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Contributing to Cypress

Thanks for taking the time to contribute! 😄

Once you learn how to use Cypress, you can contribute in many ways:

  • Join the Cypress Gitter chat and answer questions. Teaching others how to use Cypress is a great way to learn more about how it works.
  • Blog about Cypress. We display blogs featuring Cypress on our Examples page. If you'd like your blog featured, contact us.
  • Write some documentation or improve our existing docs. Know another language? You can help us translate them. See our guide to contributing to our docs.
  • Give a talk about Cypress. Contact us ahead of time and we'll send you some swag. 👕

Want to dive deeper into how Cypress works? There are several ways you can help with the development of Cypress:

Table of Contents

CI status

Build status Description
CircleCI cypress-test-node-versions
CircleCI cypress-test-ci-environments
CircleCI cypress-test-module-api
CircleCI cypress-test-nested-projects
CircleCI cypress-on
CircleCI cypress-test-example-repos
CircleCI docsearch-scraper
Docker Build Status cypress-docker-images
Build status Windows CI

Code of Conduct

All contributors are expecting to abide by our Code of Conduct.

Opening Issues

The most important things to do are:

Finally, if you are up to date, supported, have collected information about the problem, and have the best reproduction instructions you can come up with, you are ready to open an issue.

Common Fixes

Before filing a bug, make sure you are up to date. Your issue may have already been fixed. Even if you do not see the issue described as resolved in a newer version, a newer version may help in the process of debugging your issue by giving more helpful error messages.

See our document on installing cypress

Getting more information

For some issues, there are places you can check for more information. This may help you resolve the issue yourself. Even if it does not, this information can help us figure out and resolve an issue.

  • For issues in the web browser, check the JavaScript console and your Network tab in your DevTools.
  • Click on any command in the Command Log where the failure occurred, this will log more information about the error to the JavaScript console.
  • Use Cypress debug or pause commands to step through your commands.
  • Ask other Cypress users for help in our chat.

Describe Problems

When you file a feature request, we need you to describe the problem you are facing first, not just your desired solution.

Often, your problem may have a lot in common with other similar problems. If we understand your use case, we can compare it to other use cases and sometimes find a more powerful or more general solution which solves several problems at once. Understanding the root issue can let us merge and contextualize things. Sometimes there's already a way to solve your problem that might just not be obvious.

Also, your proposed solution may not be compatible with the direction we want to take the product, but we may be able to come up with another solution which has approximately the same effect and does fit into the product direction.

Reproducibility

It is nearly impossible for us to resolve many issues if we can not reproduce them. Your best chance of getting a bug looked at quickly is to provide a repository with a reproducible bug that can be cloned and run.

Triaging Issues

When an issue is opened in cypress, we need to evaluate the issue to determine what steps should be taken next. So, when approaching new issues, there are some steps that should be taken.

1. Is this already an open issue?

Search all issues for keywords from the issue to ensure there isn't already an issue open for this. GitHub has some search tips that may help you better find the relevant issue.

2. Is what they are describing actually happening?

The best way to determine the validity of a bug is to recreate it yourself. Follow the directions or information provided to recreate the bug that is described. Did they provide a repository that demonstrates the bug? Great - fork it and run the project and steps required. If they did not provide a repository, the best way to reproduce the issue is to have a 'sandbox' project up and running locally for Cypress. This is just a simple project with Cypress installed where you can freely edit the application under test and the tests themselves to recreate the problem.

Attempting to recreate the bug will lead to a few scenarios:

1. You can not recreate the bug

Leave a comment on the issue saying, "I can't reproduce this situation with the code you provided. Could you provide more information or a repository demonstrating the bug?"

2. You can recreate the bug

Leave a comment on the issue saying "I was able to reproduce this in Cypress version x.x.x" If you know where the code is that could possibly fix this issue - link to the file or line of code from the cypress repo and remind the user that we are open source and that we gladly accept PRs, even if they are a work in progress.

3. You can tell the problem is a user error

In recreating the issue, you may realize that they had a typo or used the Cypress API incorrectly, etc. Leave a comment informing the user of their error and close the issue – or ask them to close the issue if it fixes their problem.

Writing Documentation

Cypress documentation lives in a separate repository with its own dependencies and build tools. See Documentation Contributing Guideline.

Writing code

Working on your first Pull Request? You can learn how from this free series How to Contribute to an Open Source Project on GitHub

What you need to know before getting started

Cypress and Packages

Cypress is a large open source project. When you want to contribute to Cypress, you may be unsure which part of the project to work within.

This repository is made up of various packages. They are discrete modules with different responsibilities, but each is necessary for the Cypress app and is not necessarily useful outside of the Cypress app.

Here is a list of the core packages in this repository with a short description, located within the packages directory:

Folder Name Purpose
cli The command-line tool that is packaged as an npm module.
coffee A centralized version of CoffeeScript used for other packages.
desktop-gui The front-end code for the Cypress Desktop GUI.
driver The code that is used to drive the behavior of the API commands.
electron The Cypress implementation of Electron.
example Our example kitchen-sink application.
extension The Cypress Chrome browser extension
https-proxy This does https proxy for handling http certs and traffic.
launcher Finds and launches browsers installed on your system.
reporter The reporter shows the running results of the tests (The Command Log UI).
root Dummy package pointing at the root of the repository.
runner The runner is the minimal "chrome" around the user's application under test.
server The <3 of Cypress. This orchestrates everything. The backend node process.
socket A wrapper around socket.io to provide common libraries.
static Serves static assets used in the Cypress GUI.
ts A centralized version of typescript.

We try to tag all issues with a pkg/ tag describing the appropriate package the work is required in. For example, the pkg/driver label is tagged on issues that require work in the driver package.

