Coverage in library `unit-test` includes dependent library files and does not reduce runtime when using coverage.include

まず、依存関係のある2つの Angular workspace ライブラリと @angular/build:unit-test builder を使用して、ng test lib-a --coverage で問題を再現します。coverage.include を指定した場合と指定しない場合の coverage 出力と実行時間を比較します。依存ライブラリのファイルが除外され、coverage を制限することで実行時間も短縮されれば完了です。

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 unit tests for a library with @angular/build:unit-test, the coverage report includes files from other workspace libraries that the tested library depends on, which is unexpected.

Although this can be restricted with coverage.include, coverage execution time remains unchanged.

Minimal Reproduction

1. Create two Angular libraries in the workspace (e.g. lib-a and lib-b)
2. Make lib-a depend on lib-b
3. Add a unit test in lib-a
4. Run tests with coverage enabled:

ng test lib-a --coverage

Observed behavior

• The coverage report contains files from lib-b, even though only lib-a is being tested.
• Restricting coverage.include changes the generated report but does not noticeably reduce execution time.

Performance

Times below are for a single library test run inside a larger Angular monorepo where the tested library depends on ~7 other libraries from the same workspace.
Execution times vary depending on configuration (development vs production) used to build each of the libraries.

Without coverage:

Duration 24.94s
(transform 62.28s, setup 6.91s, import 98.85s, tests 982ms, environment 13.89s)

With coverage (production build):

Duration 154.60s
(transform 78.24s, setup 13.24s, import 135.76s, tests 1.58s, environment 19.90s)

With coverage (development build)

Duration 201.20s
(transform 57.83s, setup 10.09s, import 99.85s, tests 1.25s, environment 15.00s)

Your Environment

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

Angular CLI       : 22.0.4
Angular           : 22.0.4
Node.js           : 24.16.0
Package Manager   : npm 11.13.0
Operating System  : linux x64

┌───────────────────────────────────┬───────────────────┬───────────────────┐
│ Package                           │ Installed Version │ Requested Version │
├───────────────────────────────────┼───────────────────┼───────────────────┤
│ @angular/animations               │ 22.0.4            │ ^22.0.4           │
│ @angular/build                    │ 22.0.4            │ ^22.0.4           │
│ @angular/cli                      │ 22.0.4            │ ^22.0.4           │
│ @angular/common                   │ 22.0.4            │ ^22.0.4           │
│ @angular/compiler                 │ 22.0.4            │ ^22.0.4           │
│ @angular/compiler-cli             │ 22.0.4            │ ^22.0.4           │
│ @angular/core                     │ 22.0.4            │ ^22.0.4           │
│ @angular/forms                    │ 22.0.4            │ ^22.0.4           │
│ @angular/localize                 │ 22.0.4            │ ^22.0.4           │
│ @angular/platform-browser         │ 22.0.4            │ ^22.0.4           │
│ @angular/platform-browser-dynamic │ 22.0.4            │ ^22.0.4           │
│ @angular/router                   │ 22.0.4            │ ^22.0.4           │
│ @angular/service-worker           │ 22.0.4            │ ^22.0.4           │
│ ng-packagr                        │ 22.0.0            │ ^22.0.0           │
│ rxjs                              │ 7.8.2             │ ~7.8.2            │
│ typescript                        │ 6.0.3             │ ^6.0.3            │
│ vitest                            │ 4.1.9             │ ^4.1.9            │
│ zone.js                           │ 0.16.2            │ ~0.16.2           │
└───────────────────────────────────┴───────────────────┴───────────────────┘

Anything else relevant?

No response