Renderers like delta and difftastic pick their colors for either a dark
or a light background, and they can't find out which one the terminal
has. Lazygit runs them with TERM=dumb, in a pty that doesn't answer
their queries. So the colors come from the config, and when the
terminal switches between dark and light, the diff keeps the ones it
has.
Add {{colorScheme}} to the commands of diff renderers. It is 'dark' or
'light', going by gui.colorScheme, or by the terminal if that is
'auto'. It can be passed to delta as --{{colorScheme}} and to
difftastic as --background={{colorScheme}}; other renderers can choose
between options with a template expression. When the terminal switches
between dark and light, render the diff again.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The command of a diff renderer can refer to values like the width it
renders at, as {{width}}. They are filled in by plain replacement, so a
command can't choose between options depending on them. The next commit
adds a value that needs this: whether the terminal is dark or light.
delta takes --dark or --light, but for other renderers the choice has to
be spelled out differently, for example as the name of a syntax theme.
Resolve the command as a Go template instead. The values become its
variables, so that {{if gt .width 160}} --side-by-side{{end}} works too.
To keep the existing commands working, a variable can still be written
without the leading dot.
A mistake in a template, such as a misspelled variable, now makes
resolving the command fail, instead of leaving the placeholder in it.
Check the commands when the config is loaded, by resolving each of them
with made-up values, so that the mistake shows up as an invalid config.
This also rejects a variable that the kind of renderer doesn't have,
such as {{columnWidth}} in the command of an external diff; until now,
it reached the renderer as it was.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Stefan HallerandClaude Opus 5.5