How to use buildArgv method in Jest

Just use mockObject.calls. In my case I used:

const call = mockUpload.mock.calls[0][0]

Here's the documentation about the mock property

If you have configured everything correctly just do

test('renders properly', () => {
  const wrapper = shallow(<component.Template>test</component.Template>);
  expect(wrapper).toMatchSnapshot();
});

This should work as expected.

while jest can run async code easily, you can use promise and setTimeout combination to wait a bit. For example this code will wait for 2 seconds:

await new Promise((r) => setTimeout(r, 2000));

Full sample test. Don't forget to add async flag before the callback function:

test('some test title', async () => {
  const foo = true;
  await new Promise((r) => setTimeout(r, 2000));
  expect(foo).toBeDefined();
});

Also, keep in mind that default "timeout" is 5 seconds (5000ms). If your test may run longer, you can add jest.setTimeout(30000); above the test(). 30000 will make sure to not timeout for 30 seconds. You can add any number you need. Full example with setTimeout:

jest.setTimeout(30000);

test('some test title', async () => {
  const foo = true;
  await new Promise((r) => setTimeout(r, 2000));
  expect(foo).toBeDefined();
});

You're using "@testing-library/jest-dom/extend-expect" which provides a set of custom jest matchers that you can use, fore example you have toHaveTextContent(text: string | RegExp, options?: {normalizeWhitespace: boolean}) that you can use here:

const checkContent = screen.getByTestId("title-content");
expect(checkContent).toHaveTextContent("Dashboard Menu");

You have stubbed the function with one that does not return anything. FirstComponent.sayMyName = jest.fn();

To test the function, typically you can just do

// if static etc
import { sayMyName } from '../foo/bar';

describe('bar', () => {
  it('should do what I like', () => {
    expect(sayMyName('orange')).toMatchSnapshot();
  });
})

This will store the output ("orange") and assert that every time you run this test, it should return orange. If your function stops doing that or returns something else, snapshot will differ and test will fail.

the direct comparison .toBe('orange') will still be possible but the really useful thing about jest is snapshot testing so you don't need to duplicate logic and serialise/deep compare structures or jsx.

if it's a component method, you need to render it first, getInstance() and then call it.

Try with this jest.config.js:

module.exports = {
  testEnvironment: "node",
  globalSetup: '<rootDir>/src/testSetup.ts'
};

And in testSetup.ts you can do:

// testSetup.ts
module.exports = async () => {
    const app = require("../../app");
    server = http.createServer(app);
    server.listen(done);
};

Jest will terminate after one assertion fails. This is to support the idea that a test should assert exactly one thing. It's not necessarily bad to have multiple related assertions in a single test, but if your unit test tests a single piece of functionality and one assertion fails, it doesn't really matter if the others are correct or not. If you need to figure out what's wrong with your test result, just debug or console.log concreteScopes.

With Jest 24.3.0 or higher, you can do this in pure TypeScript by adding the following to a Jest setup file configured in setupFilesAfterEnv:

import { CustomConsole, LogType, LogMessage } from '@jest/console';

function simpleFormatter(type: LogType, message: LogMessage): string {
    const TITLE_INDENT = '    ';
    const CONSOLE_INDENT = TITLE_INDENT + '  ';

    return message
        .split(/\n/)
        .map(line => CONSOLE_INDENT + line)
        .join('\n');
}

global.console = new CustomConsole(process.stdout, process.stderr, simpleFormatter);

I'm afraid I am not familiar with the Apollo library but it looks to me like the mock is not working; instead it is attempting a real http call to localhost:80.

I expect that the reason you don't see the error when you don't 'await' is because the http request itself is asynchronous so it does not get a chance to run before you do the assertion if there is no 'await' in the test.

Looking at the code I surmise that you are prepopulating a cache with data so it should not attempt network access? I suggest stepping through the 'mount' function or hook with a debugger and try to see if the mock data is ending up where you expect it to be. I have often got confused with java script values not ending up where I expect!

Sorry I couldn't be more help.