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  1. 75821fa chumpdetector: migrate to new tree status service by Matthew Warton · 4 weeks ago main
  2. ac74f71 Support using chumpdetector without tree status by Gavin Mak · 8 weeks ago
  3. 3fb8741 README: clarify project name usage by Mike Frysinger · 9 months ago
  4. 3db4070 Clarify inheritance section by Gavin Mak · 1 year, 1 month ago
  5. a9a0d6c Add info on how inheritance and how to disabled for child repos. by Joanna Wang · 1 year, 4 months ago

ChumpDetector Plugin for Gerrit

This plugin will allow developers to see the current status on their CLs. Status will be pulled from a configurable location. The Chromium project has many status sites such as:

The plugin will show users the status and will warn them in certain situations if they attempt to undertake actions that are contrary to the tree status.

The plugin does not provide enforcement - that is provided by other systems.


Before this plugin will work you'll need to configure it. You can do that by adding a new file to refs/meta/config for a Gerrit project. The configuration file should be called chumpdetector.config and should be of the form:

[project "some-interesting-project"]
    treeId = chromium
    enforceCommitQueue = false
    disabledBranchPattern = ^(refs/meta/config|.*)$

Project name

The project name doesn‘t matter, it can be anything you’d like. It will be displayed to the user in messages to refer to the project itself.


The name of the tree to display status of. This should be the same as the last component of the URL to view your tree, e.g. for the treeId is chromium.


When true, this will show a modal warning to users if they try to submit the CL directly and warn them to use the CQ. This is Chromium concept, unless you have a Chromium-like CQ system. Just leave as false if you don't understand what any of those things mean.


Anyone defining this property is strongly recommended to include refs/meta/config since we never enable the CQ on this branch.

CLs on branches that match this pattern will have the plugin disabled. This means they won‘t see tree status and tree status won’t effect the CL in any way.

The branch name comes from the Gerrit CL ChangeInfo. The refs/heads/ prefix is omitted, but otherwise is the full name. Common examples are main (in the case of refs/heads/main) and refs/meta/config.

The pattern syntax uses JavaScript Regular expressions with no flags. This means the match is case-sensitive, and you should use ^ and $ anchors to avoid accidental partial matches. For example, the pattern main will match any branch name that has the substring main in it, not only the main branch itself.

There is no need to quote the string. If quotes are used, they are automatically stripped (outermost only). For example, "^main$" is turned into ^main$.


This setting causes the plugin to request a URL via an an image that is dynamically added to the page before making any other fetch requests. This is useful in situations where the request to the status URL will fail without certain cookies being set for the status request domain. By using an image tag the browser will correctly follow any redirects that a login process may require in order to establish the session cookies.

Most installs will not need this configuration and can ignore it. For certain sites this may allow them to get security cookies before attempting status requests which will fail without the cookies.

Deprecated: loginURL

This field is deprecated and no longer used.

If withCredentials is true and a request for status fails, the system assumes that a login is required and has not occurred. In that case the status message will change to “Login required. Click here to login.” The text will be a link that points to the value of loginURL. If loginURL is not set then the message will just be RequestError: Login required. with no link.

Deprecated: viewURL

This field is deprecated and no longer used.

This should be the URL to your status app. This is used to provide a link that users can click on to take them to a new page that shows the full status.

Deprecated: statusURL

This field is deprecated. It is only used during migration to obtain a treeName value if one is not specified directly in the configuration.

This should be the URL to get a JSON blob of the current status. Usually this will be related to the viewURL value. This is the URL that will be queried via XHR periodically while the user is on the page to update the tree status.

Deprecated: withCredentials

This field is deprecated and no longer used.

This is simply passed through to the underlying JavaScript XMLHttpRequest object as the withCredentials parameter. You can read about it at


Repos with no chumpdetector.config will inherit it from the inheritFrom repo in project.config. To disable the plugin for a repo, without breaking the inheritance, create a chumpdetector.config for the repo with:

[project "some-interesting-project"]
    disabled = true

Make sure the project name matches the one in the parent repo's chumpdetector.config, otherwise the plugin will not be disabled.

Web Plugin Development

Run the commands below in web/.

For running TypeScript unit tests execute:

make test

For checking or fixing eslint formatter problems run:

make lint_test
make lint_fix

For testing the plugin with Gerrit FE Dev Helper the command below builds the JavaScript bundle and copies it to the plugins/chumpdetector folder:

make build

Start polygerit-ui server:

./polygerrit-ui/ --plugins="plugins"

and let the Dev Helper redirect from .+/plugins/chumpdetector/static/chumpdetector.js to http://localhost:8081/plugins/chumpdetector.js.