Manual PromiseMock

Unit tests mocks made easy!

npm install manual-promise-mock --save-dev

Main features

• Fully synchronous operations
• Abillity to step through the Promise's execution chain
• Abillity to mock the execution chain's results
• Abillity to mock every step in the execution chain

Examples

Make the Promise synchronous:

import { PromiseMock } from 'manual-promise-mock';

const syncPromise = PromiseMock.resolve({ mock: 'first-one!' });

syncPromise
    .then(rs => {
        console.log(rs); // { mock: 'first-one!' }
        return 42;
    })
    .then(rs => {
        console.log(rs); // 42
    });

Make the Promise synchronous and mock the execution chain's results:

import { PromiseMock } from 'manual-promise-mock';

const syncPromiseMocks = PromiseMock.resolve(null, [
    { mock: 'first-one!' },
    { mock: 'second-one!' },
    { mock: 'catch-me!' },
]);

syncPromiseMocks
    .then(rs => {
        console.log(rs); // { mock: 'first-one!' }
    })
    .then(rs => {
        console.log(rs); // { mock: 'second-one!' }
        throw new Error('Oh, no!');
    })
    .catch(rs => {
        console.log(result); // { mock: 'catch-me!' }
    });

Stepping through the Promise's execution chain:

import { PromiseMockStep } from 'manual-promise-mock';

const stepPromise = new PromiseMockStep.resolve({mock: 'data'});

stepPromise
    .then(rs => {
        console.log('First then:', rs);
        throw new Error('Thrown from first then.')
    })
    .then(rs => {
        console.log('Second then:', rs);
    })
    .catch(err => {
        console.log('First catch:', err.message);
        return 'feed next callback';
    })
    .finally(who => {
        console.log(`Finally comes last!\r\n-${who} 2020`);
    })
    .catch(err => {
        console.log('Second catch:', err.message);
    })
    .then(rs => {
        console.log('Third then:', rs);
    })
    .then(rs => {
        console.log('Last then:', rs);
    });

stepPromise.next(); // First then: { mock: 'data' }
stepPromise.next(); // First catch: Thrown from first then.
stepPromise.next(); // Third then: feed next callback
stepPromise.next({ swapData: true }); // Last then: { swapData: true }
stepPromise.next('Socrates'); // Finally comes last! -Socrates 2020