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/Prettier

Configuration File

Prettier uses cosmiconfig for configuration file support. This means you can configure Prettier via (in order of precedence):

A "prettier" key in your package.json file.
A .prettierrc file written in JSON or YAML.
A .prettierrc.json, .prettierrc.yml, .prettierrc.yaml, or .prettierrc.json5 file.
A .prettierrc.js, or prettier.config.js file that exports an object using export default or module.exports (depends on the type value in your package.json).
A .prettierrc.mjs, or prettier.config.mjs file that exports an object using export default.
A .prettierrc.cjs, or prettier.config.cjs file that exports an object using module.exports.
A .prettierrc.toml file.

The configuration file will be resolved starting from the location of the file being formatted, and searching up the file tree until a config file is (or isn’t) found.

Prettier intentionally doesn’t support any kind of global configuration. This is to make sure that when a project is copied to another computer, Prettier’s behavior stays the same. Otherwise, Prettier wouldn’t be able to guarantee that everybody in a team gets the same consistent results.

The options you can use in the configuration file are the same as the API options.

Basic Configuration

JSON:

{
  "trailingComma": "es5",
  "tabWidth": 4,
  "semi": false,
  "singleQuote": true
}

JS(ESM):

// prettier.config.js, .prettierrc.js, prettier.config.mjs, or .prettierrc.mjs

/** @type {import("prettier").Options} */
const config = {
  trailingComma: "es5",
  tabWidth: 4,
  semi: false,
  singleQuote: true,
};

export default config;

JS(CommonJS):

// prettier.config.js, .prettierrc.js, prettier.config.cjs, or .prettierrc.cjs

/** @type {import("prettier").Options} */
const config = {
  trailingComma: "es5",
  tabWidth: 4,
  semi: false,
  singleQuote: true,
};

module.exports = config;

YAML:

# .prettierrc or .prettierrc.yaml
trailingComma: "es5"
tabWidth: 4
semi: false
singleQuote: true

TOML:

# .prettierrc.toml
trailingComma = "es5"
tabWidth = 4
semi = false
singleQuote = true

Configuration Overrides

Overrides let you have different configuration for certain file extensions, folders and specific files.

Prettier borrows ESLint’s override format.

JSON:

{
  "semi": false,
  "overrides": [
    {
      "files": "*.test.js",
      "options": {
        "semi": true
      }
    },
    {
      "files": ["*.html", "legacy/**/*.js"],
      "options": {
        "tabWidth": 4
      }
    }
  ]
}

YAML:

semi: false
overrides:
  - files: "*.test.js"
    options:
      semi: true
  - files:
      - "*.html"
      - "legacy/**/*.js"
    options:
      tabWidth: 4

files is required for each override, and may be a string or array of strings. excludeFiles may be optionally provided to exclude files for a given rule, and may also be a string or array of strings.

Sharing a Prettier configuration is simple: just publish a module that exports a configuration object, say @company/prettier-config, and reference it in your package.json:

{
  "name": "my-cool-library",
  "version": "9000.0.1",
  "prettier": "@company/prettier-config"
}

If you don’t want to use package.json, you can use any of the supported extensions to export a string, e.g. .prettierrc.json:

"@company/prettier-config"

An example configuration repository is available here.

Note: This method does not offer a way to extend the configuration to overwrite some properties from the shared configuration. If you need to do that, import the file in a .prettierrc.js file and export the modifications, e.g:
import companyPrettierConfig from "@company/prettier-config";

export default {
  ...companyPrettierConfig,
  semi: false,
};

Setting the parser option

By default, Prettier automatically infers which parser to use based on the input file extension. Combined with overrides you can teach Prettier how to parse files it does not recognize.

For example, to get Prettier to format its own .prettierrc file, you can do:

{
  "overrides": [
    {
      "files": ".prettierrc",
      "options": { "parser": "json" }
    }
  ]
}

You can also switch to the flow parser instead of the default babel for .js files:

{
  "overrides": [
    {
      "files": "*.js",
      "options": {
        "parser": "flow"
      }
    }
  ]
}

Note: Never put the parser option at the top level of your configuration. Only use it inside overrides. Otherwise you effectively disable Prettier’s automatic file extension based parser inference. This forces Prettier to use the parser you specified for all types of files – even when it doesn’t make sense, such as trying to parse a CSS file as JavaScript.

Configuration Schema

If you’d like a JSON schema to validate your configuration, one is available here: http://json.schemastore.org/prettierrc.

EditorConfig

If options.editorconfig is true and an .editorconfig file is in your project, Prettier will parse it and convert its properties to the corresponding Prettier configuration. This configuration will be overridden by .prettierrc, etc.

Here’s an annotated description of how different properties map to Prettier’s behavior:

# Stop the editor from looking for .editorconfig files in the parent directories
# root = true

[*]
# Non-configurable Prettier behaviors
charset = utf-8
insert_final_newline = true
# Caveat: Prettier won’t trim trailing whitespace inside template strings, but your editor might.
# trim_trailing_whitespace = true

# Configurable Prettier behaviors
# (change these if your Prettier config differs)
end_of_line = lf
indent_style = space
indent_size = 2
max_line_length = 80

Here’s a copy+paste-ready .editorconfig file if you use the default options: