Cypress Grep - Faster Test Execution

By default, for the Cypress grep plugin when using the grep and grepTags all of the specs are executed and then each the filters are applied. This can be very wasteful, if only a few specs contain the grep in the test titles. Thus when doing the positive grep, you can pre-filter specs using the grepFilterSpecs=true parameter.

Examples

Example 1: To filter all specs first and then only run the suite or tests that match the title “it loads”

npx cypress run --env grep="it loads",grepFilterSpecs=true

Example 2: To filter all spec files and only run the specs with the tag “@smoke”

npx cypress run --env grepTags=@smoke,grepFilterSpecs=true

Notes

Note 1: this requires installing this plugin in your project’s plugin file like we did in our first Cypress Grep Plugin post.

Note 2: the grepFilterSpecs option is only compatible with the positive grep and grepTags options, not with the negative “!…” filter.

Note 3 if there are no files remaining after filtering, the plugin prints a warning and leaves all files unchanged to avoid the test runner erroring with “No specs found”.

Tip

You can set this environment variable in the cypress.json file to enable it by default and skip using the environment variable:

{
  "env": {
    "grepFilterSpecs": true
  }
}

By implement the grepFilterSpecs, you will get much better performance from Cypress grep as your tests suite grows in size.