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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Dependency injection and class inheritance doesn't work in Angular 8 library test","articleBody":"# 🐞 bug report\r\n\r\n### Affected Package\r\n\r\nThe issue is caused by package @angular/core@^8\r\n\r\n### Is this a regression?\r\nYes, the previous version in which this bug was not present was: @angular/core@7\r\n\r\n\r\n### Description\r\n\r\nThe problem occurs when:\r\n\r\n1. The base class has a constructor with an injected service. (`Injector` from the example)\r\n\r\n```ts\r\n@Injectable()\r\nexport class BaseService {\r\n  // \"Injector\" is just for the sake of example. Any injectable would have the same problem.\r\n  constructor(public injector: Injector) {\r\n  }\r\n}\r\n```\r\n2. Child class has no constructor (i.e., it relies on base class constructor) AND at least one property with the default value.\r\n\r\n```ts\r\n@Injectable()\r\nexport class MyLibService extends BaseService {\r\n\r\n  public foo = 'bar';\r\n\r\n}\r\n```\r\n\r\n3. (_dont ask me how I have found this, but:_) In `angular.json` `[lib name].test.options.codeCoverage` should be true. \r\n\r\n### PROBLEM:   \r\n\r\n`injector` is undefined in the instance of `MyLibService`. \r\n\r\n--- \r\n\r\n🚩 Removing property from the child class _(2)_ AND/OR opting out `codeCoverage` config in angular.json _(3)_ doesn't brake test.\r\n\r\nAs a result, I can't have a class inheritance and code coverage at the same time.\r\n\r\n---\r\n\r\nI could put a constructor in the child class and call `super` by passing all required arguments manually, but it's the last option since the real-life scenario is much more complicated than the example provided here.\r\n\r\n## 🔬 Minimal Reproduction\r\ngit repo: https://github.com/ddramone/ng-8-library-inheritance-di-test-bug\r\n\r\nreproduce steps:\r\n\r\n1. Install angular 8 cli\r\n2. Clone `git clone https://github.com/ddramone/ng-8-library-inheritance-di-test-bug.git `\r\n3. `npm i`\r\n4. run Test `ng test my-lib`\r\n\r\n ### Expected behavior\r\n\r\nTest should pass = Injector service should be available in the service instance.","author":{"url":"https://github.com/ip7e","@type":"Person","name":"ip7e"},"datePublished":"2019-06-28T14:16:45.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":17},"url":"https://github.com/31337/angular/issues/31337"}