Question 116580 in Mongodb Question posted in
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Mongodb – Jest test times out, manual test works fine

I’m trying to test a nodejs function using Jest. I’m a complete beginner in Jest, so I assume this is a problem in the way I have structured my tests.

When called manually or from within the application, the function works fine. But when called from a Jest test, it either times out, returns an empty object or otherwise falls over.

The function to be tested:

async function createUser(username, password){
    try{
        const user = await UserModel.create({ username, password });
        return true;
    } catch(error){
        if(error.code == 11000){
            const field = Object.keys(error.keyValue);
            const err = Error("Account with username " + field + " already exists");
            throw err;
        }
        if(error.name == 'ValidationError'){
            const err = Error("Error creating new user");
            throw err;
        }
        const err = Error("Unknown error creating new user");
        throw err;
    }
}

and the Jest tests I have created:

test('createUser: Non empty input should create account and return true', async () => {
    const data = await register.createUser('johnsmith1', 'smithjohn');
    expect(data).toBe(true);
});

test('createUser: Duplicate user/pass should not create user and should throw error', async () => {
    try{
        await register.createUser('johnsmith1', 'smithjohn');
    } catch(error){
        expect(error).toMatch('error');
    }
});

When run both tests timeout:

createUser: Duplicate user/pass should not create user and should throw error

    thrown: "Exceeded timeout of 5000 ms for a test.
    Use jest.setTimeout(newTimeout) to increase the timeout value, if this is a long-running test."

      74 | });
      75 |
    > 76 | test('createUser: Duplicate user/pass should not create user and should throw error', async () => {
         | ^
      77 |     try{
      78 |         await register.createUser('johnsmith1', 'smithjohn');
      79 |     } catch(error){

      at Object.test (tests/register.test.js:76:1)
Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    Thanks to Marek Rozmus.

    The solution was that I needed to use mocks to return dummy data instead of using a call to mongoose.

    After mocking the calls, the tests worked as expected. Also learned about formulating better tests - we're not testing mongoose, only whether our code can handle what mongoose might return (success, error, timeout etc.)


  2. 0

    Your createUser takes more than 5 seconds, which is the default timeout in jest.

    In order to increase the timeout only for a single test, as a third param to the test function.

    More info here: jset setTimeout per test

    test('createUser: Non empty input should create account and return true', async () => {
    const data = await register.createUser('johnsmith1', 'smithjohn');
    expect(data).toBe(true);
}, 10000); // Jest will wait 10000 ms

    In order to increase the timeout globally, you can read this

    configure-jest-timeout-once-for-all-tests

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