app_vue2/tests/unit/services/connection/connection.spec.ts

import Connection from "~/services/connection/connection";
import axios from "~/plugins/Data/axios";
import {HTTP_METHOD, QUERY_TYPE} from "~/types/enums";
import {NuxtAxiosInstance} from "@nuxtjs/axios";

let $connection:any
const axiosMock = axios as jest.Mocked<NuxtAxiosInstance>;

beforeAll(()=>{
  $connection = new Connection()
  Connection.initConnector(axiosMock)
})

describe('invoke()', () => {

  it('should throw an error if the method is unknown', ()=>{
    expect( () => $connection.invoke('GETS', 'users', {type: QUERY_TYPE.MODEL})).toThrow()
  })

  describe('getItem()',  () => {
    it('should return item data', async()=>{
      Connection.connector.$request = jest.fn().mockReturnValue({data: 'data user 1'})
      const response = await $connection.invoke(HTTP_METHOD.GET, 'users', {type: QUERY_TYPE.MODEL})
      expect(response).toStrictEqual({data: 'data user 1'})
    })

    it('should call getItem', async()=>{
      $connection.getItem =  jest.fn().mockReturnValue({})
      await $connection.invoke(HTTP_METHOD.GET, 'users', {type: QUERY_TYPE.MODEL, id: 1})
      expect($connection.getItem).toHaveBeenCalled();
    })
  })

  describe('getCollection()',  () => {
    it('should return collection data', async()=>{
      Connection.connector.$request = jest.fn().mockReturnValue([{data: 'data user 1'}, {data: 'data user 2'}])
      const response = await $connection.invoke(HTTP_METHOD.GET, 'users', {type: QUERY_TYPE.MODEL})
      expect(response).toStrictEqual([{data: 'data user 1'}, {data: 'data user 2'}])
    })
    it('should call getCollection and return collection data', async () => {
      $connection.getCollection =  jest.fn().mockReturnValue({})
      await $connection.invoke(HTTP_METHOD.GET, 'users', {type: QUERY_TYPE.MODEL})
      expect($connection.getCollection).toHaveBeenCalled();
    })
  })

  describe('put()',  () => {
    it('should throw an error if data missing', async() => {
      expect( () => $connection.invoke(HTTP_METHOD.PUT, 'users', {type: QUERY_TYPE.MODEL})).toThrow()
    })

    it('should return item data', async()=>{
      Connection.connector.$request = jest.fn().mockReturnValue({data: 'data user 1'})
      const response = await $connection.invoke(HTTP_METHOD.PUT, 'users', {type: QUERY_TYPE.MODEL, id: 1, data:{}})
      expect(response).toStrictEqual({data: 'data user 1'})
    })

    it('should call put and return item data', async()=>{
      $connection.put =  jest.fn().mockReturnValue({})
      await $connection.invoke(HTTP_METHOD.PUT, 'users', {type: QUERY_TYPE.MODEL, id: 1, data:{}})
      expect($connection.put).toHaveBeenCalled();
    })
  })

  describe('deleteItem()',  () => {
    it('should delete item', async()=>{
      Connection.connector.$request = jest.fn().mockReturnValue({})
      const response = await $connection.invoke(HTTP_METHOD.DELETE, 'users', {type: QUERY_TYPE.MODEL, id: 1})
      expect(response).toStrictEqual({})
    })

    it('should call deleteItem', async()=>{
      $connection.deleteItem =  jest.fn().mockReturnValue({})
      await $connection.invoke(HTTP_METHOD.DELETE, 'users', {type: QUERY_TYPE.MODEL, id: 1})
      expect($connection.deleteItem).toHaveBeenCalled();
    })
  })

})