TypeScript error when using Yarn PnP

[wojtekmaj]

Describe the bug

Error

The following error may appear while type checking, if using Yarn PnP:

yarn tsc             
.yarn/unplugged/vitest-virtual-635245b105/node_modules/vitest/dist/reporters-5f784f42.d.ts:15:25 - error TS2307: Cannot find module 'rollup' or its corresponding type declarations.

15 import * as rollup from 'rollup';
                           ~~~~~~~~

Found 1 error in .yarn/unplugged/vitest-virtual-635245b105/node_modules/vitest/dist/reporters-5f784f42.d.ts:15

Why this happens:

vitest imports rollup, while not declaring it as its dependency. This is illegal in Yarn PnP, and works "by miracle" in non-PnP setups.

Here's why.

Imagine vitest relies on [email protected] which in turn relies on bar. foo's maintainer finds a way to get rid of bar dependency without changing its public API. Releases this improvement as a non-breaking version, righfully so.

Now, if you relied on foo to provide vitest with bar, everything falls apart.

In fact, with Vite plans to replace rollup with rolldown the above is EXACTLY what might happen.

What we can do about it

Declare rollup as vitest's dependency.

Reproduction

n/a

System Info

System:
    OS: Windows 10 10.0.22621
    CPU: (8) x64 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
    Memory: 5.44 GB / 15.85 GB
  Binaries:
    Node: 20.9.0 - ~\AppData\Local\Temp\xfs-515b5efc\node.CMD
    Yarn: 4.0.0 - ~\AppData\Local\Temp\xfs-515b5efc\yarn.CMD
    npm: 10.1.0 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Chromium (118.0.2088.76)

Used Package Manager

yarn

Validations

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• 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.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[wojtekmaj]

Can confirm that adding:

packageExtensions:
  "vitest@*":
    dependencies:
      rollup: ^3.25.2

to .yarnrc.yml fixes the issue, which proves the suggested fix would have worked.

[sheremet-va]

Yeah, I wonder why it worked before. I noticed a rogue rollup import in types a few days ago - I wonder if it was added during the last update.

Vitest doesn't depend on rollup directly, Vite does, so I don't think we can specify it. However, this should change with #4368 when we upgrade to rollup 4 and have to use rollup/parseAst. I guess, we need to specify it as a peerDependency now, but I am afraid of type mismatches with Vite :(

[sheremet-va]

Can confirm, this is just what rollup bundles are because it's externalized when building Vitest: WorkspaceProject.prototype.getSourceMapModuleById returns (without an annotation) rollup.SourceMap. If vite decides to move away from rollup, this will be changed when Vitest is rebundled.

For now, we can just make the same interface manually and return it there, I guess.

[wojtekmaj]

I wonder if it was added during the last update.

0.33.0 didn't have it as far as I can see. 0.34.0 added the import in types-3c7dbfa5.d.ts.