Tips for creating Angular unit tests that involve setting @Input values and mocking them

As a beginner in Angular, I am currently diving into writing test cases. How can I approach writing unit tests for the following code snippet in Angular/TypeScript?

@Input() set myOutputData(res: any) {
        this.apiError = '';
        if (!res) {
            this.myTableData = {
                opt: [],
                firstSummary: { netSummary: [], new_summary: '' },
                secondSummary: { netSummary: [], new_summary: '' },
                cost: 0
            };
            return;
        } else if (res && Object.keys(res).length === 0) {
            this.myTableData = {
                opt: [],
                firstSummary: { netSummary: [], new_summary: '' },
                secondSummary: { netSummary: [], new_summary: '' },
                cost: 0
            };
            return;
        } else if (this.errorTable) {
            const msg = 'message';
            this.apiError = this.errorTable;
            this.localError = this.apiError;
            this.myTableData = {
                opt: [],
                firstSummary: { netSummary: [], new_summary: '' },
                secondSummary: { netSummary: [], new_summary: '' },
                cost: 0
            };
            return;
        } else {
            this.myTableData = res;
        }
}

Answer №1

One way to test your component is by creating a TestComponent where you can call the component you want to test and pass input properties.

For example:

@Component({
  template: '<your-component [myInputData]="myInputData"></your-component>'
})
export class TestComponent{    
  myInputData = <value to be passed>    
}

Next, write test cases for the TestComponent where you can access your component using ViewChild and perform tests as needed.

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