This commit implements the following improvements for the test:
- Replace the hardcoded highlight padding with a dynamic calculation. It
turns out that the amount of padding can differ per system, possibly
due to e.g. local (font) settings, which could cause the test to fail.
The test now no longer implicitly depends on the environment.
- Remove the page offset subtraction. It's only needed for one assertion,
and we can simply add the page offset there once.
- Improve the "magic" numbers in the test. The number 5 is removed now
that the padding calculation made it obsolete, the number 28 is changed
to 30 because that's the actual value in the PDF data and the number 4
is explained a bit more to state that the space also counts as a glyph.
- Annotate the steps and checks to improve readability of the test and
to explain why certain calculations have to be performed.
253a7333d8