Vitest coverage issue `vite:import-analysis` error `Pre-transform error: Failed to resolve import "#/util" from "src/app/app.ts". Does the file exist?`

Start by reproducing the failure with the listed Angular project, tsconfig.json path alias, src/app/app.ts import, and the ng test command, comparing Vitest 4.1.0 with 4.0.8. Trace coverage generation and source-map handling when the shared app chunk references the alias. Done means browser coverage completes without vite:import-analysis errors while the alias resolves.

Command

test

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

vitest@4.0.8

Description

I'm not sure if this issue is an issue with Vitest, or the Angular CLI integration with Vitest. I put the issue here, because I have no idea how to reproduce this issue without Angular at the moment.

The issue is that when using tsconfig.json property paths and running browser tests with coverage, these paths will not used when Vitest tries to read coverage from source maps. The requirement seems to be that a shared chunk exists (import './app' in the repro steps).

This results in errors during coverage generation, but tests do not crash. The errors come from Vite's dev server pre transforming original .ts files referenced in source-maps.

Requirements

• Using paths in tsconfig.json
• Angular CLI + eslint creates a shared chunk that has the paths in it's sourcemap
• Vitest with browsers + coverage + coverageInclude
• Vitest v4.1.0+

Minimal Reproduction

1. Init Angular project & install vitest coverage & browser packages

npx @angular/cli@21.1.5 new ng21.1.5 -s -t --style css --no-ssr --ai-config none
npm i -E -D vitest@4.1.0 @vitest/browser-playwright@4.1.0 @vitest/coverage-v8@4.1.0 playwright

2. Add src/app/util.ts file

export const greet = 'Hello';

3. Add a path alias to util file

{
  "compilerOptions": {
    "paths": {
      "#/util": ["./src/app/util.ts"]
    }
  }
}

4. Make App (app.ts) use value from util.ts

import { greet } from '#/util';
// ...
export class App {
  protected readonly title = signal(greet);
}

5. Add import to app.ts from app.config.ts

import './app';

6. Run tests with browser, coverage & coverage include

npx ng test --no-watch --browsers chromium --coverage --coverage-include src/app/**/*.ts

Exception or Error

There's logged errors for every file that uses the path alias, which in our project is most of them (e.g. `import { shared } from '#/core';`).


00:02:12 [vite] (client) Pre-transform error: Failed to resolve import "#/util" from "src/app/app.ts". Does the file exist?
  Plugin: vite:import-analysis
  File: C:/Users/foo/repro/src/app/app.ts:3:22
  11 |  import { Component, signal } from "@angular/core";
  12 |  import { RouterOutlet } from "@angular/router";
  13 |  import { greet } from "#/util";
     |                         ^
  14 |  export let App = class {
  15 |    title = signal(greet);

Your Environment

I've tried with `@angular/build` + `@angular/cli` at several versions, including `21.1.x` and `21.2.x`. Downgrading `vitest` to `4.0.8` fixes the issue, but `vitest@4.1.0` and `4.1.2` both failed.

----------------------------------------

Angular CLI       : 21.2.5
Angular           : 21.2.6
Node.js           : 25.8.2 (Unsupported)
Package Manager   : npm 11.11.1
Operating System  : win32 x64

┌───────────────────────────┬───────────────────┬───────────────────┐
│ Package                   │ Installed Version │ Requested Version │
├───────────────────────────┼───────────────────┼───────────────────┤
│ @angular/build            │ 21.2.5            │ ^21.1.5           │
│ @angular/cli              │ 21.2.5            │ ^21.1.5           │
│ @angular/common           │ 21.2.6            │ ^21.1.0           │
│ @angular/compiler         │ 21.2.6            │ ^21.1.0           │
│ @angular/compiler-cli     │ 21.2.6            │ ^21.1.0           │
│ @angular/core             │ 21.2.6            │ ^21.1.0           │
│ @angular/forms            │ 21.2.6            │ ^21.1.0           │
│ @angular/platform-browser │ 21.2.6            │ ^21.1.0           │
│ @angular/router           │ 21.2.6            │ ^21.1.0           │
│ rxjs                      │ 7.8.2             │ ~7.8.0            │
│ typescript                │ 5.9.3             │ ~5.9.2            │
│ vitest                    │ 4.1.0             │ 4.1.0             │
└───────────────────────────┴───────────────────┴───────────────────┘

Anything else relevant?

Does not seem to be OS specific. The issue is on GitHub Actions on Ubuntu, and locally on Windows.