ng2-pipes/src/app/pipes/array/filter-by.spec.ts

Useful angular2 pipes

import {FilterByPipe} from './filter-by';

describe('FilterByPipe', () => {
  let pipe: FilterByPipe;

  const users = [
    {id: 1, first_name: 'John', last_name: 'Doe', work: { title: 'Software Engineer', company: 'Foo Tech', previous_company: 'Unknown' }},
    {id: 2, first_name: 'Jane', last_name: 'West', work: { title: 'Designer', company: 'AAA Solutions', previous_company: 'Unknown' }},
    {id: 3, first_name: 'Bruce', last_name: 'John', work: { title: 'Software Engineer', company: 'Bar Tech', previous_company: 'Unknown' }},
    {id: 4, first_name: 'William', last_name: 'Cent', work: { title: 'Designer', company: 'Foo Tech', previous_company: 'Bar Tech' }}
  ];

  beforeEach(() => {
    pipe = new FilterByPipe();
  });

  it('should not do anything in-case of not an array', () => {
    expect(pipe.transform('foo', [''], '')).toEqual('foo');
    expect(pipe.transform(null, [''], '')).toEqual(null);
    expect(pipe.transform(undefined, [''], '')).toEqual(undefined);
    expect(pipe.transform(42, [''], '')).toEqual(42);
    expect(pipe.transform({foo: 1, bar: 2}, [''], '')).toEqual({foo: 1, bar: 2});
  });

  it('should filter by single field with a single result', () => {
    const filtered = pipe.transform(users, ['id'], 1);

    expect(filtered.length).toEqual(1);
    expect(filtered[0]).toEqual(users[0]);
  });

  it('should filter by multiple fields with a two result', () => {
    const filtered = pipe.transform(users, ['first_name', 'last_name'], 'John');

    expect(filtered.length).toEqual(2);
    expect(filtered[0]).toEqual(users[0]);
    expect(filtered[1]).toEqual(users[2]);
  });

  it('should filter by nested field with a single result', () => {
    const filtered = pipe.transform(users, ['work.company'], 'Bar');

    expect(filtered.length).toEqual(1);
    expect(filtered[0]).toEqual(users[2]);
  });

  it('should filter by nested field with a multiple result', () => {
    const filtered = pipe.transform(users, ['work.title'], 'Designer');

    expect(filtered.length).toEqual(2);
    expect(filtered[0]).toEqual(users[1]);
    expect(filtered[1]).toEqual(users[3]);
  });

  it('should filter by multiple nested field with a multiple result', () => {
    const filtered = pipe.transform(users, ['work.company', 'work.previous_company'], 'Bar Tech');

    expect(filtered.length).toEqual(2);
    expect(filtered[0]).toEqual(users[2]);
    expect(filtered[1]).toEqual(users[3]);
  });

  it('should filter by field with a strict mode', () => {
    const filtered = pipe.transform(users, ['work.company'], 'Bar', true);

    expect(filtered.length).toEqual(0);
  });
});