Simulate asynchronous function in imported module

Is it possible to monitor the behavior of an asynchronous function in a module that has been imported?

jest.mock('snowflake-promise');
import { Snowflake } from 'snowflake-promise';

describe('Snowflake', () => {
    let snowflakeMocked: any;

    beforeEach(async () => {
        snowflakeMocked = Snowflake as jest.Mocked<typeof Snowflake>;         
    });

    test('Investigating Snowflake...', async () => {
        jest.spyOn(Snowflake, 'execute').mockResolvedValue(new Promise<void>());


An error occurs with the argument '"execute"' and cannot be assigned to parameter of type 'never'.

"snowflake-promise": "^4.2.0",
typescriptunit-testingjestjsmockingts-jest

Answer №1

import { Snowflake } from 'snowflake-promise';
import { mockDeep } from 'jest-mock-extended';

describe('Testing Snowflake library', () => {
    let snowflakeMocked: DeepMockProxy<Snowflake>;

    beforeEach(async () => {
        snowflakeMocked = mockDeep<Snowflake>();         
    });

    test('Checking if Snowflake executes correctly', async () => {
        snowflakeMocked.execute.mockResolvedValue(Promise<void>.resolve());
    });
}

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