it.only gives "Cannot read properties of undefined (reading 'parent')" with Stack Overflow solution for soft assertion

[MikeMcC399]

Stack Overflow: "Does cypress support soft assertion?" which was published over 3 years ago suggests a solution for soft assertion.

At the time the contribution was published, it.only originally worked with Cypress 3.8.3 and excluded other tests from running. Since that time, attempting to use it.only causes an error (Cannot read properties of undefined (reading 'parent')) using the Stack Overflow code starting with Cypress 4.0.0 and including the latest Cypress 10.11.0.

I asked in July 2022 in the above Stack Overflow article if there is a solution to allow it.only to work with this suggested code. There hasn't been any solution there yet.

Can anybody advise what needs to be changed to get it.only to work in this environment?

The Stack Overflow post: How can I make .only and this to work after hacking the Cypress hook? also didn't receive any solution for it.only so far.

Steps to reproduce

To reproduce, take the code from Stack Overflow: "Does cypress support soft assertion?" and add it into support/index.js (Cypress 9 and earlier) or into support/e2e.js (Cypress 10), then execute the simple Cypress test spec:

describe('it.only test', () => {
    it.only('test', () => {
        cy.log("Printing a message to the Cypress Command Log.")
    });
});

The console logs shows the following on Cypress 9.7.0:

TypeError: The following error originated from your test code, not from Cypress.

  > Cannot read properties of undefined (reading 'parent')

When Cypress detects uncaught errors originating from your test code it will automatically fail the current test.

Cypress could not associate this error to any specific test.

We dynamically generated a new test to display this failure.
    at Object.only (http://localhost:63799/__cypress/runner/cypress_runner.js:125030:14)
    at Function.context.it.only (http://localhost:63799/__cypress/runner/cypress_runner.js:124834:26)
    at Function.only (http://localhost:63799/__cypress/runner/cypress_runner.js:183242:21)
    at Object.create (http://localhost:63799/__cypress/runner/cypress_runner.js:125002:19)
    at context.describe.context.context (http://localhost:63799/__cypress/runner/cypress_runner.js:124778:27)
    at http://localhost:63799/__cypress/runner/cypress_runner.js:183242:21
    at http://localhost:63799/__cypress/runner/cypress_runner.js:186274:16
    at arrayEach (http://localhost:63799/__cypress/runner/cypress_runner.js:41318:11)
    at Function.forEach (http://localhost:63799/__cypress/runner/cypress_runner.js:50198:14)
    at evalScripts (http://localhost:63799/__cypress/runner/cypress_runner.js:186273:49)
    at http://localhost:63799/__cypress/runner/cypress_runner.js:186281:152
From previous event:
    at runScriptsFromUrls (http://localhost:63799/__cypress/runner/cypress_runner.js:186281:136)
    at Object.runScripts (http://localhost:63799/__cypress/runner/cypress_runner.js:186296:12)
    at $Cypress.onSpecWindow (http://localhost:63799/__cypress/runner/cypress_runner.js:174692:76)

or after migrating to Cypress 10.4.0, where the error message is identical to 9.7.0 and the stack trace is also the same, apart from line numbers:

TypeError: The following error originated from your test code, not from Cypress.

  > Cannot read properties of undefined (reading 'parent')

When Cypress detects uncaught errors originating from your test code it will automatically fail the current test.

Cypress could not associate this error to any specific test.

We dynamically generated a new test to display this failure.
    at Object.only (http://localhost:62671/__cypress/runner/cypress_runner.js:118180:14)
    at context.it.only (http://localhost:62671/__cypress/runner/cypress_runner.js:117984:26)
    at Function.only (http://localhost:62671/__cypress/runner/cypress_runner.js:176870:21)
    at Object.create (http://localhost:62671/__cypress/runner/cypress_runner.js:118152:19)
    at context.describe.context.context (http://localhost:62671/__cypress/runner/cypress_runner.js:117928:27)
    at http://localhost:62671/__cypress/runner/cypress_runner.js:176870:21
    at http://localhost:62671/__cypress/runner/cypress_runner.js:179915:16
    at arrayEach (http://localhost:62671/__cypress/runner/cypress_runner.js:40671:11)
    at Function.forEach (http://localhost:62671/__cypress/runner/cypress_runner.js:49551:14)
    at evalScripts (http://localhost:62671/__cypress/runner/cypress_runner.js:179914:49)
    at http://localhost:62671/__cypress/runner/cypress_runner.js:179922:152
From previous event:
    at runScriptsFromUrls (http://localhost:62671/__cypress/runner/cypress_runner.js:179922:136)
    at Object.runScripts (http://localhost:62671/__cypress/runner/cypress_runner.js:179937:12)
    at $Cypress.onSpecWindow (http://localhost:62671/__cypress/runner/cypress_runner.js:168145:76)

Expectation

Attempting to run the test spec above should run the test without any error message when using the code from Stack Overflow: "Does cypress support soft assertion?".

