Jest: example async test or resolve will not work and return error of ` TypeError: Cannot read property 'then' of undefined`

[achenwei-chwy]

Do you want to request a _feature_ or report a _bug_?
Bug

What is the current behavior?
Return error when setup the test and mock properly 99% according to the tutorial page here https://facebook.github.io/jest/docs/en/asynchronous.html

**If the current behavior is a bug, please provide the steps to reproduce and
either a repl.it demo through https://repl.it/languages/jest or a minimal
Test suppose to pass. An exampl here
https://github.com/adamchenwei/jest-playground
run npm install && npm run test:watch you should observe the error.

What is the expected behavior?
Test should pass as tutorial indicated.

Please provide your exact Jest configuration and mention your Jest, node,
yarn/npm version and operating system.
They are in the demo repo https://github.com/adamchenwei/jest-playground

[achenwei-chwy]

Not really sure what is the significant difference beside I config the jest to place test in the same folder as component as well as use timeout instead of process.nextTick

[jack-evans]

In the doc folder where you define user.js and request.js you should have a __mocks__ folder and within that you should define the request.js mock function.

[achenwei-chwy]

@jack-evans how you know that so quickly? Did I missed it from the doc reading? Or there is way somehow you debug and found the issue? ? Super curious to know how you did that!!!
Just in case anyone interested in the fix.. https://github.com/adamchenwei/jest-playground/commit/08a861ff15daac7d5ee5aaa7b0e71bd3369abc85

[jack-evans]

There is this on the Jest website that I remember using when i first wrote some manual mocks:

https://facebook.github.io/jest/docs/en/manual-mocks.html

so only if you're mocking a node module do you put it at the root level (or the level at which your node modules folder is located)

In terms of the debugging:
Cannot read property 'then' of undefined means that in the case of something.then(...), the something is undefined, the only thing in user that did .then was after the request so I knew there was an issue with making the request....

In addition there was this console.log line which wasnt being printed so I knew that request wasnt being mocked properly