Unable to mock CognitoIdentityServiceProvider functions from aws-sdk in jest - reactjs

Question

Aws.config.js
import AWS from 'aws-sdk';
AWS.config.update({
region: process.env.REACT_APP_AWS_REGION,
credentials: new AWS.CognitoIdentityCredentials({
IdentityPoolId: process.env.REACT_APP_IDENTITY_POOL_ID
})
});
const AwsCognitoIdentityServiceProvider = new AWS.CognitoIdentityServiceProvider({ apiVersion: '2016-04-18' });
export default AwsCognitoIdentityServiceProvider;
I have a function in ListUser.js
import AwsCognitoIdentityServiceProvider from 'components/aws/AwsConfig';
const userList = () =>{
var params = {
UserPoolId: process.env.REACT_APP_USERPOOL_ID,
AttributesToGet: null,
Filter:""
};
AwsCognitoIdentityServiceProvider.listUsers(params,function (err, data) {
if(data) {
//fetching data here successfully
} else {
console.log("error",err);
}
})
}
My test file ListUser.test.js
const mockListUsers = jest.fn((params) => {
return {
promise() {
return Promise.resolve('mock response');
}
};
});
jest.mock('aws-sdk', () => {
return {
CognitoIdentityServiceProvider: jest.fn(() => ({
listUsers: mockListUsers
})),
config: {
update: jest.fn()
}
};
});
describe('ListUser', () => {
test('renders ListUser component', () => {
act(() => {
render(<ListUser />);
});
});
});
I am not able to mock this function and return response I am getting error below:
TypeError: _AwsConfig.default.listUsers is not a function
90 | Filter:""
91 | };
> 92 | AwsCognitoIdentityServiceProvider.listUsers(params,function (err, data) {
I have also tried with keeping aws.sdk.js file inside mocks folder but no luck
_mocks_/aws.sdk.js
class AWS {
CognitoIdentityServiceProvider = class {
listUsers = jest.fn(() =>{
return { promise: ()=> Promise.resolve({mockresponse})}
});
};
}
module.exports = AWS;
I need to mock listUsers function but not able to do so. I have followed so many links but no luck :(

Answer 1

This one works for me
const AWS = require('aws-sdk');
jest.mock('aws-sdk');
AWS.CognitoIdentityServiceProvider.prototype.listUsers = jest.fn().mockReturnValue({
promise: jest.fn().mockResolvedValue({})
});

Answer 2

I have tried this way and worked for me.
jest.mock("aws-sdk", () => {
const cognito = { listUsers: jest.fn() };
return {
CognitoIdentityServiceProvider: jest.fn(() => cognito),
config: {
update: jest.fn(),
},
};
});
const mCognitoIdentityServiceProvider = new AWS.CognitoIdentityServiceProvider();
mCognitoIdentityServiceProvider.listUsers.mockImplementationOnce(() => {
return {
promise() {
return Promise.resolve('your mock data');
},
};
});