapphi-red merged 1 commit intovitejs:mainfrom
SunsetFi:class-properties-name-collision-hoisting
Apr 9, 2026
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fix(ssr): class property keys hoisting matching imports#22199
sapphi-red merged 1 commit intovitejs:mainfrom
SunsetFi:class-properties-name-collision-hoisting

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@SunsetFi SunsetFi commented Apr 8, 2026 •
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In an SSR environment, vite will incorrectly hoist imports whose names match class property keys.

This was first identified in vitest:
Reproduction: https://github.com/SunsetFi/vitest-class-method-name-collision/tree/main
Issue: vitest-dev/vitest#10093
PR: vitest-dev/vitest#10094

This PR was made on the request of @sheremet-va, over in the vitest PR for this issue.

I do not have a reproduction at hand, but the class props test in ssrTransform.spec.ts demonstrate the bug occurring:

    const __vite_ssr_import_0__ = await __vite_ssr_import__("vue", {"importedNames":["remove","add"]});


    // Incorrect: Should not be hoisted, as the class identifiers are keys, not references
    const add = __vite_ssr_import_0__.add;
    const remove = __vite_ssr_import_0__.remove;
    class A {
      remove = 1
      add = null
    }

This PR provides 2 code changes, both related:

Based on our research, the initial reason for the identifier references getting hoisted was introduced due to #2221. In order to reference a variable in the 'extends' directive of a class, the variable must not be a property path:

// Wrong
class MyClass extends __vite_ssr_import_0__.MySuper {}

The fix in #2221 was to extract it to its own variable:

// The intent behind the fix
const MySuper = __vite_ssr_import_0__.MySuper;
class MyClass extends MySuper {}

However, at some point, it was noted that vitest was mangling class property keys as if they were imports: vitest-dev/vitest#303.

The fix for this was implemented in #6261. However, the fix itself seems to function only indirectly, and it introduced the bug seen in vitest-dev/vitest#10093. The effect of this fix was to treat all class property key identifiers as if they were super references in class declarations. This consequently triggers the variable hoisting behavior on all matches. The root cause, that class property keys were treated as references to identifiers, was never resolved, and still surfaces through the hoisting mechanism kicking in when it sees an import that coincidentally matches the name of a class property key.

The appropriate fix for vitest-dev/vitest#303 seems to be instead changing isRefIdentifier to correctly specify that non-computed class property key identifiers are not references.

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SunsetFi commented Apr 8, 2026

Unfortunately, I am totally unable to put together a reproduction to this. I am not too familiar with SSR in vite, and try as I might, I cannot get ssrTransform to be invoked, either by build or by dev mode.

If anyone knows the conditions that this function runs, I can put together a reproduction.

@sapphi-red sapphi-red added p3-minor-bug An edge case that only affects very specific usage (priority) feat: ssr labels Apr 9, 2026
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sapphi-red approved these changes Apr 9, 2026
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The change makes sense to me. I think we don't need a reproduction for this 👍

@sapphi-red sapphi-red merged commit e137601 into vitejs:main Apr 9, 2026
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@diegohaz diegohaz mentioned this pull request Apr 13, 2026
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renovate bot added a commit to andrei-picus-tink/auto-renovate that referenced this pull request Apr 15, 2026
@renovate
Update dependency vite to v8
07334ca 
| datasource | package | from  | to    |
| ---------- | ------- | ----- | ----- |
| npm        | vite    | 7.3.1 | 8.0.8 |


## [v8.0.8](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#small-808-2026-04-09-small)

##### Features

- update rolldown to 1.0.0-rc.15 ([#22201](vitejs/vite#22201)) ([6baf587](vitejs/vite@6baf587))

##### Bug Fixes

- avoid `dns.getDefaultResultOrder` temporary ([#22202](vitejs/vite#22202)) ([15f1c15](vitejs/vite@15f1c15))
- **ssr:** class property keys hoisting matching imports ([#22199](vitejs/vite#22199)) ([e137601](vitejs/vite@e137601))


## [v8.0.7](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#small-807-2026-04-07-small)

##### Bug Fixes

- use sync dns.getDefaultResultOrder instead of dns.promises ([#22185](vitejs/vite#22185)) ([5c05b04](vitejs/vite@5c05b04))


