Skia Automated Testing


Skia uses Swarming to do the heavy lifting for our automated testing. It farms out tasks, which may consist of compiling code, running tests, or any number of other things, to our bots, which are virtual or real machines living in our local lab, Chrome Infra’s lab, or in GCE.

The Skia Task Scheduler determines what tasks should run on what bots at what time. See the link for a detailed explanation of how relative task priorities are derived. A task corresponds to a single Swarming task. A job is composed of a directed acyclic graph of one or more tasks. The job is complete when all of its component tasks have succeeded or is considered a failure when any of its component tasks fails. The scheduler may automatically retry tasks within its set limits. Jobs are not retried. Multiple jobs may share the same task, for example, tests on two different Android devices which use the same compiled code.

Each Skia repository has an infra/bots/tasks.json file which defines the jobs and tasks for the repo. Most jobs will run at every commit, but it is possible to specify nightly and weekly jobs as well. For convenience, most repos also have a gen_tasks.go which will generate tasks.json. You will need to install Go. From the repository root:

$ go get -u
$ go run infra/bots/gen_tasks.go

It is necessary to run gen_tasks.go every time it is changed or every time an asset has changed. There is also a test mode which simply verifies that the tasks.json file is up to date:

$ go run infra/bots/gen_tasks.go --test

Try Jobs

It is useful to know how your change will perform before it is submitted. After uploading your CL to Gerrit, you may trigger a try job for any job listed in tasks.json:

$ git cl try -B <bucket name> -b <job name>

The bucket name refers to the Buildbucket bucket to which the request will be submitted. Most public Skia repos use the “skia.primary” bucket, and most private Skia repos use the “skia.internal” bucket.

Status View

The status view shows a table with tasks, grouped by test type and platform, on the X-axis and commits on the Y-axis. The cells are colored according to the status of the task for each commit:

  • green: success
  • orange: failure
  • purple: exception (infrastructure issue)
  • black border, no fill: task in progress
  • blank: no task has started yet for a given revision

Commits are listed by author, and the branch on which the commit was made is shown on the very left. A purple result will override an orange result.

For more detail, you can click on an individual cell to get a summary of the task. You can also click one of the white bars at the top of each column to see a summary of recent tasks with the same name.

The status page has several filters which can be used to show only a subset of task specs:

  • Interesting: Task specs which have both successes and failures within the visible commit window.
  • Failures: Task specs which have failures within the visible commit window.
  • Comments: Task specs which have comments.
  • Failing w/o comment: task specs which have failures within the visible commit window but have no comments.
  • All: Display all tasks.
  • Search: Enter a search string. Substrings and regular expressions may be used, per the Javascript String Match() rules: