TestBed.overrideComponent doesn't work with AOT and webpack

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#32,628 2026年2月27日に作成コメント 0 件リアクション 0 件担当者 0 名 GitHub で見る

まだ誰も着手していません。

評価

難易度: 4/5
見積もり時間: 3〜5日
初心者へのやさしさ: 45/100

issue の種類: バグ
明瞭さ: おおむね明確
活発さ: 停滞
技術スタック: angular, typescript
領域: build-system, testing-qa

調査の方向性

最小限の再現から始めます。Karma、browser mode の webpack builder、AOT を有効にした状態で、TestBed.overrideComponent または TestBed.overrideModule を使用するコンポーネントテストを作成します。application builder mode または AOT を無効にした場合の失敗と比較し、その後、影響を受ける構成で override テストが @Component メタデータが見つからないエラーなしに実行されることを確認します。

索引モデルが issue の本文から書いたものです。

説明

area: @angular-devkit/build-angular devkit/build-angular:karma freq1: low severity3: broken type: bug/fix

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

TestBed.overrideComponent and TestBed.overrideModule don't seem to work with karma, webpack builder (builderMode: browser) and aot enabled. Changing any of these settings, so builderMode: application or disabling aot "fixes" the problem. The same issue was reported here https://github.com/angular/angular-cli/issues/30017 but i guess it was only fixed for esbuild? Is there any workaround for this? or can it be fixed for angular20?

Minimal Reproduction

Create a simple valid component, turn on AOT for Karma, and make a test where you use TestBed.overrideComponent to reset metadata. You don't even need to specify an actual override in the second parameter to trigger the issue: TestBed.overrideComponent(YourComponent, {}) triggers the failure.

builderMode: browser needs to be set

Exception or Error

Error: App class doesn't have @Component decorator or is missing metadata.
            at invalidTypeError (node_modules/@angular/core/fesm2022/testing.mjs:1661:12)
            at forEach (node_modules/@angular/core/fesm2022/testing.mjs:1084:23)
            at asyncGeneratorStep (node_modules/@babel/runtime/helpers/esm/asyncToGenerator.js:3:1)
            at apply (node_modules/@babel/runtime/helpers/esm/asyncToGenerator.js:17:1)
            at _ZoneDelegate.invoke (node_modules/zone.js/fesm2015/zone.js:398:28)
            at ProxyZoneSpec.onInvoke (node_modules/zone.js/fesm2015/zone-testing.js:2132:39)

Your Environment

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


Angular CLI: 20.3.18
Node: 22.22.0
Package Manager: npm 10.9.4
OS: win32 x64


Angular: 20.3.17
... common, compiler, compiler-cli, core, forms
... platform-browser, router

Package                         Version
---------------------------------------
@angular-devkit/architect       0.2003.18
@angular-devkit/build-angular   20.3.16
@angular-devkit/core            20.3.18
@angular-devkit/schematics      20.3.18
@angular/build                  20.3.18
@angular/cli                    20.3.18
@schematics/angular             20.3.18
rxjs                            7.8.2
typescript                      5.9.3
zone.js                         0.15.1

Anything else relevant?