constants-parser

constants-parser is a utility module designed to create and merge configuration objects from environment variables. This is particularly useful for managing configurations in Node.js applications.

Features

• Merges configuration objects deeply.
• Provides type safety with TypeScript.

Installation

You can install the package using npm:

npm install constants-parser

Or with yarn:

yarn add constants-parser

Usage

First, import the create function from the package:

import { create } from 'constants-parser';

Define your configuration prototype and options:

type Config = {
    apiUrl: string;
    timeout: number;
    nestedConfig: {
        featureEnabled: boolean;
    };
};

const prototype: Config = {
    apiUrl: 'https://default.api.com',
    timeout: 3000,
    nestedConfig: {
        featureEnabled: false,
    },
};

const options = {
    key: 'MY_APP_CONFIG',
    prototype: prototype,
    environment: process.env, // optional, defaults to process.env
};

Create the configuration object:

const config = create<Config>(options);

if (config) {
    console.log('Configuration:', config);
}

Set the environment variable before running your application:

export MY_APP_CONFIG='{"apiUrl": "https://custom.api.com", "timeout": 5000, "nestedConfig": {"featureEnabled": true}}'
node your-app.js

Types

Options

Represents the options for the create function.

type Options<T extends anyObj> = {
    key: string;
    prototype: T;
    environment?: NodeJS.ProcessEnv;
};

Development

Scripts

• build: Cleans the dist directory and compiles TypeScript files.
• lint: Runs ESLint on TypeScript files.
• test: Runs tests using Jest.

Building the Project

To build the project, run:

npm run build

Running Tests

To run tests, use:

npm test

Linting

To lint the project, run:

npm run lint

License

This project is licensed under the MIT License.

Author

menelreal
Email: [email protected]