Cypress session validation failure results in a 'existingSession.setup is not a function' error

[Lasidar]

Current behavior

While using the new experimental feature sessions in cypress 8.2.0, adding a session validation routine does not seem to work correctly. Specifically, when a session exists, but the validation routine returns false, an error is thrown saying that the setup function does not exist.

Here is a sample block of code that can reproduce this issue:

When running this for the first time:

When re-running this test:

Desired behavior

Cypress should fail the validation, and re-run the setup function as specified in the docs. For some reason, the current code somehow loses the setup function when validation fails.

Test code to reproduce

  it('fails the session setup on the second run', () => {
    var validateFlag = false
    cy.session('test', () => {
      validateFlag = true
      cy.log('setup')
    },
    {
      validate() {
        cy.log('validate')
        if (validateFlag) {
          return true
        }
        else {
          return false
        }
      },
    })
  });

Cypress Version

8.2.0

Other

No response

[kuceb]

Thanks, the existingSession.setup error is definitely a bug. This might be an issue related to retries, if you turn off retries do you get the same error?

However the test should still fail, that is expected. In order to prevent an endless loop if your validate function always returns false, we fail the test if we have just initialized the session via the setup function.
https://docs.cypress.io/api/commands/session#The-command-log

Note that in cases where the validate function fails immediately after setup creates the session, the test will fail with an error.

We should improve the error message to explain this to the user

[Lasidar]

@bkucera disabling retries does not seem to make a difference.

I understand having a validation continuously fail will ultimately cause the test to fail. I am more concerned about the setup command not being found.

[alexniculae]

Hello @bkucera - same as @Lasidar, disabling retries did not change anything for me either.

Same concern here, not a problem that this is failing, it's normal in the end - but the recreation process for a new session is never initiated because of the existingSession.setup is not a function error.

[alvaromartmart]

I can confirm this is an issue. It basically renders the validate function useless 😅 until this is fixed.

[bahmutov]

Also hit this problem

[bahmutov]

Few stack screenshots, seems the setup suddenly becomes a fn.toString() output. Is this serialized somewhere?

[bahmutov]

Maybe in

cypress/packages/driver/src/cy/commands/sessions.ts

Lines 609 to 615 in 2caa5de

	.then(async () => {
	await navigateAboutBlank()
	const data = await sessions.getCurrentSessionData()
	Cypress.log({ groupEnd: true, emitOnly: true })
	_.extend(existingSession, data)

We might need to omit setup from serialized properties, otherwise when restored the string overwrites the original callback

[bahmutov]

Ohh, it was a little bit lower in

cypress/packages/driver/src/cy/commands/sessions.ts

Lines 807 to 810 in 2caa5de

	// we have a saved session on the server AND setup matches
	if (serverStoredSession && serverStoredSession.setup === existingSession.setup.toString()) {
	_.extend(existingSession, serverStoredSession)
	existingSession.hydrated = true

Patching it to be

if (serverStoredSession && serverStoredSession.setup === existingSession.setup.toString()) {

            lodash__WEBPACK_IMPORTED_MODULE_0___default.a.extend(existingSession,
              lodash__WEBPACK_IMPORTED_MODULE_0___default.a.omit(serverStoredSession, 'setup'));

fixed my problem

[alexniculae]

Hello @bkucera - is the change propose by Bahmutov, or another fix for this issue, planned to be introduce in an upcoming release?
Thank you,
Alex

[ComicScrip]

Had the same issue, any news on this ?

[eLarocque]

Same issue here. Providing the validate function is useless until this is fixed.
I know this is an experimental feature (and a great one at that!) but would love this issue prioritized :)
Thanks!

[DanaGoyette]

In my case, since I haven't generally had sessions become invalid in the middle of the run, I can work around it by clearing all sessions at the start of the run. In support/index.ts (might need syntax tweaking if using js):

before(() => {
  /**
   * Workaround for https://github.com/cypress-io/cypress/issues/17805
   * @see https://docs.cypress.io/api/commands/session#Explicitly-clearing-sessions
   */
  Cypress.session.clearAllSavedSessions()
})

[cypress-bot]

The code for this is done in cypress-io/cypress#21226, but has yet to be released.
We'll update this issue and reference the changelog when it's released.

[cypress-bot]

Released in 9.6.1.

This comment thread has been locked. If you are still experiencing this issue after upgrading to
Cypress v9.6.1, please open a new issue.