3 [![Build Status](https://img.shields.io/travis/davidtheclark/cosmiconfig/master.svg?label=unix%20build)](https://travis-ci.org/davidtheclark/cosmiconfig) [![Build status](https://img.shields.io/appveyor/ci/davidtheclark/cosmiconfig/master.svg?label=windows%20build)](https://ci.appveyor.com/project/davidtheclark/cosmiconfig/branch/master)
5 Find and load a configuration object from
6 - a `package.json` property (anywhere down the file tree)
7 - a JSON or YAML "rc file" (anywhere down the file tree)
8 - a `.config.js` CommonJS module (anywhere down the file tree)
9 - a CLI `--config` argument
11 For example, if your module's name is "soursocks," cosmiconfig will search out configuration in the following places:
12 - a `soursocks` property in `package.json` (anywhere down the file tree)
13 - a `.soursocksrc` file in JSON or YAML format (anywhere down the file tree)
14 - a `soursocks.config.js` file exporting a JS object (anywhere down the file tree)
15 - a CLI `--config` argument
17 cosmiconfig continues to search in these places all the way down the file tree until it finds acceptable configuration (or hits the home directory). And it does all this asynchronously, so it shouldn't get in your way.
19 Additionally, all of these search locations are configurable: you can customize filenames or turn off any location.
21 You can also look for rc files with extensions, e.g. `.soursocksrc.json` or `.soursocksrc.yaml`.
22 You may like extensions on your rc files because you'll get syntax highlighting and linting in text editors.
27 npm install cosmiconfig
35 var cosmiconfig = require('cosmiconfig');
37 var explorer = cosmiconfig(yourModuleName[, options]);
39 explorer.load(yourSearchPath)
41 // result.config is the parsed configuration object
42 // result.filepath is the path to the config file that was found
44 .catch((parsingError) => {
45 // do something constructive
49 The function `cosmiconfig()` searches for a configuration object and returns a Promise,
50 which resolves with an object containing the information you're looking for.
52 So let's say `var yourModuleName = 'goldengrahams'` — here's how cosmiconfig will work:
54 - Starting from `process.cwd()` (or some other directory defined by the `searchPath` argument to `load()`), it looks for configuration objects in three places, in this order:
55 1. A `goldengrahams` property in a `package.json` file (or some other property defined by `options.packageProp`);
56 2. A `.goldengrahamsrc` file with JSON or YAML syntax (or some other filename defined by `options.rc`);
57 3. A `goldengrahams.config.js` JS file exporting the object (or some other filename defined by `options.js`).
58 - If none of those searches reveal a configuration object, it moves down one directory and tries again. So the search continues in `./`, `../`, `../../`, `../../../`, etc., checking those three locations in each directory.
59 - It continues searching until it arrives at your home directory (or some other directory defined by `options.stopDir`).
60 - If at any point a parseable configuration is found, the `cosmiconfig()` Promise resolves with its result object.
61 - If no configuration object is found, the `cosmiconfig()` Promise resolves with `null`.
62 - If a configuration object is found *but is malformed* (causing a parsing error), the `cosmiconfig()` Promise rejects and shares that error (so you should `.catch()` it).
64 All this searching can be short-circuited by passing `options.configPath` or a `--config` CLI argument to specify a file.
65 cosmiconfig will read that file and try parsing it as JSON, YAML, or JS.
69 As of v2, cosmiconfig uses a few caches to reduce the need for repetitious reading of the filesystem. Every new cosmiconfig instance (created with `cosmiconfig()`) has its own caches.
71 To avoid or work around caching, you can
72 - create separate instances of cosmiconfig, or
73 - set `cache: false` in your options.
74 - use the cache clearing methods documented below.
