swift-format provides some hidden command line options to facilitate
debugging the tool during development:
-
--debug-disable-pretty-print: Disables the pretty-printing pass of the formatter, causing only the syntax tree transformations in the first phase pipeline to run. -
--debug-dump-token-stream: Dumps a human-readable indented structure representing the pseudotoken stream constructed by the pretty printing phase.
The Scripts directory contains a format-diff.sh script
that some developers may find useful. When invoked, it rebuilds
swift-format (if necessary to pick up any recent changes) and lets
you view a side-by-side diff with the original file on the left side
and the formatted output on the right side.
This script will use colordiff if it is installed on your PATH;
otherwise, it will fall back to diff.