In particular, I want to be able to switch to 'error' mode rather than
throw a real error() on test failures, because that's a little more
responsive and might be recoverable. (On some Android devices the font
is slightly different, and tests fail as a result.)
before:
stack traceback:
[string "text.lua"]:9: in function 'draw'
[string "edit.lua"]:200: in function 'draw'
[string "run.lua"]:140: in function 'draw'
[string "main.lua"]:162: in function <[string "main.lua"]:155>
[C]: in function 'xpcall'
[string "app.lua"]:38: in function <[string "app.lua"]:20>
[C]: in function 'xpcall'
[love "boot.lua"]:370: in function <[love "boot.lua"]:337>
after:
stack traceback:
text.lua:9: in function 'draw'
edit.lua:200: in function 'draw'
run.lua:140: in function 'draw'
main.lua:162: in function <[string "main.lua"]:155>
[C]: in function 'xpcall'
app.lua:38: in function <[string "app.lua"]:20>
[C]: in function 'xpcall'
[love "boot.lua"]:370: in function <[love "boot.lua"]:337>
It seems to have been introduced in commit 46889593da back in Jan, and I
was using it to summarize multiple failing tests. However, it's not used
in that scenario anymore (and anyway it seems wasteful to compute the
stack for each failing test and then throw it all away).
This is all quite hacky. Many of my tests are unfortunately brittle to
changes in text rendering. Fortunately there's only one test that
currently requires a hacky special case (and a second test I tweaked
slightly to be more robust).
I can't think of a better approach. It doesn't help to standardize the
font, because version changes still come with changes to text-shaping
algorithms even if the font itself is unchanged. I could base all my
assertions on the widths of individual characters, but that would make
the tests much less readable and not express intent as clearly. So here
we are, with hopefully just a few hacky special cases (there might be a
few more as LÖVE v12 advances towards publication, and in further
versions).
To do this I need some support for multiple versions. And I need an
'error' mode to go with existing 'run' and 'source' modes
(`Current_app`). Most errors will automatically transition to 'source'
editor mode, but some errors aren't really actionable in the editor. For
those we'll use 'error' mode.
The app doesn't yet work with LÖVE v12. There are some unit tests failing
because of differences in font rendering.