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    conf
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    10.0.0 • Public • Published

    conf

    Simple config handling for your app or module

    All you have to care about is what to persist. This module will handle all the dull details like where and how.

    It does not support multiple processes writing to the same store.
    I initially made this tool to let command-line tools persist some data.

    If you need this for Electron, check out electron-store instead.

    Install

    $ npm install conf
    

    Usage

    const Conf = require('conf');
    
    const config = new Conf();
    
    config.set('unicorn', '🦄');
    console.log(config.get('unicorn'));
    //=> '🦄'
    
    // Use dot-notation to access nested properties
    config.set('foo.bar', true);
    console.log(config.get('foo'));
    //=> {bar: true}
    
    config.delete('unicorn');
    console.log(config.get('unicorn'));
    //=> undefined

    Or create a subclass.

    API

    Changes are written to disk atomically, so if the process crashes during a write, it will not corrupt the existing config.

    Conf(options?)

    Returns a new instance.

    options

    Type: object

    defaults

    Type: object

    Default values for the config items.

    Note: The values in defaults will overwrite the default key in the schema option.

    schema

    Type: object

    JSON Schema to validate your config data.

    Under the hood, the JSON Schema validator ajv is used to validate your config. We use JSON Schema draft-07 and support all validation keywords and formats.

    You should define your schema as an object where each key is the name of your data's property and each value is a JSON schema used to validate that property. See more here.

    Example:

    const Conf = require('conf');
    
    const schema = {
    	foo: {
    		type: 'number',
    		maximum: 100,
    		minimum: 1,
    		default: 50
    	},
    	bar: {
    		type: 'string',
    		format: 'url'
    	}
    };
    
    const config = new Conf({schema});
    
    console.log(config.get('foo'));
    //=> 50
    
    config.set('foo', '1');
    // [Error: Config schema violation: `foo` should be number]

    Note: The default value will be overwritten by the defaults option if set.

    migrations

    Type: object

    You can use migrations to perform operations to the store whenever a project version is upgraded.

    The migrations object should consist of a key-value pair of 'version': handler. The version can also be a semver range.

    Example:

    const Conf = require('conf');
    
    const store = new Conf({
    	migrations: {
    		'0.0.1': store => {
    			store.set('debugPhase', true);
    		},
    		'1.0.0': store => {
    			store.delete('debugPhase');
    			store.set('phase', '1.0.0');
    		},
    		'1.0.2': store => {
    			store.set('phase', '1.0.2');
    		},
    		'>=2.0.0': store => {
    			store.set('phase', '>=2.0.0');
    		}
    	}
    });

    Note: The version the migrations use refers to the project version by default. If you want to change this behavior, specify the projectVersion option.

    configName

    Type: string
    Default: 'config'

    Name of the config file (without extension).

    Useful if you need multiple config files for your app or module. For example, different config files between two major versions.

    projectName

    Type: string
    Default: The name field in the package.json closest to where conf is imported.

    You only need to specify this if you don't have a package.json file in your project or if it doesn't have a name defined within it.

    projectVersion

    Type: string
    Default: The version field in the package.json closest to where conf is imported.

    You only need to specify this if you don't have a package.json file in your project or if it doesn't have a version defined within it.

    cwd

    Type: string
    Default: System default user config directory

    You most likely don't need this. Please don't use it unless you really have to. By default, it will pick the optimal location by adhering to system conventions. You are very likely to get this wrong and annoy users.

    Overrides projectName.

    The only use-case I can think of is having the config located in the app directory or on some external storage.

    encryptionKey

    Type: string | Buffer | TypedArray | DataView
    Default: undefined

    This can be used to secure sensitive data if the encryption key is stored in a secure manner (not plain-text) in the Node.js app. For example, by using node-keytar to store the encryption key securely, or asking the encryption key from the user (a password) and then storing it in a variable.

    In addition to security, this could be used for obscurity. If a user looks through the config directory and finds the config file, since it's just a JSON file, they may be tempted to modify it. By providing an encryption key, the file will be obfuscated, which should hopefully deter any users from doing so.

    It also has the added bonus of ensuring the config file's integrity. If the file is changed in any way, the decryption will not work, in which case the store will just reset back to its default state.

    When specified, the store will be encrypted using the aes-256-cbc encryption algorithm.

    fileExtension

    Type: string
    Default: 'json'

    Extension of the config file.

