How can i globally mock lodash/deep function in jest - jestjs

Question

I am using lodash/deep function in the controller. While performing jest test for the controller it gives the following error:
All of the lodash functions gives errors.
TypeError: cloneDeep_1.default is not a function.
sample code below
import cloneDeep from 'lodash/cloneDeep'
static transformBoardBasicInfo (rawBoard:any): any {
const clonedBoard: any = cloneDeep(rawBoard) as any
clonedBoard.info = this.getInfo(rawBoard)
return clonedBoard
}

Answer 1

I suppose you want to add a spy on cloneDeep function. But it's unnecessary, cloneDeep function is a pure function and doesn't call any side-effected external services. So you don't need to mock or make a stub for it.
index.ts:
import cloneDeep from 'lodash/cloneDeep';
export class SomeClass {
public static transformBoardBasicInfo(rawBoard: any): any {
const clonedBoard: any = cloneDeep(rawBoard) as any;
clonedBoard.info = this.getInfo(rawBoard);
return clonedBoard;
}
public static getInfo(board) {
return '';
}
}
index.spec.ts:
import { SomeClass } from './';
import cloneDeep from 'lodash/cloneDeep';
jest.mock('lodash/cloneDeep', () => jest.fn());
describe('main', () => {
afterEach(() => {
jest.restoreAllMocks();
jest.resetAllMocks();
});
it('should pass', () => {
jest.spyOn(SomeClass, 'getInfo');
(cloneDeep as any).mockImplementationOnce((data) => {
return require.requireActual('lodash/cloneDeep')(data);
});
const mRawBoard = { info: '123' };
const actual = SomeClass.transformBoardBasicInfo(mRawBoard);
expect(actual).toEqual({ info: '' });
expect(cloneDeep).toBeCalledWith(mRawBoard);
expect(SomeClass.getInfo).toBeCalledWith(mRawBoard);
});
});
Unit test result with coverage report:
PASS src/stackoverflow/59298693/index.spec.ts
main
✓ should pass (25ms)
----------|----------|----------|----------|----------|-------------------|
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files | 100 | 100 | 100 | 100 | |
index.ts | 100 | 100 | 100 | 100 | |
----------|----------|----------|----------|----------|-------------------|
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 5.075s, estimated 12s