feat: replace cosmiconfig with lilconfig + yaml to reduce dependencies

Author: iiroj

README.md

@@ -114,9 +114,7 @@ Starting with v3.1 you can now use different ways of configuring lint-staged:
   whether your project's _package.json_ contains the `"type": "module"` option or not.
 - Pass a configuration file using the `--config` or `-c` flag
 
-See [cosmiconfig](https://github.com/davidtheclark/cosmiconfig) for more details on what formats are supported.
-
-Configuration should be an object where each value is a command to run and its key is a glob pattern to use for this command. This package uses [micromatch](https://github.com/micromatch/micromatch) for glob patterns.
+Configuration should be an object where each value is a command to run and its key is a glob pattern to use for this command. This package uses [micromatch](https://github.com/micromatch/micromatch) for glob patterns. JavaScript files can also export advanced configuration as a function. See [Using JS configuration files](#using-js-configuration-files) for more info.
 
 #### `package.json` example:
 
@@ -202,7 +200,7 @@ For example:
 
 going to execute `eslint` and if it exits with `0` code, it will execute `prettier --write` on all staged `*.js` files.
 
-## Using JS configuration file
+## Using JS configuration files
 
 Writing the configuration file in JavaScript is the most powerful way to configure lint-staged (`lint-staged.config.js`, [similar](https://github.com/okonet/lint-staged/README.md#configuration), or passed via `--config`). From the configuration file, you can export either a single function or an object.
 

lib/index.js

@@ -58,21 +58,19 @@ const lintStaged = async (
 ) => {
   await validateOptions({ shell }, logger)
 
-  debugLog('Loading config using `cosmiconfig`')
+  debugLog('Loading config using `lilconfig`')
 
   const resolved = configObject
     ? { config: configObject, filepath: '(input)' }
     : await loadConfig(configPath)
 
-  if (resolved == null) {
+  if (!resolved) {
     logger.error(`${ConfigNotFoundError.message}.`)
     throw ConfigNotFoundError
   }
 
   debugLog('Successfully loaded config from `%s`:\n%O', resolved.filepath, resolved.config)
 
-  // resolved.config is the parsed configuration object
-  // resolved.filepath is the path to the config file that was found
   const config = validateConfig(resolved.config, logger)
 
   if (debug) {

lib/loadConfig.js

@@ -1,9 +1,44 @@
-import { cosmiconfig } from 'cosmiconfig'
+import { lilconfig } from 'lilconfig'
+import YAML from 'yaml'
+
+/**
+ * The list of files `lint-staged` will read configuration
+ * from, in the declared order.
+ */
+const searchPlaces = [
+  'package.json',
+  '.lintstagedrc',
+  '.lintstagedrc.json',
+  '.lintstagedrc.yaml',
+  '.lintstagedrc.yml',
+  '.lintstagedrc.mjs',
+  '.lintstagedrc.js',
+  '.lintstagedrc.cjs',
+  'lint-staged.config.mjs',
+  'lint-staged.config.js',
+  'lint-staged.config.cjs',
+]
 
 const dynamicImport = (path) => import(path).then((module) => module.default)
 
 const jsonParse = (path, content) => JSON.parse(content)
 
+/**
+ * `lilconfig` doesn't support yaml files by default,
+ * so we add custom loaders for those. Files without
+ * an extensions are assumed to be yaml — this
+ * assumption is in `cosmiconfig` as well.
+ */
+const loaders = {
+  '.js': dynamicImport,
+  '.json': jsonParse,
+  '.mjs': dynamicImport,
+  '.cjs': dynamicImport,
+  '.yaml': YAML.parse,
+  '.yml': YAML.parse,
+  noExt: YAML.parse,
+}
+
 const resolveConfig = (configPath) => {
   try {
     return require.resolve(configPath)
@@ -16,27 +51,6 @@ const resolveConfig = (configPath) => {
  * @param {string} [configPath]
  */
 export const loadConfig = (configPath) => {
-  const explorer = cosmiconfig('lint-staged', {
-    searchPlaces: [
-      'package.json',
-      '.lintstagedrc',
-      '.lintstagedrc.json',
-      '.lintstagedrc.yaml',
-      '.lintstagedrc.yml',
-      '.lintstagedrc.mjs',
-      '.lintstagedrc.js',
-      '.lintstagedrc.cjs',
-      'lint-staged.config.mjs',
-      'lint-staged.config.js',
-      'lint-staged.config.cjs',
-    ],
-    loaders: {
-      '.cjs': dynamicImport,
-      '.js': dynamicImport,
-      '.json': jsonParse,
-      '.mjs': dynamicImport,
-    },
-  })
-
+  const explorer = lilconfig('lint-staged', { searchPlaces, loaders })
   return configPath ? explorer.load(resolveConfig(configPath)) : explorer.search()
 }

lib/symbols.js

@@ -1,6 +1,10 @@
 export const ApplyEmptyCommitError = Symbol('ApplyEmptyCommitError')
 
-export const ConfigNotFoundError = new Error('Config could not be found')
+export const ConfigNotFoundError = new Error('Configuration could not be found')
+
+export const ConfigFormatError = new Error('Configuration should be an object or a function')
+
+export const ConfigEmptyError = new Error('Configuration should not be empty')
 
 export const GetBackupStashError = Symbol('GetBackupStashError')
 

lib/validateConfig.js

@@ -1,6 +1,7 @@
 import debug from 'debug'
 
 import { configurationError } from './messages.js'
+import { ConfigEmptyError, ConfigFormatError } from './symbols.js'
 import { validateBraces } from './validateBraces.js'
 
 const debugLog = debug('lint-staged:validateConfig')
@@ -27,7 +28,7 @@ export const validateConfig = (config, logger) => {
   debugLog('Validating config')
 
   if (!config || (typeof config !== 'object' && typeof config !== 'function')) {
-    throw new Error('Configuration should be an object or a function!')
+    throw ConfigFormatError
   }
 
   /**
@@ -42,7 +43,7 @@ export const validateConfig = (config, logger) => {
   }
 
   if (Object.entries(config).length === 0) {
-    throw new Error('Configuration should not be empty!')
+    throw ConfigEmptyError
   }
 
   const errors = []