All interaction tests are now lazily instrumented with Istanbul
to obtain code coverage. The interactions tests can be started
with `COVERAGE=1` to obtain coverage. For that, the Mocha hooks
perform the eventual reporting and gathering of data. The instrumentation
is performed in the components server itself.
To make sure that we perform the minimal amount of work required
(since code coverage instrumentation is computationally expensive),
we preload pages to populate the instrumentation cache. Every
interactions tests should preload an example (most likely basic.html)
to populate the cache. Every subsequent test will then use the
already-instrumented code, rather than computing the code over
and over again.
The eventual code coverage is written to /interactions-coverage.
The results will eventually be merged with /karma-coverage
to obtain the union of both unit and interaction tests coverage.
R=aerotwist@chromium.org,jacktfranklin@chromium.org
Bug: 1206705
Change-Id: I5e19b1ecef23d21107210699cb29800556e0415e
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2879986
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
Reviewed-by: Jack Franklin <jacktfranklin@chromium.org>
Kriti Sapra