headers-polyfill/src/transformers/headersToObject.node.test.ts

A native "Headers" class polyfill.

/**
 * @jest-environment node
 */
import { headersToObject } from './headersToObject'
import { Headers } from '../Headers'

describe('given Headers with a single header', () => {
  it('should return that single header in an Object', () => {
    const headers = new Headers({ 'Content-Type': 'application/json' })
    expect(headersToObject(headers)).toEqual({
      'content-type': 'application/json',
    })
  })
})

describe('given Headers with a single header and multiple values', () => {
  it('should put that header values into an array', () => {
    const headers = new Headers({ Accept: 'application/json' })
    headers.append('Accept', 'text/plain')

    expect(headersToObject(headers)).toEqual({
      accept: ['application/json', 'text/plain'],
    })
  })
})

describe('given Headers with multiple different headers', () => {
  it('should return an object representing those headers', () => {
    const headers = new Headers({
      Accept: 'application/json',
      'Content-Length': '1234',
      'Content-Type': 'application/json',
    })
    headers.append('Accept', 'text/plain')

    expect(headersToObject(headers)).toEqual({
      accept: ['application/json', 'text/plain'],
      'content-length': '1234',
      'content-type': 'application/json',
    })
  })
})

describe('given Headers with a single header that includes a semicolon', () => {
  it('should preserve a single header', () => {
    const headers = new Headers({
      'user-agent':
        'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.0 Safari/537.36',
    })

    expect(headersToObject(headers)).toEqual({
      'user-agent':
        'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.0 Safari/537.36',
    })
  })
})