Cypress Utils

Easily parallelize and stress-test your Cypress tests

Cypress Utils is a command-line interface for parallelizing and stress-testing your Cypress tests.

To get started, just run npx cypress-utils --help.

Commands

Run tests in parallel

To speed up day-to-day local Cypress test runs (e.g. before committing changes to a branch), multiple Cypress test runners can be ran in parallel. The impact on system resources is surprisingly manageable, even with multiple concurrent runners.

In my unscientific n=1 sample size of running an entire suite, specifying two concurrent test runners provided the best results.

The total elapsed time was reduced by 38% when running a set of 12 tests in two concurrent threads

To run the entire suite in parallel, exclude any additional command-line arguments:

  cypress-utils run-parallel

Use the command-line option excludeSpecPattern to exclude specific files.

  cypress-utils run-parallel --excludeSpecPattern *.hot-update.js	

To run two or more specific test files in parallel, just specify the files to run:

  cypress-utils run-parallel specFileA.cy.js specfileB.cy.js

See more command-line options with cypress-utils run-parallel --help

Example of running tests in parallel:

Stress test

To ensure your Cypress tests are not irregularly failing with false-negatives, stress testing new test files can be a reliable way of filtering out bad test code.

To stress test one or more test files, simply specify the files to run:

  cypress-utils stress-test specFileA specfileB

Additional command-line options may be specified, such as the sample size or number of concurrent threads:

 cypress-utils stress-test --trialCount 12 --threads 4

See more command-line options with cypress-utils stress-test --help

Example of stress testing:

Installation

Install Cypress Utils to your project as a development dependency:

npm install --save-dev cypress-utils

Or run it once with the node package runner:

npx cypress-utils --help

Development Setup

1. Clone the repository:

git clone https://github.com/trentrand/cypress-utils.git

2. Install package dependencies:

cd /path/to/cypress-utils
npm install

3. Make cypress-utils globally executable:

npm link

Cypress Utils are now executable globally with the command cypress-utils.