How can i test this function in Angular 2-CodePudding

moveColumns(shifter: number, index: number) {
    const columnFields = this.form.get('sizes') as FormArray;
 
    let newIndex = index   shifter;
    if (newIndex === -1) {
      newIndex = columnFields.length - 1;
    } else if (newIndex === columnFields.length) {
      newIndex = 0;
    }
 
    const currentGroup = columnFields.at(index);
    columnFields.removeAt(index);
    columnFields.insert(newIndex, currentGroup);
  }

My dificculty is that they are all inside function variables and not component global variables.

CodePudding user response：

You need to stub the form object and then validate the changes that happen in the function

// in your test beforeEach
mockComponent.form = new FormArray({sizes: new FormControl());

// And in your function, you can update this form object and validate it

it('should test my function', () => {
const modifiedForm = {} // Add the final result after the function executes

expect(mockComponent.form).toEquals(modifiedForm);
})