tree: 8b945c149172b3b62bc18bc3665a315d1e2db66f [path history] [tgz]
  1. app/
  2. .gitattributes
  3. .gitignore
  4. BUILD
  7. server.go
  8. wct.conf.js


Installing Node.js

The minimum nodejs version supported is 6.x+

# Debian experimental
sudo apt-get install nodejs-legacy

# OS X with Homebrew
brew install node

All other platforms: download from

Installing Bazel

Follow the instructions here to get and install Bazel.

Local UI, Production Data

This is a quick and easy way to test your local changes against real data. Unfortunately, you can't sign in, so testing certain features will require you to use the “test data” technique described below.

Installing go

This is required for running the script below.

# Debian/Ubuntu
sudo apt-get install golang

# OS X with Homebrew
brew install go

All other platforms: download from

Then add go to your path:


Running the server

To test the local UI against


Then visit http://localhost:8081

Local UI, Test Data

One-time setup:

  1. Build Gerrit
  2. Set up a local test site. Docs here and here.

When your project is set up and works using the classic UI, run a test server that serves PolyGerrit:

bazel build polygerrit &&
  $(bazel info output_base)/external/local_jdk/bin/java \
  -jar bazel-bin/polygerrit.war daemon --polygerrit-dev \
  -d ../gerrit_testsite --console-log --show-stack-trace

Running Tests

One-time setup:

# Debian/Ubuntu
sudo apt-get install npm

# OS X with Homebrew
brew install npm

# All platforms (including those above)
sudo npm install -g web-component-tester

Note: it may be necessary to add the options --unsafe-perm=true --allow-root to the npm install command to avoid file permission errors.

Run all web tests:


To allow the tests to run in Safari:

  • In the Advanced preferences tab, check “Show Develop menu in menu bar”.
  • In the Develop menu, enable the “Allow Remote Automation” option.

If you need to pass additional arguments to wct:

WCT_ARGS='-p --some-flag="foo bar"' ./polygerrit-ui/app/

For interactively working on a single test file, do the following:


Then visit http://localhost:8081/elements/foo/bar_test.html

To run Chrome tests in headless mode:

WCT_HEADLESS_MODE=1 ./polygerrit-ui/app/

Toolchain requirements for headless mode:

  • Chrome: 59+
  • web-component-tester: v6.5.0+

Style guide

We follow the Google JavaScript Style Guide with a few exceptions. When in doubt, remain consistent with the code around you.

In addition, we encourage the use of ESLint. It is available as a command line utility, as well as a plugin for most editors and IDEs. It, along with a few dependencies, can also be installed through NPM:

sudo npm install -g eslint eslint-config-google eslint-plugin-html

eslint-config-google is a port of the Google JS Style Guide to an ESLint config module, and eslint-plugin-html allows ESLint to lint scripts inside HTML. We have an .eslintrc.json config file in the polygerrit-ui/ directory configured to enforce the preferred style of the PolyGerrit project. After installing, you can use eslint on any new file you create. In addition, you can supply the --fix flag to apply some suggested fixes for simple style issues. If you modify JS inside of <script> tags, like for test suites, you may have to supply the --ext .html flag.

Some useful commands:

  • To run ESLint on the whole app, less some dependency code: eslint --ignore-pattern 'bower_components/' --ignore-pattern 'gr-linked-text' --ignore-pattern 'scripts/vendor' --ext .html,.js polygerrit-ui/app
  • To run ESLint on just the subdirectory you modified: eslint --ext .html,.js polygerrit-ui/app/$YOUR_DIR_HERE
  • To run the linter on all of your local changes: git diff --name-only master | xargs eslint --ext .html,.js

We also use the polylint tool to lint use of Polymer. To install polylint, execute the following command.

npm install -g polylint

To run polylint, execute the following command.

bazel test //polygerrit-ui/app:polylint_test

Template Type Safety

Polymer elements are not type checked against the element definition, making it trivial to break the display when refactoring or moving code. We now run additional tests to help ensure that template types are checked.

A few notes to ensure that these tests pass

  • Any functions with optional parameters will need closure annotations.
  • Any Polymer parameters that are nullable or can be multiple types (other than the one explicitly delared) will need type annotations.

A few dependencies are necessary to run these tests:

npm install -g typescript fried-twinkie

To run on all files, execute the following command:

bazel test //polygerrit-ui/app:all --test_tag_filters=template --test_output errors

To run on a specific top level directory (ex: change-list)

bazel test //polygerrit-ui/app:template_test_change-list --test_output errors

To run on a specific file (ex: gr-change-list-view), execute the following command:

bazel test //polygerrit-ui/app:template_test_<TOP_LEVEL_DIRECTORY> --test_arg=<VIEW_NAME> --test_output errors
bazel test //polygerrit-ui/app:template_test_change-list --test_arg=gr-change-list-view  --test_output errors