Requirements

You must have node and npm installed to run the project. We use avn, a utility to switch to the right npm version, in each folder. Currently, Cypress should be developed using the version specified in root .node-version file.

Getting Started

Install all dependencies:

npm install

This will install this repo's direct dependencies as well as the dependencies for every individual package.

Then, build all the packages and start the app:

npm run build
npm start

If there are errors building the packages, prefix the commands with DEBUG=cypress:* to see more details.

This outputs a lot of debugging lines. To focus on an individual module, run with DEBUG=cypress:launcher for instance.

When running npm start this routes through the CLI and eventually calls npm run dev with the proper arguments. This enables Cypress day-to-day development to match the logic of the built binary + CLI integration.

If you want to bypass the CLI entirely, you can use the npm run dev task and pass arguments directly.

Tasks

Each package is responsible for building itself and testing itself and can do so using whatever tools are appropriate, but each conforms to a standard set of npm scripts so that building, watching, testing, etc. can be orchestrated from the root of this repo. Here are the npm scripts supported and what they mean:

Task Purpose
build Build the package
build-prod Build all assets for production (if makes sense)
start Run a server for serving files
watch Watch source files and build development assets when they are saved. This may also run a server for serving files and run tests related to a saved file.
clean Remove any assets created by build-dev or build-prod
clean-deps Remove any dependencies installed (usually by npm)
test Runs all tests once
test-watch Run all tests in watch mode

Not every package requires or makes use of every script, so it is simply omitted from that package's package.json and not run.

You can run npm run all <script name> from the root directory to run a script in every package that utilizes that script. Many times, you may only be working on one or two packages at a time, so it won't be necessary or desirable to run a script for every package. You can use the --packages option to specify in which package(s) to run the script.

You can even run npm run all install to install all npm dependencies for each package. Note that this is already done automatically for you when you run npm install.

npm run all watch-dev -- --packages core-desktop-gui

Separate the package names with commas to specify multiple packages:

npm run all watch-dev -- --packages core-desktop-gui,core-runner

By default, all tasks run in parallel. This is faster than running serially, but the output ends up mixed together and, if things go wrong, it can be difficult see where the error occurred. To run tasks serially, use the --serial flag:

npm run all build-prod -- --serial

build-prod will be run sequentially for every package, so the output for each package won't be jumbled with the output of the others.

It is not recommended to use --serial with any script that is long-running, like watch-dev or test, since they need to be parallel.

Debugging

Some packages use debug to log debug messages to the console. The naming scheme should be cypress:<package name>. For example to see launcher messages during unit tests start it using

cd packages/launcher
DEBUG=cypress:launcher npm test

If you want to see log messages from all Cypress projects use wild card

DEBUG=cypress:*

Or for an individual package:

DEBUG=cypress:cli
DEBUG=cypress:server
DEBUG=cypress:launcher

Coding Style

We use eslint to lint all JavaScript code and follow rules specified in eslint-plugin-cypress-dev plugin.

Tests

For most packages there are typically unit and some integration tests.

Our true e2e tests are in packages/server, which test the full stack all together.

Please refer to each packages' README.md which documents how to run tests. It is not feasible to try to run all of the tests together. We run our entire test fleet across over a dozen containers in CI.

If you're curious how we manage all of these tests in CI check out our circle.yml file found in the root cypress directory.

Docker

Sometimes tests pass locally, but fail on CI. Our CI environment should be dockerized. In order to run the same image locally, there is script scripts/run-docker-local.sh that assumes that you have pulled the image cypress/internal:chrome61 (see circle.yml for the current image name).

The image will start and will map the root of the repository to /cypress inside the image. Now you can modify the files using your favorite environment and rerun tests inside the docker environment.

hint sometimes building inside the image has problems with node-sass library

Error: Missing binding /cypress/packages/desktop-gui/node_modules/node-sass/vendor/linux-x64-48/binding.node
Node Sass could not find a binding for your current environment: Linux 64-bit with Node.js 6.x

Found bindings for the following environments:
  - OS X 64-bit with Node.js 6.x

This usually happens because your environment has changed since running `npm install`.
Run `npm rebuild node-sass` to build the binding for your current environment.

From the running container, go into that project and rebuild node-sass

$ npm run docker
cd packages/desktop-gui
npm rebuild node-sass

Packages

Generally when making contributions, you are typically making them to a small number of packages. Most of your local development work will be inside a single package at a time.

Each package documents how to best work with it, so simply consult the README.md of each package.

They will outline development and test procedures. When in doubt just look at the scripts of each package.json file. Everything we do at Cypress is contained there.

Committing Code

Branches

The repository is setup with two main (protected) branches.

  • master is the code already published in the last Cypress version.
  • develop is the current latest "edge" code. This branch is set as the default branch, and all pull requests should be made against this branch.

Pull Requests

  • When opening a PR for a specific issue already open, please name the branch you are working on using convention issue-[issue number]. For example, if your PR fixes Issue #803, name your branch issue-803.
  • Please use the address #[issue number] or closes #[issue number] syntax in the pull request description.
  • Please check the "Allow edits from maintainers" checkbox when submitting your PR. This will make it easier for the maintainers to make minor adjustments, to help with tests or any other changes we may need. Allow edits from maintainers checkbox

Testing

This repository is exhaustively tested by CircleCI. Additionally we test the code by running it against various other example projects. See CI badges and links at the top of this document.

To run local tests, consult the README.md of each package.

Deployment

We will try to review and merge pull requests quickly. After merging we will try releasing a new version. If you want to know our build process or build your own Cypress binary, read DEPLOY.md