In order to extract the PNG files produced by our CanvasKit gms,
we need our JS tests to POST them to a server which can write to
disk. The easiest way to do this is to use the test_on_env
rule defined in the Skia Infra repo for exactly this purpose.
This required https://skia-review.googlesource.com/c/buildbot/+/510717
to be able to configure the binary correctly and
https://skia-review.googlesource.com/c/buildbot/+/511862, for nicer
debugging so the skia-infra dep was updated via the following commands:
$ go get go.skia.org/infra@d8a552a29e
$ go mod download
$ make -C infra/bots train
$ make -C bazel gazelle_update_repo
This caused many automated changes to infra/bots/tasks.json
The flow is:
1. User types bazelisk test :hello_world_test_with_env
2. The test_on_env rule starts gold_test_env and waits
for the file defined in $ENV_READY_FILE to be created.
3. gold_test_env starts a web server on a random port. It
writes this port number to $ENV_DIR/port. Then, it
creates $ENV_READY_FILE to signal ready.
4. test_on_env sees the ready file and then starts the
karma_test rule. (Reminder: this is a bash script
which starts karma using the Bazel-bundled chromium).
5. The karma_test rule runs the karma.bazel.js file (which
has been injected with some JS code to fill in Bazel
paths and settings) using Bazel-bundled node. This reads
in the port file and sets up a Karma proxy to redirect
/gold_rpc/report to http://localhost:PORT/report
6. The JS tests run via Karma (and do assertions via Jasmine).
Some tests, the gms, make POST requests to the proxy.
7. gold_test_env gets these POST requests writes the images
to a special Bazel folder on disk as defined by
$TEST_UNDECLARED_OUTPUTS_DIR.
8. test_on_env identifies that the tests finish (because the
karma_test script returns 0). It sends SIGINT to gold_test_env.
9. gold_test_env stops the webserver. The special Bazel folder
will zip up anything inside it and make it available for
future rules (e.g. a rule that will upload to Gold via goldctl).
Suggested Review Order:
- bazel/karma_test.bzl to see the test_on_env rule bundled into
the karma_test macro. I chose to put it there because it might
be confusing to have to define both a karma_test and test_on_env
rule in the same package but not be able to call one because it
will fail to talk to the server.
- gold_test_env.go to see how the appropriate files are written
to signal the environment is ready and the handlers are set up.
- karma.bazel.js to see how we make our own proxy given the
port from the env binary. The fact that we could not create
our own proxy with the existing karma_test rule was why the
chain ending in https://skia-review.googlesource.com/c/skia/+/508797
had to be abandoned.
- tests/*.js to see how the environment is probed via /healthz
and then used to make POST requests with data.
- Everything else.
Change-Id: I32a90def41796ca94cf187d640cfff8e262f85f6
BUG: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/510737
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
acab911351