Find and load a configuration object from
- a
package.json
property (anywhere up the directory tree) - a JSON or YAML "rc file" (anywhere up the directory tree)
- a
.config.js
CommonJS module (anywhere up the directory tree)
For example, if your module's name is "soursocks," cosmiconfig will search out configuration in the following places:
- a
soursocks
property inpackage.json
(anywhere up the directory tree) - a
.soursocksrc
file in JSON or YAML format (anywhere up the directory tree) - a
soursocks.config.js
file exporting a JS object (anywhere up the directory tree)
cosmiconfig continues to search in these places all the way up the directory tree until it finds acceptable configuration (or hits the home directory).
Additionally, all of these search locations are configurable: you can customize filenames or turn off any location.
You can also look for rc files with extensions, e.g. .soursocksrc.json
or .soursocksrc.yaml
.
You may like extensions on your rc files because you'll get syntax highlighting and linting in text editors.
npm install cosmiconfig
Tested in Node 4+.
var cosmiconfig = require('cosmiconfig');
var explorer = cosmiconfig(yourModuleName[, options]);
explorer.load()
.then((result) => {
// result.config is the parsed configuration object
// result.filepath is the path to the config file that was found
})
.catch((parsingError) => {
// do something constructive
});
The function cosmiconfig()
searches for a configuration object and returns a Promise,
which resolves with an object containing the information you're looking for.
You can also pass option sync: true
to load the config synchronously, returning the config itself.
So let's say var yourModuleName = 'goldengrahams'
— here's how cosmiconfig will work:
- Starting from
process.cwd()
(or some other directory defined by thesearchPath
argument toload()
), it looks for configuration objects in three places, in this order:- A
goldengrahams
property in apackage.json
file (or some other property defined byoptions.packageProp
); - A
.goldengrahamsrc
file with JSON or YAML syntax (or some other filename defined byoptions.rc
); - A
goldengrahams.config.js
JS file exporting the object (or some other filename defined byoptions.js
).
- A
- If none of those searches reveal a configuration object, it moves up one directory level and tries again. So the search continues in
./
,../
,../../
,../../../
, etc., checking those three locations in each directory. - It continues searching until it arrives at your home directory (or some other directory defined by
options.stopDir
). - If at any point a parseable configuration is found, the
cosmiconfig()
Promise resolves with its result object. - If no configuration object is found, the
cosmiconfig()
Promise resolves withnull
. - 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).
All this searching can be short-circuited by passing options.configPath
to specify a file.
cosmiconfig will read that file and try parsing it as JSON, YAML, or JS.
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.
To avoid or work around caching, you can
- create separate instances of cosmiconfig, or
- set
cache: false
in your options. - use the cache clearing methods documented below.
Creates a cosmiconfig instance (i.e. explorer) configured according to the arguments, and initializes its caches.
Type: string
You module name. This is used to create the default filenames that cosmiconfig will look for.
Type: string
or false
Default: '[moduleName]'
Name of the property in package.json
to look for.
If false
, cosmiconfig will not look in package.json
files.
Type: string
or false
Default: '.[moduleName]rc'
Name of the "rc file" to look for, which can be formatted as JSON or YAML.
If false
, cosmiconfig will not look for an rc file.
If rcExtensions: true
, the rc file can also have extensions that specify the syntax, e.g. .[moduleName]rc.json
.
You may like extensions on your rc files because you'll get syntax highlighting and linting in text editors.
Also, with rcExtensions: true
, you can use JS modules as rc files, e.g. .[moduleName]rc.js
.
Type: string
or false
Default: '[moduleName].config.js'
Name of a JS file to look for, which must export the configuration object.
If false
, cosmiconfig will not look for a JS file.
Type: boolean
Default: false
If true
, cosmiconfig will expect rc files to be strict JSON. No YAML permitted, and no sloppy JSON.
By default, rc files are parsed with js-yaml, which is more permissive with punctuation than standard strict JSON.
Type: boolean
Default: false
If true
, cosmiconfig will look for rc files with extensions, in addition to rc files without.
This adds a few steps to the search process.
Instead of just looking for .goldengrahamsrc
(no extension), it will also look for the following, in this order:
.goldengrahamsrc.json
.goldengrahamsrc.yaml
.goldengrahamsrc.yml
.goldengrahamsrc.js
Type: string
Default: Absolute path to your home directory
Directory where the search will stop.
Type: boolean
Default: true
If false
, no caches will be used.
Type: boolean
Default: false
If true
, config will be loaded synchronously.
Type: Function
A function that transforms the parsed configuration. Receives the result object with config
and filepath
properties.
If the option sync
is false
(default), the function must return a Promise that resolves with the transformed result.
If the option sync
is true
, though, transform
should be a synchronous function which returns the transformed result.
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.
Type: string
If provided, cosmiconfig will load and parse a config from this path, and will not perform its usual search.
Type: 'json' | 'yaml' | 'js'
The expected file format for the config loaded from configPath
.
If not specified, cosmiconfig will try to infer the format using the extension name (if it has one). In the event that the file does not have an extension or the extension is unrecognized, cosmiconfig will try to parse it as a JSON, YAML, or JS file.
Find and load a configuration file. Returns a Promise that resolves with null
, if nothing is found, or an object with two properties:
config
: The loaded and parsed configuration.filepath
: The filepath where this configuration was found.
You should provide either searchPath
or configPath
. Use configPath
if you know the path of the configuration file you want to load. Note that configPath
takes priority over searchPath
if both parameters are specified.
explorer.load()
explorer.load('start/search/here');
explorer.load('start/search/at/this/file.css');
explorer.load(null, 'load/this/file.json');
If you provide searchPath
, cosmiconfig will start its search at searchPath
and continue to search up the directory tree, as documented above.
By default, searchPath
is set to process.cwd()
.
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. Note that the format
option is applicable for this as well.
Clears the cache used when you provide a configPath
argument to load
.
Clears the cache used when you provide a searchPath
argument to load
.
Performs both clearFileCache()
and clearDirectoryCache()
.
Differences from rc
rc serves its focused purpose well. cosmiconfig differs in a few key ways — making it more useful for some projects, less useful for others:
- Looks for configuration in some different places: in a
package.json
property, an rc file, a.config.js
file, and rc files with extensions. - Built-in support for JSON, YAML, and CommonJS formats.
- Stops at the first configuration found, instead of finding all that can be found up the directory tree and merging them automatically.
- Options.
- Asynchronous by default (though can be run synchronously).
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.
And please do participate!