bug(aria/listbox): Error in tests when using Listbox as a HostDirective (Cannot access 'ComboboxPopup' before initialization)

[makmn1]

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

An error occurs when trying to test a component which uses Listbox as a host directive

Note: This problem only occurs when running tests in Angular v21 with ng test. There are no errors when running ng serve and the component works with Listbox as expected.

Reproduction

Minimal reproduction repo: https://github.com/makmn1/angular-aria-listbox-initialization-bug

I could not reproduce my issue on StackBlitz because there are issues with running tests in StackBlitz with JSDOM. I was getting the following error when running ng test after upgrading to Angular v21 (the default in StackBlitz is 20):

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Unhandled Errors ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

Vitest caught 1 unhandled error during the test run.
This might cause false positive tests. Resolve unhandled errors to make sure your tests are not affected.

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Unhandled Error ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
TypeError: Object.defineProperty called on non-object
 ❯ _0x1b8008 ../../../blitz.cf284e50.js:31:858920
 ❯ Object.createContext ../../../builtins.97a3df4f.js:322:3356
 ❯ exports.createWindow node_modules/jsdom/lib/jsdom/browser/Window.js#cjs:82:17
 ❯ new JSDOM node_modules/jsdom/lib/api.js#cjs:36:20
 ❯ Object.setup node_modules/vitest/dist/chunks/index.BspFP3mn.js:526:15
 ❯ Object.setupEnvironment [as setup] node_modules/vitest/dist/chunks/base.BEv8sRbK.js:140:14
 ❯ _0xf8839a.onMessage node_modules/vitest/dist/chunks/init.a5SCIJ0x.js:199:23

Expected Behavior

The ability to test a component that has Listbox as a hostDirective

Actual Behavior

Adding the Listbox directive to the hostDirectives list for a component and then running ng test in an Angular v21 project using Vitest + JSDOM results in the following error:

ReferenceError: Cannot access 'ComboboxPopup' before initialization
 ❯ Combobox.<static_initializer> node_modules/@angular/aria/fesm2022/combobox.mjs:147:18
 ❯ node_modules/@angular/aria/fesm2022/combobox.mjs:1:1
 ❯ src/app/listbox-host/listbox-host.component.ts:2:1

That's from the reproduction link above. In my project which uses Vitest with Playwright instead of JSDOM, I got a vague error:

Error: Failed to import test file C:/Users/makmn/IdeaProjects/simply-material/simply-material/projects/components/src/lib/buttons/button-group/button-group-selection.spec.ts
Caused by: TypeError: Cannot read properties of undefined (reading 'directive')
 ❯ <static_initializer> spec-button-group-selection.js:845:42

Environment

Item	Version
Angular CLI	21.0.0
Angular	21.0.1
Node.js	24.11.0
Package Manager	npm 11.6.1
Operating System	win32 x64

Package	Installed Version	Requested Version
@angular/aria	21.0.0	^21.0.0
@angular/build	21.0.0	^21.0.0
@angular/cli	21.0.0	^21.0.0
@angular/common	21.0.1	^21.0.0
@angular/compiler	21.0.1	^21.0.0
@angular/compiler-cli	21.0.1	^21.0.0
@angular/core	21.0.1	^21.0.0
@angular/forms	21.0.1	^21.0.0
@angular/platform-browser	21.0.1	^21.0.0
@angular/platform-server	21.0.1	^21.0.0
@angular/router	21.0.1	^21.0.0
@angular/ssr	21.0.0	^21.0.0
rxjs	7.8.2	~7.8.0
typescript	5.9.3	~5.9.2
vitest	4.0.14	^4.0.8

[makmn1]

Thanks for fixing this. I want to clear up that other error I was seeing in case someone runs into it:

Error: Failed to import test file C:/Users/makmn/IdeaProjects/simply-material/simply-material/projects/components/src/lib/buttons/button-group/button-group-selection.spec.ts
Caused by: TypeError: Cannot read properties of undefined (reading 'directive')
 ❯ <static_initializer> spec-button-group-selection.js:845:42

That was actually unrelated to this error. It was an issue on my end caused by how I imported files into my tests. I was importing from my public API exports (i.e. barrel file) instead of directly from the file I needed. Changing that to directly import from the file under test removed that error.