Code Samples

Environment variables

To set up environment variables from .env files in project root.

Synchronous way

import { getConfigFilesSync } from "@constantiner/resolve-node-configs-hierarchy";
import dotenv from "dotenv";
import dotenvExpand from "dotenv-expand";

const dotenvFiles = getConfigFilesSync(".env");
dotenvFiles.forEach(file => {
    dotenvExpand(
        dotenv.config({
            path: file
        })
    );
});

Asynchronous way

import { getConfigFiles } from "@constantiner/resolve-node-configs-hierarchy";
import dotenv from "dotenv";
import dotenvExpand from "dotenv-expand";

getConfigFiles(".env").then(dotenvFiles => {
    dotenvFiles.forEach(file => {
        dotenvExpand(
            dotenv.config({
                path: file
            })
        );
    });
});

Reading configuration from JSON file

import { getConfigFileSync } from "@constantiner/resolve-node-configs-hierarchy";

const settingsFileName = getConfigFileSync("./settings.json");

const settings = require(settingsFileName);

console.log(settings.apiKey);

Environment related JavaScript

For example, we need some empty implementation of Email sender in development environment, some stub implementation for test environment and some real Email sending functionality for production.

So we have production implementation in <project_root>/email/emailSender.js:

const sendEmail = (to, subject, body) => {
    // Some real implementation here
    return sentStatus;
}

export { sendEmail };

Then some empty implementation in <project_root>/email/emailSender.development.js:

const sendEmail = (to, subject, body) => {
    // Do nothing
    return true;
}

export { sendEmail };

And something similar in <project_root>/email/emailSender.test.js.

Then in our real code we can use it the following way:

import { getConfigFileSync } from "@constantiner/resolve-node-configs-hierarchy";

const emailSenderFileName = getConfigFileSync("./email/emailSender.js");

const sendEmail = require(emailSenderFileName).sendEmail;

const emailSent = sendEmail("hello@example.com", "Test message", "Hello there!");
console.log(`Email sent status is ${emailSent}`);

You may implement the same with dynamic imports.