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fix: improve no-cors request block error #21902

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Merged
sapphi-red merged 1 commit into from
Mar 19, 2026
Merged

fix: improve no-cors request block error #21902

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10 changes: 8 additions & 2 deletions packages/vite/src/node/server/middlewares/rejectNoCorsRequest.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -25,9 +25,15 @@ export function rejectNoCorsRequestMiddleware(): Connect.NextHandleFunction {
// we only need to block classic script requests
req.headers['sec-fetch-dest'] === 'script'
) {
res.statusCode = 403
// Send a JavaScript code instead of 403 so that the error is shown in the devtools
// If we send 403, the browser will avoid loading the body of the response
// and just show "Failed to load" error without the detailed message.
res.setHeader('Content-Type', 'text/javascript')
res.end(
'Cross-origin requests for classic scripts must be made with CORS mode enabled. Make sure to set the "crossorigin" attribute on your <script> tag.',
`throw new Error(${JSON.stringify(
'[Vite] Cross-origin requests for classic scripts must be made with CORS mode enabled.' +
' Make sure to set the "crossorigin" attribute on your <script> tag.',
)});`,
)
return
}
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6 changes: 5 additions & 1 deletion playground/fs-serve/__tests__/commonTests.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -495,7 +495,7 @@ test.runIf(isServe)(
reject(e)
})
})
expect(res.statusCode).toBe(403)
expect(res.statusCode).toBe(200)
const body = Buffer.concat(await ArrayFromAsync(res)).toString()
expect(body).toContain(
'Cross-origin requests for classic scripts must be made with CORS mode enabled.',
Expand Down Expand Up @@ -531,6 +531,10 @@ test.runIf(isServe)(
})
})
expect(res.statusCode).not.toBe(403)
const body = Buffer.concat(await ArrayFromAsync(res)).toString()
expect(body).not.toContain(
'Cross-origin requests for classic scripts must be made with CORS mode enabled.',
)
},
)

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