Warning: .then() only accepts functions but was passed: [object Undefined] when running Cypress in Docker

[blomqma]

Current behavior

So when running Cypress inside a Docker container with node:15.10.0-buster-slim image and all the required runtime dependencies from cypress/base Docker image, the terminal will be full of the following output on literally every test case.

Desired behavior

Obviously, no such output should exist.

Test code to reproduce

I doubt this has nothing to do with the syntax of my test cases themselves, the error reproduces on every test with even empty contents so anything can be used - I think it's related to the node version somehow.

Versions

Cypress: 6.5.0
Docker image: node:15.10.0-buster-slim

[jennifer-shehane]

Can you provide a reproducible example? This is likely dependent on the project you are running - can you provide a repo? Here are some tips for providing a Short, Self Contained, Correct, Example and our own Troubleshooting Cypress guide.

[jennifer-shehane]

I couldn't recreate this running Node 15.10.0 with a sample project.

[pmerwin]

I see this output in our github actions running on Ubuntu: latest: with node 12

    (node:2795) Warning: .then() only accepts functions but was passed: [object Undefined]
(node:2795) Warning: .then() only accepts functions but was passed: [object Undefined]

(node:2262) Warning: a promise was created in a handler at internal/timers.js:456:21 but was not returned from it, see http://goo.gl/rRqMUw
    at Function.Promise.cast (/home/runner/.cache/Cypress/6.6.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:225:13)

[pmerwin]

@jennifer-shehane I believe to reproduce you can create a github workflow with cypress-io/github-action@v2

[kkaarreell]

I am seeing similar problem on RHEL container. The issue appeared after a cypress update. The traceback looks as follows

(node:8997) Warning: .then() only accepts functions but was passed: [object Undefined]
    at Object.wrapChildPromise (/home/travis/.cache/Cypress/6.6.0/Cypress/resources/app/packages/server/lib/plugins/util.js:42:8)
    at Object.wrap (/home/travis/.cache/Cypress/6.6.0/Cypress/resources/app/packages/server/lib/plugins/child/task.js:53:8)
    at execute (/home/travis/.cache/Cypress/6.6.0/Cypress/resources/app/packages/server/lib/plugins/child/run_plugins.js:127:19)
    at EventEmitter.<anonymous> (/home/travis/.cache/Cypress/6.6.0/Cypress/resources/app/packages/server/lib/plugins/child/run_plugins.js:202:5)
    at EventEmitter.emit (events.js:315:20)
    at process.<anonymous> (/home/travis/.cache/Cypress/6.6.0/Cypress/resources/app/packages/server/lib/plugins/util.js:19:22)
    at process.emit (events.js:315:20)
    at emit (internal/child_process.js:903:12)
    at processTicksAndRejections (internal/process/task_queues.js:81:21)

[kkaarreell]

Not an expert but to me it seems that wrapChildPromise is not getting the cb parameter.

  wrapChildPromise (ipc, invoke, ids, args = [], cb) {
    return Promise.try(() => {
      return invoke(ids.eventId, args)
    }).then(cb)

$ pwd
/home/testuser/.cache/Cypress/6.6.0/Cypress/resources/app/packages/server
$ grep -R wrapChildPromise
lib/plugins/util.js:  wrapChildPromise (ipc, invoke, ids, args = [], cb) {
lib/plugins/child/browser_launch.js:    util.wrapChildPromise(ipc, invoke, ids, args)
lib/plugins/child/dev-server.js:  util.wrapChildPromise(ipc, invoke, ids, [options])
lib/plugins/child/preprocessor.js:  util.wrapChildPromise(ipc, invoke, ids, [childFile])
lib/plugins/child/run_plugins.js:  const wrapChildPromise = () => {
lib/plugins/child/run_plugins.js:    util.wrapChildPromise(ipc, invoke, ids, args)
lib/plugins/child/run_plugins.js:      return wrapChildPromise()
lib/plugins/child/task.js:  util.wrapChildPromise(ipc, invoke, ids)
lib/plugins/child/task.js:  util.wrapChildPromise(ipc, invoke, ids)
lib/plugins/child/task.js:  util.wrapChildPromise(ipc, invoke, ids, [arg])

[jweingarten]

Same problem here ... since 6.5.0 upgrade.

[kkaarreell]

Hi @jennifer-shehane , may I ask for a review? I believe the root cause is clear now and the fix should be also simple (e.g. define a default callback function for the cb parameter or just check it is not undefined before calling it).

[joelgrimberg]

same issue here, without running in Docker.. I will try to setup an example-repo

[jahusa02]

I have exactly the same problem with the cypress/base:10 image. Also my tests wont fail.

[jennifer-shehane]

@kkaarreell Yah, this likely has something to do with it. I'm not sure why this warning only displays for some people and not others. Do any of you have nodeVersion set in Cypress?