    You would usually not need this, but could be useful if you want to interact with a file with a custom file extension that can be associated with your app. These might be simple save/export/preference files that are intended to be shareable or saved outside of the app.

    clearInvalidConfig

    Type: boolean
    Default: false

    The config is cleared if reading the config file causes a SyntaxError. This is a good behavior for unimportant data, as the config file is not intended to be hand-edited, so it usually means the config is corrupt and there's nothing the user can do about it anyway. However, if you let the user edit the config file directly, mistakes might happen and it could be more useful to throw an error when the config is invalid instead of clearing.

    serialize

    Type: Function
    Default: value => JSON.stringify(value, null, '\t')

    Function to serialize the config object to a UTF-8 string when writing the config file.

    You would usually not need this, but it could be useful if you want to use a format other than JSON.

    deserialize

    Type: Function
    Default: JSON.parse

    Function to deserialize the config object from a UTF-8 string when reading the config file.

    You would usually not need this, but it could be useful if you want to use a format other than JSON.

    projectSuffix

    Type: string
    Default: 'nodejs'

    You most likely don't need this. Please don't use it unless you really have to.

    Suffix appended to projectName during config file creation to avoid name conflicts with native apps.

    You can pass an empty string to remove the suffix.

    For example, on macOS, the config file will be stored in the ~/Library/Preferences/foo-nodejs directory, where foo is the projectName.

    accessPropertiesByDotNotation

    Type: boolean
    Default: true

    Accessing nested properties by dot notation. For example:

    const Conf = require('conf');
    
    const config = new Conf();
    
    config.set({
    	foo: {
    		bar: {
    			foobar: '🦄'
    		}
    	}
    });
    
    console.log(config.get('foo.bar.foobar'));
    //=> '🦄'

    Alternatively, you can set this option to false so the whole string would be treated as one key.

    const Conf = require('conf');
    
    const config = new Conf({accessPropertiesByDotNotation: false});
    
    config.set({
    	`foo.bar.foobar`: '🦄'
    });
    
    console.log(config.get('foo.bar.foobar'));
    //=> '🦄'

    watch

    type: boolean
    Default: false

    Watch for any changes in the config file and call the callback for onDidChange or onDidAnyChange if set. This is useful if there are multiple processes changing the same config file.

    Instance

    You can use dot-notation in a key to access nested properties.

    The instance is iterable so you can use it directly in a for…of loop.

    .set(key, value)

    Set an item.

    The value must be JSON serializable. Trying to set the type undefined, function, or symbol will result in a TypeError.

    .set(object)

    Set multiple items at once.

    .get(key, defaultValue?)

    Get an item or defaultValue if the item does not exist.

    .reset(...keys)

    Reset items to their default values, as defined by the defaults or schema option.

    Use .clear() to reset all items.

    .has(key)

    Check if an item exists.

    .delete(key)

    Delete an item.

    .clear()

    Delete all items.

    This resets known items to their default values, if defined by the defaults or schema option.

    .onDidChange(key, callback)

    callback: (newValue, oldValue) => {}

    Watches the given key, calling callback on any changes.

    When a key is first set oldValue will be undefined, and when a key is deleted newValue will be undefined.

    Returns a function which you can use to unsubscribe:

    const unsubscribe = conf.onDidChange(key, callback);
    
    unsubscribe();

    .onDidAnyChange(callback)

    callback: (newValue, oldValue) => {}

    Watches the whole config object, calling callback on any changes.

    oldValue and newValue will be the config object before and after the change, respectively. You must compare oldValue to newValue to find out what changed.

    Returns a function which you can use to unsubscribe:

    const unsubscribe = conf.onDidAnyChange(callback);
    
    unsubscribe();

    .size

    Get the item count.

    .store

    Get all the config as an object or replace the current config with an object:

    conf.store = {
    	hello: 'world'
    };

    .path

    Get the path to the config file.

    FAQ

    How is this different from configstore?

    I'm also the author of configstore. While it's pretty good, I did make some mistakes early on that are hard to change at this point. This module is the result of everything I learned from making configstore. Mainly where the config is stored. In configstore, the config is stored in ~/.config (which is mainly a Linux convention) on all systems, while conf stores config in the system default user config directory. The ~/.config directory, it turns out, often have an incorrect permission on macOS and Windows, which has caused a lot of grief for users.

    Can I use YAML or another serialization format?

    The serialize and deserialize options can be used to customize the format of the config file, as long as the representation is compatible with utf8 encoding.

    Example using YAML:

    const Conf = require('conf');
    const yaml = require('js-yaml');
    
    const config = new Conf({
    	fileExtension: 'yaml',
    	serialize: yaml.safeDump,
    	deserialize: yaml.safeLoad
    });

    Related

    • electron-store - Simple data persistence for your Electron app or module
    • cache-conf - Simple cache config handling for your app or module

    Install

    npm i conf

    DownloadsWeekly Downloads

    367,063

    Version

    10.0.0

    License

    MIT

    Unpacked Size

    45.3 kB

    Total Files

    7

    Last publish

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