til/git/highlight-extra-whitespace-in-diff-output.md

Highlight Extra Whitespace In Diff Output

When running a git diff (or git add --patch) I'll sometimes come across lines that don't have any visible changes. This is usually because some whitespace characters were either added (on accident) or removed (often by a autoformatter).

Depending on the core.whitespace config, you'll probably see at least some of the whitespace errors that git provides. By default, git only highlights whitespace errors on added (new) lines. However if some extra whitespace was originally committed and is now being removed, it won't be highlighted on the old line in the diff.

We can have git always highlight whitespace errors by setting wsErrorHighlight to all in the global git config.

$ git config --global diff.wsErrorHighlight all

Which updates the global gitconfig file with the following line:

[diff]
	wsErrorHighlight = all

The all option is a shorthand for old,new,context.

See man git-diff for more details.