`blockHosts` test configuration override failing to apply

Current behavior

Hello, I’ve been troubleshooting some strange behavior when leveraging the blockHosts configuration value and overriding the value with the Test Specific Configuration options.

Steps/setup:

1. blockHosts entry is added to the cypress.json configuration file as a string value (also tried an array with single string)
2. added an override for a test suite to set the blockHosts entry to null (the default) describe('my suite', {blockHosts: null}, () => {});

Current setup:

// cypress.json
{ "blockHosts": "*.pendo.io" }

// integration/my-suite.test.js
describe('my suite', {blockHosts: ''}, () => {});

The specific my suite test suite continues to block requests to pendo.io.

What I’ve identified thus far:

1. config is set properly (confirmed the settings GUI)
2. logged the Cypress.config() value and confirmed that blockHosts is mutated to be an empty string
3. The x-cypress-matched-blocked-host gets set with the original blockHosts value

I have tried with various different values for the blockHosts and also tried using the Cypress.config API directly but experienced the same behavior. From my understanding the blockHosts configuration value is not one of the read only configuration options.

Desired behavior

When providing blockHosts as a configuration value for a test suite, it should override the current blockHosts value and the cypress test should respect the new blockHosts value. This same override should be applicable using Cypress.config('blockHosts', '')

Test code to reproduce

https://github.com/cbourdage/cypress-test-tiny/pull/1

I have been able to replicate this in 2 repos now so you should be able to use any existing tests to try to override the blockHosts configuration option.

Cypress Version

9.3.1

Other

No response

[cupcakepanda89]

I’m on v10.4.0 and have similar issue, blockHosts seems not working correctly.

[jennifer-shehane]

blockHosts should override the config via a test config override. Looks like a bug. I’m not sure that we have tests for this internally (couldn’t find them quickly).