CODEWITHSUNDEEP
angulartypescriptkarma-jasmine
David Angarita
David Angarita

Reputation: 910

TypeError: Cannot read properties of undefined (reading 'filter') at <Jasmine>

I am creating a test for clear Item, but when I run the test I get the error of "TypeError: Cannot read properties of undefined (reading 'filter') at "

How can I arrange to run filter in the test?

My function:

clearItem = (item, key) => {
        this.form[key] = this.form[key].filter(el => el !== item);
        this.chipsOptions = this.chipsOptions.filter(el => el !== item);
    }

My test:

describe('clearItem()', () => {
        it('should clear item', () => {
            let item = {id:1, name:'test'};
            component.form = { key: {id:1}, id: 1, name: 'testForm' };

            component.addItem(item);
            component.clearItem(item, {key: { id: 1 }});

            expect(component.form['key']).not.toEqual(item);
            expect(component.chipsOptions['key']).not.toEqual(item);
        });
    });

Upvotes: 0

Views: 28482

Answers (1)

Mohammad Karimi
Mohammad Karimi

Reputation: 121

The filter method is defined for array objects. Before using filter method, try to check the types of objects that you use this method.

console.log(Array.isArray(this.form[key]));
console.log(Array.isArray(this.chipsOptions));
// When both of them are true, then you can use filter.

filter method reference

isArray method reference

Upvotes: 2

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