## [v8.0.6](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#small-806-2026-04-07-small)

##### Features

- update rolldown to 1.0.0-rc.13 ([#22097](vitejs/vite#22097)) ([51d3e48](vitejs/vite@51d3e48))

##### Bug Fixes

- **css:** avoid mutating sass error multiple times ([#22115](vitejs/vite#22115)) ([d5081c2](vitejs/vite@d5081c2))
- **optimize-deps:** hoist CJS interop assignment ([#22156](vitejs/vite#22156)) ([17a8f9e](vitejs/vite@17a8f9e))

##### Performance Improvements

- early return in `getLocalhostAddressIfDiffersFromDNS` when DNS order is `verbatim` ([#22151](vitejs/vite#22151)) ([56ec256](vitejs/vite@56ec256))

##### Miscellaneous Chores

- **create-vite:** remove unnecessary DOM.Iterable ([#22168](vitejs/vite#22168)) ([bdc53ab](vitejs/vite@bdc53ab))
- replace remaining prettier script ([#22179](vitejs/vite#22179)) ([af71fb2](vitejs/vite@af71fb2))


## [v8.0.5](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#small-805-2026-04-06-small)

##### Bug Fixes

- apply server.fs check to env transport ([#22159](vitejs/vite#22159)) ([f02d9fd](vitejs/vite@f02d9fd))
- avoid path traversal with optimize deps sourcemap handler ([#22161](vitejs/vite#22161)) ([79f002f](vitejs/vite@79f002f))
- check `server.fs` after stripping query as well ([#22160](vitejs/vite#22160)) ([a9a3df2](vitejs/vite@a9a3df2))
- disallow referencing files outside the package from sourcemap ([#22158](vitejs/vite#22158)) ([f05f501](vitejs/vite@f05f501))


## [v8.0.4](https://github.com/vitejs/vite/blob/HEAD/packages/vite/CHANGELOG.md#small-804-2026-04-06-small)

##### Features

- allow esbuild 0.28 as peer deps ([#22155](vitejs/vite#22155)) ([b0da973](vitejs/vite@b0da973))
- **hmr:** truncate list of files on hmr update ([#21535](vitejs/vite#21535)) ([d00e806](vitejs/vite@d00e806))
- **optimizer:** log when dependency scanning or bundling takes over 1s ([#21797](vitejs/vite#21797)) ([f61a1ab](vitejs/vite@f61a1ab))

##### Bug Fixes

- `hasBothRollupOptionsAndRolldownOptions` should return `false` for proxy case ([#22043](vitejs/vite#22043)) ([99897d2](vitejs/vite@99897d2))
- add types for `vite/modulepreload-polyfill` ([#22126](vitejs/vite#22126)) ([17330d2](vitejs/vite@17330d2))
- **deps:** update all non-major dependencies ([#22073](vitejs/vite#22073)) ([6daa10f](vitejs/vite@6daa10f))
- **deps:** update all non-major dependencies ([#22143](vitejs/vite#22143)) ([22b0166](vitejs/vite@22b0166))
- **resolve:** resolve tsconfig paths starting with `#` ([#22038](vitejs/vite#22038)) ([3460fc5](vitejs/vite@3460fc5))
- **ssr:** use browser platform for webworker SSR builds (fix [#21969](vitejs/vite#21969)) ([#21963](vitejs/vite#21963)) ([364c227](vitejs/vite@364c227))

##### Documentation

- add `environment.fetchModule` documentation ([#22035](vitejs/vite#22035)) ([54229e7](vitejs/vite@54229e7))

##### Miscellaneous Chores

- **deps:** update rolldown-related dependencies ([#21989](vitejs/vite#21989)) ([0ded627](vitejs/vite@0ded627))

##### Code Refactoring

- upgrade to typescript 6 ([#22110](vitejs/vite#22110)) ([cc41398](vitejs/vite@cc41398))


## [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))


## [v7.3.2](https://github.com/vitejs/vite/releases/tag/v7.3.2)

Please refer to [CHANGELOG.md](https://github.com/vitejs/vite/blob/v7.3.2/packages/vite/CHANGELOG.md) for details.
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