Does Jest swallow console.log statements? Is there a way to change this?

Question

Does Jest swallow console.log output?

// __tests__/log.test.js

it(\'logs\', () => {
  console.log(\'hey\') // expect to see \"hey\" printed in t         


        

Answer 1

The problem is that I was using jest --forceExit. Jest's logging model saves all the logs and spits them out later. --forceExit causes the process to bail before it reaches the spit-out-logs point.

Answer 2

I found a work around, despite the fact that sadly neither TERM=dumb, nor verbose: false nor upgrading to version 24 worked (I'm on 24.9). Just spy on the console, and you can see the results. Set it up with this:

const consoleSpy = jest.spyOn(console, 'log')

And then view the calls after running your tests using:

consoleSpy.mock.calls[0][0]

Answer 3

Try adding --verbose to the Jest arguments.

This worked for me.

Answer 4

This seems to be an ongoing issue.

With Node 10.7.0 and Jest 23.4.1, adding verbose: false to the jest config (per this suggestion) worked for me.

Edit

Now that I've gone to Jest 23.6 I also need to pass TERM=dumb as an environment variable, per Tamlyn's answer.

Answer 5

Update: this issue should be fixed as of Jest 24.

Another partial solution to the current bug affecting tests in --watch mode is to pass TERM=dumb as an environment variable.

TERM=dumb jest --watch

This has a small price in that it no longer clears the console before each test run so you have to scroll to see the results.