Wrong Source Map for js files in SSR mode

[sheremet-va]

Describe the bug

When transforming JS files with server.transformRequest and enabled SSR flag, it returns invalid source map. sourceContent includes already processed import paths instead of the original ones.

To run code in reproduction:

node vite-repro.mjs

It was noticed in Vitest, because snapshots rely on source maps: vitest-dev/vitest#1376

Reproduction

https://stackblitz.com/edit/vitejs-vite-pacs84?file=vite-repro.mjs&view=editor

Used Package Manager

npm

Logs

No response

Validations

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• Read the Contributing Guidelines.
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• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/core instead.
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• The provided reproduction is a minimal reproducible example of the bug.

[sapphi-red]

It seems mappings field is correct (source-map-visualization). So to workaround just delete the incorrect sourcesContent field.

[sheremet-va]

Why does it return a content then 🤔 I see there is no sourcesContent field for typescript files, for example 🤔

Thank you for the workaround!

[sheremet-va]

I've managed to reproduce the error in Vitest with provided source map. I am not sure, where the error lies tho. Imagine, there are two files with the same content. One is js, the other is ts. When we try to access the same index, TS file returns correct one, but js returns incorrect one (one off). These indexes are coming from new Error().stack.

Reproduction:

https://stackblitz.com/edit/vitejs-vite-amcazy?file=tests%2Funit%2Futils%2Fdates.spec.ts,vite-repro.mjs,tests%2Funit%2Futils%2Fdates.spec.js

[sapphi-red]

source-map-visualization (ts)

I think 80 is correct instead of 81 here.

-const jsPosition = consumerJs.originalPositionFor({ line: 10, column: 81 });
-const tsPosition = consumerTs.originalPositionFor({ line: 8, column: 81 });
+const jsPosition = consumerJs.originalPositionFor({ line: 10, column: 80 });
+const tsPosition = consumerTs.originalPositionFor({ line: 8, column: 80 });

Why ts returns the same value with 80 and 81 is because it points the same segment.