Load a directory diff of changes Prettier would make

The Prettier code formatter can list which files will change but does not provide an easy way to inspect all changes that will be made. This command line tool will take a copy of the source directory, apply Prettier to the copy and then open a directory diff showing the changes.

Meld is used by default to display the diff but a different diff program can be specified in the arguments.

Note: Only GUI diff tools are currently supported.

Installation

npm install prettier-compare-cli --global
# Or if using Yarn:
yarn global add prettier-compare-cli

The following applications must be available on the path:

• Prettier
• Meld (if the difftool argument isn't provided)

Example usage

Run the comparison using a specific configuration:

prettier-compare --src /Git/my-project --config /Git/my-project/prettier.config.js

Not passing the config argument will call Prettier with the no-config option.

prettier-compare --src /Git/my-project

Specify that Prettier should only be called on js and jsx files.

prettier-compare --src /Git/my-project --extensions js,jsx

Command line arguments

Argument | Description ---------- | ---------------------------------------------- src | Path to source directory config | Path to the Prettier config file (optional) extensions | Comma separated list of extensions (optional) difftool | The directory diff command (optional)

Any program where the pattern $difftool $directoryA $directoryB will open a directory diff should work. Programs that output the diff to stdout won't current work as the output isn't being captured.

Configuring Meld

This program will exclude git. and node_modules from being copied and processed by Prettier but it can't exclude those directories from appearing in the resulting diff. That setting needs to be made in Meld by going into preferences and adding a new pattern to the file filters.

Name | Pattern ------------ | ------------ Node modules | node_modules

(The .git directory should already be getting excluded).