The unit-test builder doesn't re-run test suites on changes to non-spec files

[brandonroberts]

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

Storybook has support for running component tests using Vitest. When trying to build a POC with the unit-test builder, I ran into two issues.

• Storybook can't transform the stories because the compiled code leads to file with just animport as its contents.
• Making changes to files that aren't in the include array doesn't trigger tests to be re-run.

I was able to work around the code import issue with a plugin that re-exports the chunks from compiled files
https://github.com/brandonroberts/angular-storybook-vitest/blob/main/vitest-storybook-base.config.ts#L16

Minimal Reproduction

https://github.com/brandonroberts/angular-storybook-vitest

1. Clone and install dependencies
2. Run npm run test-storybook
3. Note the tests pass
4. Make a change in one of the src/stories/*.stories.ts files
5. Note the build re-compiles but the tests aren't re-run.

The test-storybook target excludes the stories files because of the import issue so they are transpiled as-is.

https://github.com/brandonroberts/angular-storybook-vitest/blob/main/angular.json#L94

Exception or Error

No exception

Your Environment

Angular v21

Anything else relevant?

No response

[maruthang]

Hi, I'd like to work on this issue.

Root cause: In packages/angular/build/src/builders/unit-test/runners/vitest/executor.ts, the entryPointToTestFile map only contains .spec.ts files. When non-test files (services, components) change during watch mode, they're not in the map, and getModuleSpecifications() is never called for them — so no dependent tests are re-run.

Proposed fix: In the else branch (when a modified file isn't in the test map), call vitest.getModuleSpecifications() on the absolute output file path. Vitest's module graph correctly traverses backwards to find all dependent test specifications. This is consolidated into a single loop for clarity.

Submitting a PR now.