Bug: Upgraded to Angular 21 - Error: TestModule declaration has been passed into ng-mocks without Angular decorators

[Ryan-Cav]

Description of the bug

Upgraded to Angular 21 - Error: TestModule declaration has been passed into ng-mocks without Angular decorators

An example of the bug

Any and all MockProvider or MockProviders call results in the following error:

Error: TestModule declaration has been passed into ng-mocks without Angular decorators. Therefore, it cannot be properly handled. Highly likely, ng-mocks is imported in production code, or got a class without Angular decoration. Otherwise, please create an issue on github: https://github.com/help-me-mom/ng-mocks/issues/new?title=False%20positive%20ng-mocks%20not%20in%20JIT. Thank you in advance for support.
at error_missing_decorators (node_modules/ng-mocks/index.mjs:1:34634)
at node_modules/ng-mocks/index.mjs:1:35255
at core_reflect_module_resolve (node_modules/ng-mocks/index.mjs:1:35682)
at applyPlatformOverrideDef (node_modules/ng-mocks/index.mjs:1:123820)
at applyPlatformOverrides (node_modules/ng-mocks/index.mjs:1:124662)
at TestBedImpl.call (node_modules/ng-mocks/index.mjs:1:125950)
at TestBedImpl.configureTestingModule (node_modules/ng-mocks/index.mjs:1:108349)
at UserContext. (src/app/app.component.spec.ts:10:19)
at Generator.next ()
at asyncGeneratorStep (node_modules/@babel/runtime/helpers/esm/asyncToGenerator.js:3:1)

Tried multiple fresh npm installs, angular cache cleans, etc and cannot get around this without just moving off of ng-mocks yet it seems no one else has this issue...

Expected vs actual behavior

MockProvider calls work vs missing decorators error

[MaGnaL]

You're not the only one. I have the same problem. Updated to Angular 21 (within a Nx monorepo) and my karma test terminate with the same message, which is bad because almost all of my tests rely on ng-mocks.

Have you already tested whether this PR fixes the problem?
#12594

[MaGnaL]

I tried the code from the PR and it's not solving the problem for me.

[nawalesurekha2015-png]

I am also getting same issue in angular 21 updates. Any resolution for it? All tests are failing

Error: TestModule declaration has been passed into ng-mocks without Angular decorators. Therefore, it cannot be properly handled. Highly likely, ng-mocks is imported in production code, or got a class without Angular decoration. Otherwise, please create an issue on github: https://github.com/help-me-mom/ng-mocks/issues/new?title=False%20positive%20ng-mocks%20not%20in%20JIT. Thank you in advance for support.
at error_missing_decorators (http://localhost:9876/_karma_webpack_/vendor.js:658978:11)
at http://localhost:9876/_karma_webpack_/vendor.js:658985:27
at core_reflect_module_resolve (http://localhost:9876/_karma_webpack_/vendor.js:658998:5)
at applyPlatformOverrideDef (http://localhost:9876/_karma_webpack_/vendor.js:661409:15)
at applyPlatformOverrides (http://localhost:9876/_karma_webpack_/vendor.js:661428:63)
at TestBedImpl. (http://localhost:9876/_karma_webpack_/vendor.js:661465:136)
at TestBedImpl. (http://localhost:9876/_karma_webpack_/vendor.js:661016:88)
at UserContext. (http://localhost:9876/_karma_webpack_/main.js:204:64)
at _ZoneDelegate.invoke (http://localhost:9876/_karma_webpack_/polyfills.js:29173:158)
at ProxyZoneSpec.onInvoke (http://localhost:9876/_karma_webpack_/vendor.js:521203:33)

[satanTime]

I've checked this against the current Angular 21 setup in the repo and I can't reproduce it anymore.

Using the repo wrappers:

• sh compose.sh root
• sh compose.sh a21
• sh test.sh a21

the Angular 21 suite passes without the TestModule ... without Angular decorators error.

So this looks fixed by the current Angular 21 support work, not by the older PR #12594, but by the newer official Angular 21 support PR #13295.

My guess is that your project is still using an older/custom Angular 21 test bootstrap, and that is what triggers the problem.

After the next release this issue should be gone. If it still happens then, please share a minimal repro, especially your test.ts / initTestEnvironment(...) setup.

[zrusev]

I my case: after updating to the proposed fix, I still got the same error message. But after migrating to Angular's new building system I got everthing working as expected.