Under the old Cypress 3.8.3 version this is no problem:

[chip-ext-star]

hi @MikeMcC399.

I found a workaround:

window.it.only = (title, func) => {
  let cases = Cypress.env('CypressOnly');
  cases += ';';
  cases += title;
  Cypress.env('CypressOnly', cases);
  origIt(title, func && (() => itCallback(title, func)));
};

const filterTestCases = () => {
  const testFilter = Cypress.env('CypressOnly')?.split(';');
  let tests = Cypress.mocha.getRunner().suite.suites?.[0].tests;
  tests.forEach((test, index) => {
    if (testFilter?.length > 1 && !testFilter?.some(t => t.includes(test.title)))
      Cypress.mocha.getRunner().suite.suites[0].tests[index].pending = true;
  });
};

before(() => {
    filterTestCases();
})

Hope this helps you.

[MikeMcC399]

@thiagocosenza

how did you implement the solution of [(https://stackoverflow.com/questions/55868107/does-cypress-support-soft-assertion)] using Cypress >10.0? I didnt manage to do it, because index.js has gone.

I installed on Cypress 9 and then used the migration tool for Cypress 10. This renames support/index.js to support/e2e.js. See https://docs.cypress.io/guides/references/migration-guide#supportFile.

[thiagocosenza]

Good! Thank you. And did you manage to fix the it.only afterwards?

[MikeMcC399]

And did you manage to fix the it.only afterwards?

No. This issue is still unresolved.

[DPelyp]

hi @chip-ext-star

I found a workaround:

window.it.only = (title, func) => {
  let cases = Cypress.env('CypressOnly');
  cases += ';';
  cases += title;
  Cypress.env('CypressOnly', cases);
  filterTestCases();
  origIt(title, func && (() => itCallback(title, func)));
};

const filterTestCases = () => {
  const cypressOnly = Cypress.env('CypressOnly')?.split(';');
  if (!cypressOnly) return;
  let tests = Cypress.mocha.getRunner().suite.suites?.[0].tests;
  tests.forEach((test, index) => {
    if (cypressOnly.indexOf(test.title) < 0)
      Cypress.mocha.getRunner().suite.suites[0].tests[index].pending = true;
  });
};

Hope this helps you.

Didn't get how to fix the cy.only issue, test title should be added into env variable? Maybe you have example how to work with that? I will be very grateful

[MikeMcC399]

Hi again @chip-ext-star !

It looks like
origIt(title, func && (() => itCallback(title, func))); should be
origIt(title, func && (() => itCallback(func))); which allows it.only to work.

If you would like to check the above and modify your suggested code then I would set the discussion to "answered".

[MikeMcC399]

• I wonder if Gleb @bahmutov might weigh in on this issue? He commented on the same code in "this" context doesn't work as expected in one of my repos #17300 (comment)

• The original problematic code for support/e2e.js is on Stack Overflow: "Does cypress support soft assertion?" which causes a problem with it.only.

• it.only with this monkey patch stopped working with the Cypress 4.0.0 release which was the first release to allow multiple tests using it.only. In Cypress v3 it still worked.

In addition there is a new issue:

• it.skip stopped working in conjunction with the monkey-patch after updating Cypress 10.10.0 to Cypress 10.11.0
  it now produces the error message: "Cannot set properties of undefined (setting 'body')" logged under it.skip fails with soft assertions monkey-patch #24525 (support was declined for this issue and the issue is closed unresolved).

[chip-ext-star]

hi,

I make an example here: https://github.com/lehoanglu0ng/cypress-only

[MikeMcC399]

Hi @chip-ext-star

Thanks for your repo with the fix for it.only. I confirm that your test file works.

It would be great if it also worked with a test containing it.skip, although that wasn't part of the original discussion.
If I run a test with it.skip and with your modified monkey-patch I get the error:

TypeError: Cannot read properties of undefined (reading 'tests')

Because this error occurred during a `before all` hook we are skipping all of the remaining tests.
    at filterTestCases (webpack:///./cypress/support/e2e.js:105:58)
    at Context.eval (webpack:///./cypress/support/e2e.js:100:2)

[chip-ext-star]

Happy to hear it helps you. I will find the way to make it.skip works.