Share value from `before:spec` to `spec` in order to use value in tests

[alexniculae]

Current behavior

Hello team,

Asked the below in a Q&A Discussion, but as there was no answer and I cannot find anything online, I'm trying here as well.

Q: Is it possible to share a value from the Before Spec API to the actual spec, so it can be used in the tests?

For example I tried to do it by leveraging the config object of Cypress and trying to create a new Cypress env var:

const {someFunc} = require('./some-func');

module.exports = (on, config) => {
  return on('before:spec', async () => {
    return someFunc().then((response) => {
      config.env.RESPONSE = response;
      return config;
    });
  });
}

Unfortunately I cannot get this to work, but I'm not sure if

• either I'm missing something, or
• if it's simply not doable like this because of how the config and the env of Cypress is built

Desired behavior

A solution for this or any other suggestions (that use the before:spec) would be great! 🙂

It'd also be great if there would be a way to also pass a value FROM the spec file TO the before:spec

Cypress Version

"cypress": "9.6.1"

[tbiethman]

@alexniculae sharing data between the before:spec event and the spec itself (or vice versa) is not possible today. Is there a reason why before:spec needs to be used in your case? Your example seems like it'd be perfect as a before hook in a spec helper, but I'm probably missing some context.

[alexniculae]

@tbiethman, glad that you asked about the use for this request.

As an example, let's say we have 100 spec files that we want to run in parallel on 5 machines/runners.

The only major issue we need to overcome in order to do this is have a semaphore system for our test users, in order to not generate conflicts in these parallel runs.

In our example, let's say we have 10 users that are available for us to use in the specs

• unfortunately, due to business reasons, we cannot have more then these 10 users
• one options that could be considered then would be to assign 2 test users to each CI machine/runner and no more conflicts
  • unfortunately this would not be a valid option , as some tests require the use of 3 users for example, or maybe even more of them

I have tried to find some examples or any documentation about this being done with Cypress but could not find any.

The logic I thought of:

• use Consul for the semaphore system (lock users via sessions)
• use the before:spec event to request a free user, in order to do the (if necessary) waiting in the backend, before opening the browser

The limitations I am hitting against:

• it's complicated to tell the before:spec which spec needs how many users
  • I tried to do that with a simple const {requiredNoOfUsers} = require(spec.absolute), but the Cypress runner will fail
  • this is due to Error: describe is not defined or Error: Cypress is not defined
  • to work around this I'll need to build a separate JSON file with key-value = specName-noOfUsers and pass this to the before:spec
• it's then complex to return the locked users to back to the spec, in order to use them
  • the way I am trying to achieve this today is by adding the spec.name as a value to the key in Consul and, from the spec making an http call to Consul and filtering on the key that has the value===Cypress.spec.name

Any input would be appreciated

• is there a better way to solve this then Consul semaphore, by following Cypress best practices and considering our limitations?
• is there a simpler solution I can use with the Consul semaphore? maybe I am overcomplicating things without realizing it

Thank you