78 ### `var explorer = cosmiconfig(moduleName[, options])`
80 Creates a cosmiconfig instance (i.e. explorer) configured according to the arguments, and initializes its caches.
86 You module name. This is used to create the default filenames that cosmiconfig will look for.
92 Type: `string` or `false`
93 Default: `'[moduleName]'`
95 Name of the property in `package.json` to look for.
97 If `false`, cosmiconfig will not look in `package.json` files.
101 Type: `string` or `false`
102 Default: `'.[moduleName]rc'`
104 Name of the "rc file" to look for, which can be formatted as JSON or YAML.
106 If `false`, cosmiconfig will not look for an rc file.
108 If `rcExtensions: true`, the rc file can also have extensions that specify the syntax, e.g. `.[moduleName]rc.json`.
109 You may like extensions on your rc files because you'll get syntax highlighting and linting in text editors.
110 Also, with `rcExtensions: true`, you can use JS modules as rc files, e.g. `.[moduleName]rc.js`.
114 Type: `string` or `false`
115 Default: `'[moduleName].config.js'`
117 Name of a JS file to look for, which must export the configuration object.
119 If `false`, cosmiconfig will not look for a JS file.
123 Type: `string` or `false`
126 Name of a `process.argv` argument to look for, whose value should be the path to a configuration file.
127 cosmiconfig will read the file and try to parse it as JSON, YAML, or JS.
128 By default, cosmiconfig looks for `--config`.
130 If `false`, cosmiconfig will not look for any `process.argv` arguments.
137 If `true`, cosmiconfig will expect rc files to be strict JSON. No YAML permitted, and no sloppy JSON.
139 By default, rc files are parsed with [js-yaml](https://github.com/nodeca/js-yaml), which is
140 more permissive with punctuation than standard strict JSON.
147 If `true`, cosmiconfig will look for rc files with extensions, in addition to rc files without.
149 This adds a few steps to the search process.
150 Instead of *just* looking for `.goldengrahamsrc` (no extension), it will also look for the following, in this order:
152 - `.goldengrahamsrc.json`
153 - `.goldengrahamsrc.yaml`
154 - `.goldengrahamsrc.yml`
155 - `.goldengrahamsrc.js`
160 Default: Absolute path to your home directory
162 Directory where the search will stop.
169 If `false`, no caches will be used.
173 Type: `Function` returning a Promise
175 A function that transforms the parsed configuration. Receives the result object with `config` and `filepath` properties, and must return a Promise that resolves with the transformed result.
177 The reason you might use this option instead of simply applying your transform function some other way is that *the transformed result will be cached*. If your transformation involves additional filesystem I/O or other potentially slow processing, you can use this option to avoid repeating those steps every time a given configuration is loaded.
179 ### Instance methods (on `explorer`)
181 #### `load([searchPath, configPath])`
183 Find and load a configuration file. Returns `null` if nothing is found, or an object with two properties:
184 - `config`: The loaded and parsed configuration.
185 - `filepath`: The filepath where this configuration was found.
187 You should provide *either* `searchPath` *or* `configPath`. Use `configPath` if you know the path of the configuration file you want to load. Otherwise, use `searchPath`.
190 explorer.load('start/search/here');
191 explorer.load('start/search/at/this/file.css');
193 explorer.load(null, 'load/this/file.json');
196 If you provide `searchPath`, cosmiconfig will start its search at `searchPath` and continue to search up the file tree, as documented above.
198 If you provide `configPath` (i.e. you already know where the configuration is that you want to load), cosmiconfig will try to read and parse that file.
200 #### `clearFileCache()`
202 Clears the cache used when you provide a `configPath` argument to `load`.
204 #### `clearDirectoryCache()`
206 Clears the cache used when you provide a `searchPath` argument to `load`.
210 Performs both `clearFileCache()` and `clearDirectoryCache()`.
212 ## Differences from [rc](https://github.com/dominictarr/rc)
214 [rc](https://github.com/dominictarr/rc) serves its focused purpose well. cosmiconfig differs in a few key ways — making it more useful for some projects, less useful for others:
216 - Looks for configuration in some different places: in a `package.json` property, an rc file, a `.config.js` file, and rc files with extensions.
217 - Built-in support for JSON, YAML, and CommonJS formats.
218 - Stops at the first configuration found, instead of finding all that can be found down the filetree and merging them automatically.
222 ## Contributing & Development
224 Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.
226 And please do participate!