slack-jest-example.js

describe('welcomeInstallHandler', () => {
    it('sends welcome msg', () => {
        const msgMock = jest.fn().mockResolvedValue(null);
        SlackClient.mockImplementation(() => {
            return {
                say: msgMock,
            };
        });
        const event = {
            slackWorkspace: {
                incoming_webhook: {
                    channel_id: Math.random(),
                },
            },
        };
        const msg = {
            attachments: [{
                actions: [{
                    name: 'settings_command',
                    text: 'Settings',
                    type: 'button',
                    value: 'settings',
                }],
                callback_id: 'welcome_callback',
                fallback: 'Checkout out all the latest features with /eletype help!',
                text: ':wave: Let\'s get started! First, I need to get some information from you. ' +
                'Please click the Settings button below to continue.',
                title: 'Welcome!',
            }],
            channel: event.slackWorkspace.incoming_webhook.channel_id,
            text: '',
        };
        return responder.welcomeInstallHandler(event).then(() => {
            expect(msgMock).toBeCalledWith(msg);
        });
    });
});