Question

Run Prettier through the CLI with this script. Run it without any arguments to see the options.

To format a file in-place, use --write. You may want to consider committing your code before doing that, just in case.

prettier [opts] [filename ...]

In practice, this may look something like:

prettier --single-quote --trailing-comma es5 --write "{app,__{tests,mocks}__}/**/*.js"

Don't forget the quotes around the globs! The quotes make sure that Prettier expands the globs rather than your shell, for cross-platform usage. The glob syntax from the glob module is used.

Prettier CLI will ignore files located in node_modules directory. To opt-out from this behavior use --with-node-modules flag.

--check

When you want to check if your files are formatted, you can run Prettier with the --check flag (or -c). This will output a human-friendly message and a list of unformatted files, if any.

prettier --check "src/**/*.js"

Console output if all files are formatted:

Checking formatting...
All matched files use Prettier code style!

Console output if some of the files require re-formatting:

Checking formatting...
src/fileA.js
src/fileB.js
Code style issues found in the above file(s). Forgot to run Prettier?

The command will return exit code 1 in the second case, which is helpful inside the CI pipelines. Human-friendly status messages help project contributors react on possible problems. To minimise the number of times prettier --check finds unformatted files, you may be interested in configuring a pre-commit hook in your repo. Applying this practice will minimise the number of times the CI fails because of code formatting problems.

If you need to pipe the list of unformatted files to another command, you can use --list-different flag instead of --check.

Exit codes

Code	Information
0	Everything formatted properly
1	Something wasn't formatted properly
2	Something's wrong with Prettier

--debug-check

If you're worried that Prettier will change the correctness of your code, add --debug-check to the command. This will cause Prettier to print an error message if it detects that code correctness might have changed. Note that --write cannot be used with --debug-check.

--find-config-path and --config

If you are repeatedly formatting individual files with prettier, you will incur a small performance cost when prettier attempts to look up a configuration file. In order to skip this, you may ask prettier to find the config file once, and re-use it later on.

prettier --find-config-path ./my/file.js
./my/.prettierrc

This will provide you with a path to the configuration file, which you can pass to --config:

prettier --config ./my/.prettierrc --write ./my/file.js

You can also use --config if your configuration file lives somewhere where prettier cannot find it, such as a config/ directory.

If you don't have a configuration file, or want to ignore it if it does exist, you can pass --no-config instead.

--ignore-path

Path to a file containing patterns that describe files to ignore. By default, prettier looks for ./.prettierignore.

--require-pragma

Require a special comment, called a pragma, to be present in the file's first docblock comment in order for prettier to format it.

/**
 * @prettier
 */

Valid pragmas are @prettier and @format.

--insert-pragma

Insert a @format pragma to the top of formatted files when pragma is absent. Works well when used in tandem with --require-pragma.

--list-different

Another useful flag is --list-different (or -l) which prints the filenames of files that are different from Prettier formatting. If there are differences the script errors out, which is useful in a CI scenario.

prettier --single-quote --list-different "src/**/*.js"

You can also use --check flag, which works the same way as --list-different, but also prints a human-friendly summary message to stdout.

--no-config

Do not look for a configuration file. The default settings will be used.

--config-precedence

Defines how config file should be evaluated in combination of CLI options.

cli-override (default)

CLI options take precedence over config file

file-override

Config file take precedence over CLI options

prefer-file

If a config file is found will evaluate it and ignore other CLI options. If no config file is found CLI options will evaluate as normal.

This option adds support to editor integrations where users define their default configuration but want to respect project specific configuration.

--no-editorconfig

Don't take .editorconfig into account when parsing configuration. See the prettier.resolveConfig docs for details.

--with-node-modules

Prettier CLI will ignore files located in node_modules directory. To opt-out from this behavior use --with-node-modules flag.

--write

This rewrites all processed files in place. This is comparable to the eslint --fix workflow.

--loglevel

Change the level of logging for the CLI. Valid options are:

• error
• warn
• log (default)
• debug
• silent

--stdin-filepath

A path to the file that the Prettier CLI will treat like stdin. For example:

abc.css

.name {
  display: none;
}

shell

$ cat abc.css | prettier --stdin-filepath abc.css
.name {
  display: none;
}