Note that these cases, which are all in older code, were found using the [`unicorn/no-for-loop`](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/no-for-loop.md) ESLint plugin rule.
However, note that I've opted not to enable this rule by default since there's still *some* cases where I do think that it makes sense to allow "regular" for-loops.
- Scroll the selected reference into view (makes it easier to tell which pdf you're looking at)
- Show the keyboard shortcuts (easier for new people)
- Keep the test/ref controls visible (if you scroll you can now tell if you're looking at a test or ref)
This will default to generating test images at the device pixel
ratio of the machine the tests are created on unless the
test explicitly defines and output scale using the
`outputScale` setting. This makes the test look visually
like they would on the machine they are running on. It
also allows us to test different output scales.
It shouldn't be necessary to assign these variables to the global scope (as far as I can tell), either explicitly with `window` or implicitly with `var`, and this way we don't need to disable the ESLint `no-undef` rule; fixes another small part of issue 13862.
*Please note:* I wasn't going to put additional work into this code after PR 13869, however these changes looked so simple that I figured trying to get rid of the few remaining "Code scanning alerts" wouldn't hurt.
However, this file would still very much benefit from additional clean-up and re-factoring work, since it's quite old and currently contains some dead code (commented out).
Given that issue 13862 tracks updating/modernizing the code, this patch purposely limits the scope of the changes. In particular, the following things are still left to address:
- The ESLint `no-undef` errors; for now the rule is simply disabled globally in this file.
- A couple of unused variables are commented out for now, but could perhaps just be removed.
This commit replaces our own infrastructure for handling browsers during
tests with Puppeteer. Using our own infrastructure for this had a few
downsides:
- It has proven to not always be reliable, especially when closing the
browser, causing failures on the bots because browsers were still
running even though they should have been stopped. Puppeteer should do
a better job with this because it uses the browser's test built-in
instrumentation tools for this (the devtools protocol) which our code
didn't. This also means that we don't have to pass
parameters/preferences to tweak browser behavior anymore.
- It requires the browsers under test to be installed on the system,
whereas Puppeteer downloads the browsers before the test. This means
that setup is much easier (no more manual installations and browser
manifest files) as well as testing with different browser versions
(since they can be provisioned on demand). Moreover, this ensures that
contributors always run the tests in both Firefox and Chrome,
regardless of which browsers they have installed locally.
- It's all code we have to maintain, so Puppeteer abstracts away how the
browsers start/stop for us so we don't have to keep that code.
By default, Puppeteer only installs one browser during installation,
hence the need for a post-install script to install the second browser.
This requires `cross-env` to make passing the environment variable work
on both Linux and Windows.
When reftest analyzer shows magnified pixels, there is a seemingly random offset between the mouse position and the magnified position. The reason for this is that reftest analyzer assumes all images have 800 * 1000 pixels but actually the test images have varying sizes.
The test runner is automated, so if the default browser test is
performed, the browser hangs waiting for user input it never gets.
Disable the test to fix that.
Moreover, enable E10s now that it is mature. This may help with the
performance of the test runner as well.
It's currently possible to step through the test results using the <kbd>N</kbd> and <kbd>P</kbd> keys, and you can also switch between test and reference images with the <kbd>T</kbd> key.
However if you want to highlight the differences, that can only be done by clicking. This has always annoyed me somewhat, so this patch adds support for toggling the differences view with the <kbd>D</kbd> key.
