ng generate web-worker adds webWorkerTsConfig to the @angular/build:unit-test target, breaking ng test #34385

Command

generate

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

Running ng generate web-worker in a newly created application breaks ng test.

The web-worker schematic adds webWorkerTsConfig to the options of the project's test target, regardless of
which builder that target uses. New applications use the @angular/build:unit-test builder, whose schema does not
have a webWorkerTsConfig option, so ng test fails schema validation afterwards.

The option is still needed on the build target (where the schematic also adds it). Removing it from the test
target makes ng test pass again, including with the worker in place.

Relevant code: packages/schematics/angular/web-worker/index.ts

if (testTarget) {
  (testTarget.options ??= {}).webWorkerTsConfig ??= workerConfigPath;
}

Minimal Reproduction

1. ng new ww-repro --defaults
2. cd ww-repro
3. ng test --watch=false → passes
4. ng generate web-worker app
5. ng test --watch=false → fails with the error below

After step 4, the test target in angular.json is:

"test": {
  "builder": "@angular/build:unit-test",
  "options": {
    "webWorkerTsConfig": "tsconfig.worker.json"
  }
}

Deleting webWorkerTsConfig from the test target options makes ng test pass again.

Exception or Error

Error: Schema validation failed with the following errors:
  Unknown option "webWorkerTsConfig". Valid options are: buildTarget, tsConfig, runner, runnerConfig, browsers, browserViewport, include, exclude, filter, watch, headless, debug, ui, isolate, splitting, quiet, coverage, coverageInclude, coverageExclude, coverageReporters, coverageThresholds, coverageWatermarks, reporters, outputFile, providersFile, setupFiles, progress, listTests, dumpVirtualFiles.

Your Environment

Angular CLI       : 22.2.3
Node.js           : 24.15.0
Package Manager   : npm 11.12.1
OS                : darwin arm64
@angular/build    : 22.2.3
vitest            : 5.0.5

Anything else relevant?

Suggested fix: only add webWorkerTsConfig to the test target when it uses a Karma builder
(@angular-devkit/build-angular:karma / @angular/build:karma). The unit-test builder gets build options from
its buildTarget. Happy to send a PR with a spec.