@angular/build: ng test fails on Windows — setupFiles path not normalized to POSIX, breaks import resolution

[aquesada-planhub]

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

No — unit-test/Vitest builder is new; broken on Windows since it shipped

Description

Windows-only Failed to resolve import in vite:import-analysis; root-cause table (spec keys POSIX via toPosixPath vs setup-file key backslashes via path.join) → map miss → raw-source cascade; the one-line toPosixPath fix diff; note on why resolve.alias isn't a valid workaround

Minimal Reproduction

1. ng new repro --defaults --style=css --routing=false
2. cd repro

Then:

• tsconfig alias — add "paths": { "@lib/*": ["src/lib/*"] } and "baseURL" to tsconfig.json
• aliased module — src/lib/greeting.ts → export const greeting = 'hello';
• setup file — src/test-setup.ts → import { greeting } from '@lib/greeting';
• wire the builder in angular.json under the project's test target:

"test": {
  "builder": "@angular/build:unit-test",
  "options": {
    "buildTarget": "repro:build:development",
    "tsConfig": "tsconfig.spec.json",
    "runner": "vitest",
    "setupFiles": ["src/test-setup.ts"]
  }
}

• run: ng test

Expected: alias resolves (as it does at build time), tests run.

Actual (Windows): Failed to resolve import "@lib/greeting" from "src/test-setup.ts" — Plugin: vite:import-analysis, 0 tests. Same repo passes on macOS/Linux.

Exception or Error

Error: Failed to resolve import "@lib/greeting" from "src/test-setup.ts". Does the file exist?
Plugin: vite:import-analysis

Your Environment

_                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/
    

Angular CLI       : 22.0.3
Angular           : 22.0.2
Node.js           : 22.22.3
Package Manager   : npm 12.0.2
Operating System  : win32 x64

┌───────────────────────────────────┬───────────────────┬───────────────────┐
│ Package                           │ Installed Version │ Requested Version │
├───────────────────────────────────┼───────────────────┼───────────────────┤
│ @angular-devkit/architect         │ 0.2200.3          │ 0.2200.3          │
│ @angular-devkit/build-angular     │ 22.0.3            │ ^22.0.3           │
│ @angular-devkit/core              │ 22.0.3            │ ^22.0.3           │
│ @angular/animations               │ 22.0.2            │ ^22.0.2           │
│ @angular/build                    │ 22.0.6            │ ^22.0.6           │
│ @angular/cdk                      │ 22.0.2            │ ^22.0.2           │
│ @angular/cli                      │ 22.0.3            │ ^22.0.3           │
│ @angular/common                   │ 22.0.2            │ ^22.0.2           │
│ @angular/compiler                 │ 22.0.2            │ ^22.0.2           │
│ @angular/compiler-cli             │ 22.0.2            │ ^22.0.2           │
│ @angular/core                     │ 22.0.2            │ ^22.0.2           │
│ @angular/elements                 │ 22.0.2            │ ^22.0.2           │
│ @angular/forms                    │ 22.0.2            │ ^22.0.2           │
│ @angular/google-maps              │ 22.0.2            │ ^22.0.2           │
│ @angular/localize                 │ 22.0.2            │ ^22.0.2           │
│ @angular/material                 │ 22.0.2            │ ^22.0.2           │
│ @angular/platform-browser         │ 22.0.2            │ ^22.0.2           │
│ @angular/platform-browser-dynamic │ 22.0.2            │ ^22.0.2           │
│ @angular/router                   │ 22.0.2            │ ^22.0.2           │
│ ng-packagr                        │ 22.0.0            │ ^22.0.0           │
│ rxjs                              │ 7.8.2             │ ~7.8.0            │
│ typescript                        │ 6.0.3             │ ~6.0.0            │
│ vitest                            │ 4.1.10            │ ^4.1.10           │
│ zone.js                           │ 0.16.2            │ ~0.16.0           │
└───────────────────────────────────┴───────────────────┴───────────────────┘

Anything else relevant?

Windows-only, only setup files importing first-party modules, patch-package verification numbers