Built .d.ts files contain js code

[mrginglymus]

Describe the bug

Found in dist/browser.d.ts, but may be present elsewhere, something is putting executable code in the declaration files.

Reproduction

https://www.npmjs.com/package/vitest?activeTab=code

1. import vitest/browser
2. Run tsc with skipLibCheck: false
3. Observe TS1183 and TS1039 errors

System Info

-

Used Package Manager

npm

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
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• The provided reproduction is a minimal reproducible example of the bug.

[hi-ogawa]

This looks like a bug of rollup-plugin-dts. Here is a repro https://stackblitz.com/edit/stackblitz-starters-4kre7v8f?file=dist%2Fentry.d.ts It's not likely we get a fix or find a fix since rollup-plugin-dts is in maintenance mode, so probably we should workaround on our side.

[mrginglymus]

@hi-ogawa looks like a fix might be in the works:

• Re-exporting types from another package are not properly marked as type-only export in declaration file. unjs/unbuild#422
• type only exports of classes are not respected Swatinem/rollup-plugin-dts#311
• fix: imports and exports follows type-only Swatinem/rollup-plugin-dts#333

[mrginglymus]

I tried building vitest using latest master of rollup-plugin-dts:

[!] (plugin dts) TypeError: Cannot read properties of undefined (reading 'forEach')
    at file:///C:/.../rollup-plugin-dts/dist/rollup-plugin-dts.mjs:616:61

:(

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tried putting a ? in to get through that error - it completes succesfully but the mergeNamespaces is still there.