`angular.json` overrides `watch` and `coverage` options from `vitest.config.ts`

[ArturMroz]

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 response

Description

When running tests through the Angular CLI with Vitest, watch and coverage options defined in vitest.config.ts are silently overridden by default settings from angular.json.

angular.json:

"test": {
  "builder": "@angular/build:unit-test",
  "options": {
    "runner": "vitest",
    "runnerConfig": "vitest.config.ts"
  }
}

vitest.config.ts:

export default defineConfig({
  test: {
    watch: false,
    reporters: [
      'default',
      ['junit', { outputFile: "tmp/test-results/junit.xml" }]
    ],
    coverage: {
      enabled: true,
      reportsDirectory: "tmp/coverage",
      reporter: ['cobertura', 'lcov'],
    }
  }
});

---

Expected behaviour

Either:

1. The CLI should respect the values defined in vitest.config.ts for options such as watch and coverage, or

2. The documentation should clearly list all options that Angular CLI overrides (atm it only states that 'The CLI will also override certain properties (test.projects, test.include) to ensure proper operation.').

It is difficult to reason about which configuration source has precedence. Especially when coverage and watch flags aren't even configured in angular.json and their default values are used.

Minimal Reproduction

Repro repo: https://github.com/ArturMroz/vitest-flags-repro

1. Create and configure vitest.config.ts and angular.json (already done in the repo)
2. Run ng test
3. Observe: watch mode is enabled and no coverage is created

Exception or Error

Your Environment

Angular CLI       : 21.2.2
Angular           : 21.2.4
Node.js           : 22.18.0
Package Manager   : npm 10.9.3
Operating System  : win32 x64

┌───────────────────────────┬───────────────────┬───────────────────┐
│ Package                   │ Installed Version │ Requested Version │
├───────────────────────────┼───────────────────┼───────────────────┤
│ @angular/build            │ 21.2.2            │ ^21.2.2           │
│ @angular/cli              │ 21.2.2            │ ^21.2.2           │
│ @angular/common           │ 21.2.4            │ ^21.2.0           │
│ @angular/compiler         │ 21.2.4            │ ^21.2.0           │
│ @angular/compiler-cli     │ 21.2.4            │ ^21.2.0           │
│ @angular/core             │ 21.2.4            │ ^21.2.0           │
│ @angular/forms            │ 21.2.4            │ ^21.2.0           │
│ @angular/platform-browser │ 21.2.4            │ ^21.2.0           │
│ @angular/router           │ 21.2.4            │ ^21.2.0           │
│ rxjs                      │ 7.8.2             │ ~7.8.0            │
│ typescript                │ 5.9.3             │ ~5.9.2            │
│ vitest                    │ 4.1.0             │ ^4.0.8            │
└───────────────────────────┴───────────────────┴───────────────────┘

Anything else relevant?

No response