How to implement guide with mocking external apis in unit tests using jest for a node.js app
I'm not sure how to approach I'm relatively new to this, so bear with me. I tried several approaches but none seem to work. I'm working with a scenario while trying to mock an external API call in my unit tests using Jest for a Node.js application. The function I'm testing is supposed to fetch data from an external API and return the response. Here's a simplified version of my function: ```javascript const axios = require('axios'); async function fetchData(url) { const response = await axios.get(url); return response.data; } ``` In my test file, I'm attempting to mock the `axios.get` method to avoid making actual network calls. Here’s how I’m currently setting up my test: ```javascript const fetchData = require('./fetchData'); const axios = require('axios'); jest.mock('axios'); test('fetches successfully data from an API', async () => { const data = { data: 'some data' }; axios.get.mockResolvedValue(data); const result = await fetchData('https://api.example.com/data'); expect(result).toEqual('some data'); }); ``` However, I'm getting the following behavior when I run the tests: ``` behavior: Expectation failed: expected 'some data' to equal [object Object]. ``` It seems that `mockResolvedValue` is returning an object that I didn't expect. I've tried changing the mock to return just the data directly, but that didn’t resolve the scenario. I also checked that the Jest version I'm using is 27.0.6, and I’ve ensured that axios is installed at version 0.21.1. Can someone guide to understand why this is happening? What am I missing in the mock setup? I'm eager to learn the best practices for mocking external API calls in unit tests using Jest. Any ideas what could be causing this? This is part of a larger application I'm building.