__mocks__axios.ts

const axios = {
  get: jest.fn(() => Promise.resolve({ data: {} })),
  post: jest.fn(() => Promise.resolve({ data: {} })),
  put: jest.fn(() => Promise.resolve({ data: {} })),
  create: jest.fn(() => axios),
  defaults: {
    adapter: {},
  },
}

export default axios

AxiosClient.test.tsx

import mockAxios from 'axios'

import AxiosClient from '../../src/Clients/AxiosClient'

describe('AxiosClient', () => {
  test('calls axios.create on new instance', done => {
    new AxiosClient({})

    expect(mockAxios.create).toBeCalled()
    done()
  })

  describe('AxiosClient mocked', () => {
    test('on GET request, calls get() from axios correctly', done => {
      const req = { url: '/', params: { test: 1234 } }

      const client = new AxiosClient({})
      client.get = jest
        .fn()
        .mockImplementationOnce(({ url, params }) =>
          mockAxios.get(url, { params })
        )

      client.get(req)

      expect(client.get).toBeCalled()
      expect(client.get).toBeCalledWith({
        url: req.url,
        params: req.params,
      })
      expect(mockAxios.create).toBeCalled()
      expect(mockAxios.get).toBeCalled()
      expect(mockAxios.get).toBeCalledWith(req.url, { params: req.params })
      done()
    })

    test('on POST request, calls post() from axios correctly', done => {
      const req = { url: '/', data: { test: 1234 } }

      const client = new AxiosClient({})
      client.post = jest
        .fn()
        .mockImplementationOnce(({ url, data }) => mockAxios.post(url, { data }))

      client.post(req)

      expect(client.post).toBeCalled()
      expect(client.post).toBeCalledWith({
        url: req.url,
        data: req.data,
      })
      expect(mockAxios.create).toBeCalled()
      expect(mockAxios.post).toBeCalled()
      expect(mockAxios.post).toBeCalledWith(req.url, { data: req.data })
      done()
    })

    test('on PUT request, calls put() from axios correctly', done => {
      const req = { url: '/', data: { test: 1234 } }

      const client = new AxiosClient({})
      client.put = jest
        .fn()
        .mockImplementationOnce(({ url, data }) => mockAxios.put(url, { data }))

      client.put(req)

      expect(client.put).toBeCalled()
      expect(client.put).toBeCalledWith({
        url: req.url,
        data: req.data,
      })
      expect(mockAxios.create).toBeCalled()
      expect(mockAxios.put).toBeCalled()
      expect(mockAxios.put).toBeCalledWith(req.url, { data: req.data })
      done()
    })
  })

  describe('AxiosClient straight', () => {
    test('on GET request, calls get() from axios correctly', done => {
      const req = { url: '/', params: { test: 1234 } }

      const client = new AxiosClient({})
      client.get(req)

      expect(mockAxios.create).toBeCalled()
      expect(mockAxios.get).toBeCalled()
      expect(mockAxios.get).toBeCalledWith(req.url, { params: req.params })
      done()
    })

    test('on POST request, calls post() from axios correctly', done => {
      const req = { url: '/', data: { test: 1234 } }

      const client = new AxiosClient({})
      client.post(req)

      expect(mockAxios.create).toBeCalled()
      expect(mockAxios.post).toBeCalled()
      expect(mockAxios.post).toBeCalledWith(req.url, { data: req.data })
      done()
    })

    test('on PUT request, calls put() from axios correctly', done => {
      const req = { url: '/', data: { test: 1234 } }

      const client = new AxiosClient({})
      client.put(req)

      expect(mockAxios.create).toBeCalled()
      expect(mockAxios.put).toBeCalled()
      expect(mockAxios.put).toBeCalledWith(req.url, { data: req.data })
      done()
    })
  })
})

AxiosClient.ts

import axios, { AxiosInstance, AxiosPromise, AxiosRequestConfig } from 'axios'

import HttpRequestClient from '../Interfaces/HttpRequestClient'

class AxiosClient implements HttpRequestClient {
  private engine: AxiosInstance

  constructor(requestConfig: AxiosRequestConfig = {}) {
    this.engine = axios.create(requestConfig)
  }

  get({ url, params = {} }: { url: string; params?: any }): AxiosPromise {
    return this.engine.get(url, { params })
  }

  post({ url, data = {} }: { url: string; data?: any }): AxiosPromise {
    return this.engine.post(url, { ...data })
  }

  put({ url, data = {} }: { url: string; data?: any }): AxiosPromise {
    return this.engine.put(url, { ...data })
  }
}

export default AxiosClient

coverage

----------------------------------|----------|----------|----------|----------|-------------------|
File                              |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
----------------------------------|----------|----------|----------|----------|-------------------|
All files                         |      100 |       75 |      100 |      100 |                   |
 Clients                          |      100 |       25 |      100 |      100 |                   |
  AxiosClient.ts                  |      100 |       25 |      100 |      100 |           8,16,20 |Orange
 Controllers                      |      100 |      100 |      100 |      100 |                   |
  LeadsController.ts              |      100 |      100 |      100 |      100 |                   |
  MailingController.ts            |      100 |      100 |      100 |      100 |                   |
 Exceptions                       |      100 |      100 |      100 |      100 |                   |
  MissingParameterException.ts    |      100 |      100 |      100 |      100 |                   |
 Factories                        |      100 |      100 |      100 |      100 |                   |
  ErrorFactory.ts                 |      100 |      100 |      100 |      100 |                   |
  ResponseFactory.ts              |      100 |      100 |      100 |      100 |                   |
 Guards                           |      100 |      100 |      100 |      100 |                   |
  GuardAgainstMissingParameter.ts |      100 |      100 |      100 |      100 |                   |
 Helpers                          |      100 |      100 |      100 |      100 |                   |
  regexp.ts                       |      100 |      100 |      100 |      100 |                   |
 Models                           |      100 |      100 |      100 |      100 |                   |
  LeadsModel.ts                   |      100 |      100 |      100 |      100 |                   |
  MailchimpModel.ts               |      100 |      100 |      100 |      100 |                   |
 Transformers                     |      100 |      100 |      100 |      100 |                   |
  BodyParserTransformer.ts        |      100 |      100 |      100 |      100 |                   |
  LeadCreationTransformer.ts      |      100 |      100 |      100 |      100 |                   |
  MailchimpTransformer.ts         |      100 |      100 |      100 |      100 |                   |
 ValidationSchemas                |      100 |      100 |      100 |      100 |                   |
  LeadCreationSchema.ts           |      100 |      100 |      100 |      100 |                   |
 Validators                       |      100 |      100 |      100 |      100 |                   |
  DataValidator.ts                |      100 |      100 |      100 |      100 |                   |
----------------------------------|----------|----------|----------|----------|-------------------|

HttpRequestClient.ts

interface HttpRequestClient {
  get: ({ url, params }: { url: string; params?: any }) => Promise<any>
  post: ({ url, data }: { url: string; data?: any }) => Promise<any>
  put: ({ url, data }: { url: string; data?: any }) => Promise<any>
}

export default HttpRequestClient