rc-config-loader

What is rc-config-loader?

The rc-config-loader package is a utility for loading configuration files in various formats (like JSON, YAML, or JavaScript) from a project's root directory. It is particularly useful for applications that need to support user-defined configurations.

What are rc-config-loader's main functionalities?

Load Configuration

This feature allows you to load configuration files for a given application name. The loader will search for configuration files in the project's root directory and return the configuration object.

const rcConfigLoader = require('rc-config-loader');
const config = rcConfigLoader('myapp');
console.log(config);

Support for Multiple File Formats

The rc-config-loader supports multiple file formats such as JSON, YAML, and JavaScript. It will automatically detect and parse the configuration file based on its extension.

const rcConfigLoader = require('rc-config-loader');
const config = rcConfigLoader('myapp');
console.log(config);

Custom Configuration Path

You can specify a custom configuration file name or path if the default naming convention does not suit your needs.

const rcConfigLoader = require('rc-config-loader');
const config = rcConfigLoader('myapp', { configFileName: 'custom-config' });
console.log(config);

Other packages similar to rc-config-loader

cosmiconfig

Cosmiconfig is a versatile configuration loader that searches for configuration files in various formats (JSON, YAML, JS, etc.) and locations. It offers more flexibility and customization options compared to rc-config-loader.

config

The config package provides a more structured approach to configuration management, supporting environment-specific configurations and hierarchical settings. It is more feature-rich but also more complex than rc-config-loader.

dotenv

Dotenv is a simpler package focused on loading environment variables from a .env file into process.env. While it doesn't support multiple file formats or complex configurations, it is very useful for managing environment-specific settings.

README

rc-config-loader

Load config from .{product}rc.{json,yml,js} file.

It is a Node.js library for loading .textlintrc, .eslintrc, .stylelintrc etc...

Features

Find and load a configuration object from:

• a package.json property if it is needed
• a JSON or YAML, JS "rc file"
  • .<product>rc or .<product>rc.json or .<product>rc.js or.<product>rc.yml, .<product>rc.yaml
• TypeScript support
  • Includes .d.ts

Difference

with MoOx/rc-loader

• Safe API
  • rc contains shabang in .js file
• Enhance Error message

with cosmiconfig

• Sync loading
  • cosmiconfig@3+ support sync option
• Built-in TypeScript support
  • comisconfig@6* is written by TypeScript

If you want to async support and customize loader, recommended to use cosmiconfig.

Install

Install with npm:

npm install rc-config-loader

Usage

API

export interface rcConfigLoaderOption {
    // does look for `package.json`
    packageJSON?:
        | boolean
        | {
              fieldName: string;
          };
    // if config file name is not same with packageName, set the name
    configFileName?: string;
    // treat default(no ext file) as some extension
    defaultExtension?: string | string[];
    // where start to load
    cwd?: string;
}
/**
 * Find and load rcfile, return { config, filePath }
 * If not found any rcfile, throw an Error.
 * @param {string} pkgName
 * @param {rcConfigLoaderOption} [opts]
 * @returns {{ config: Object, filePath:string } | undefined}
 */
export declare function rcFile<R extends {}>(pkgName: string, opts?: rcConfigLoaderOption): {
    config: R;
    filePath: string;
} | undefined;

rcFile return { config, filePath } object.

• config: it is config object
• filePath: absolute path to config file

Note:

• rcFile function return undefined if the config file is not found
• rcFile throw an Error if the config file content is malformed (causing a parsing error)

Recommenced usage:

import { rcFile } from "rc-config-loader"

function loadRcFile(rcFileName){
    try {
        const results = rcFile(rcFileName);
        // Not Found
        if (!results) {
            return {};
        }
        return results.config;
    } catch (error) {
        // Found it, but it is parsing error
        return {} ; // default value
    }
}
// load config
const config = loadRcFile("your-application");
console.log(config); // => rcfile content

It will check these files and return config file if found it.

• .your-applicationrc.json
• .your-applicationrc.yml
• .your-applicationrc.yaml
• .your-applicationrc.js
• [optional] package.json
  • if packageJSON option is enabled

Example

import { rcFile } from "rc-config-loader"
// load .eslintrc from current dir
console.log(rcFile("eslint"));

// load .eslintrc from specific path
console.log(rcFile("eslint", {
    configFileName: `${__dirname}/test/fixtures/.eslintrc`
}));
/*
config: { extends: 'standard',
  rules:
   { 'comma-dangle': [ 2, 'always-multiline' ],
     'arrow-parens': [ 2, 'as-needed' ] } }
filePath: ${__dirname}/test/fixtures/.eslintrc
 */

// load property from package.json
console.log(rcFile("rc-config-loader", {
    packageJSON: {
        fieldName: "directories"
    }
}));
/*
config: { test: 'test' }
filePath: /path/to/package.json
 */

// load .eslintrc from specific dir
console.log(rcFile("eslint", {
    cwd: `${__dirname}/test/fixtures`
}));

// load specific filename from current dir
console.log(rcFile("travis", {configFileName: ".travis"}));
/*
config: { sudo: false, language: 'node_js', node_js: 'stable' }
filePath: /path/to/.travis
 */

// try to load as .json, .yml, js
console.log(rcFile("bar", {
    configFileName: `${__dirname}/test/fixtures/.barrc`,
    defaultExtension: [".json", ".yml", ".js"]
}));

// try to load as foobar, but .foobarrc is not found
console.log(rcFile("foorbar")); // => undefined

// try to load as .json, but it is not json
// throw SyntaxError
try {
    rcFile("unknown", {
        // This is not json
        configFileName: `${__dirname}/test/fixtures/.unknownrc`,
        defaultExtension: ".json"
    })
} catch (error) {
    console.log(error);
    /*
    SyntaxError: Cannot read config file: /test/fixtures/.unknownrc
    */
}

Users

• textlint

Changelog

See Releases page.

Running tests

Install devDependencies and Run npm test:

npm i -d && npm test

Contributing

Pull requests and stars are always welcome.

For bugs and feature requests, please create an issue.

1. Fork it!
2. Create your feature branch: git checkout -b my-new-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request :D

Author

• github/azu
• twitter/azu_re

License

MIT © azu

Acknowledgement

• zkochan/rcfile: Loads library configuration in all possible ways

Difference

• support multiple defaultExtension