之前我们测试了 headers 的基础方法模块，接下来我们会从业务角度测试 headers 的相关业务逻辑。

测试代码编写

test/headers.spec.ts：

  1. import axios from '../src/index'
  2. import { getAjaxRequest } from './helper'
  4. function testHeaderValue(headers: any, key: string, val?: string): void {
  5.   let found = false
  7.   for (let k in headers) {
  8.     if (k.toLowerCase() === key.toLowerCase()) {
  9.       found = true
  10.       expect(headers[k]).toBe(val)
  11.       break
  12.     }
  13.   }
  15.   if (!found) {
  16.     if (typeof val === 'undefined') {
  17.       expect(headers.hasOwnProperty(key)).toBeFalsy()
  18.     } else {
  19.       throw new Error(key + ' was not found in headers')
  20.     }
  21.   }
  22. }
  24. describe('headers', () => {
  25.   beforeEach(() => {
  26.     jasmine.Ajax.install()
  27.   })
  29.   afterEach(() => {
  30.     jasmine.Ajax.uninstall()
  31.   })
  33.   test('should use default common headers', () => {
  34.     const headers = axios.defaults.headers.common
  36.     axios('/foo')
  38.     return getAjaxRequest().then(request => {
  39.       for (let key in headers) {
  40.         if (headers.hasOwnProperty(key)) {
  41.           expect(request.requestHeaders[key]).toEqual(headers[key])
  42.         }
  43.       }
  44.     })
  45.   })
  47.   test('should add extra headers for post', () => {
  48.     axios.post('/foo', 'fizz=buzz')
  50.     return getAjaxRequest().then(request => {
  51.       testHeaderValue(request.requestHeaders, 'Content-Type', 'application/x-www-form-urlencoded')
  52.     })
  53.   })
  55.   test('should use application/json when posting an object', () => {
  56.     axios.post('/foo/bar', {
  57.       firstName: 'foo',
  58.       lastName: 'bar'
  59.     })
  61.     return getAjaxRequest().then(request => {
  62.       testHeaderValue(request.requestHeaders, 'Content-Type', 'application/json;charset=utf-8')
  63.     })
  64.   })
  66.   test('should remove content-type if data is empty', () => {
  67.     axios.post('/foo')
  69.     return getAjaxRequest().then(request => {
  70.       testHeaderValue(request.requestHeaders, 'Content-Type', undefined)
  71.     })
  72.   })
  74.   it('should preserve content-type if data is false', () => {
  75.     axios.post('/foo', false)
  77.     return getAjaxRequest().then(request => {
  78.       testHeaderValue(request.requestHeaders, 'Content-Type', 'application/x-www-form-urlencoded')
  79.     })
  80.   })
  82.   test('should remove content-type if data is FormData', () => {
  83.     const data = new FormData()
  84.     data.append('foo', 'bar')
  86.     axios.post('/foo', data)
  88.     return getAjaxRequest().then(request => {
  89.       testHeaderValue(request.requestHeaders, 'Content-Type', undefined)
  90.     })
  91.   })
  92. })

内部定义了 testHeaderValue 辅助函数，用于测试 headers 是否存在某个 header name 下的某个值。
至此我们完成了 ts-axios 库 headers 模块相关业务逻辑的测试，下一节课我们会对 Axios 的实例做测试。