如何在Angular 4规格文件中模拟nativeElement.focus() [英] How to mock a nativeElement.focus() in Angular 4 spec file

问题描述

我有一种使用下面定义的 ElementRef 的方法.

I have a method which uses an ElementRef which is defined below.

@ViewChild('idNaicsRef') idNaicsRef: ElementRef;

然后

ElementRef 使用 .nativeElement.focus()设置焦点.

该方法在运行规范时失败，提示未定义是对象"

The method fails while running the spec, saying 'undefined is an object'

推荐答案

这应该有效.这只会创建一个间谍对象，然后您可以使用所需的任何对象填充它，因此甚至可以检查它是否在单元测试中被调用.

this should work. this just creates a spy object and then you can populate it with whatever you want, so you could even check if it was called in your unit test.

  import createSpyObj = jasmine.createSpyObj;
  comp.idNaicsRef = createSpyObj('idNaicsRef', ['nativeElement']);
  comp.idNaicsRef.nativeElement = { focus: () => { }};

comp 是对要测试的组件的引用.

comp is the reference to the component you are testing.

createSpyObj 来自茉莉花导入

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