feat: Add env parser and tests

Add module for parse enviroment variables and conver it to Map.<string, string>.

src/env-parser.js

@@ -0,0 +1,28 @@
+const normalFieldName = /^[A-Z\d_\-.:]+$/i;
+const flatOnlyFieldName = /^[A-Z\d_-]+$/i;
+
+/**
+ * @param {object=} options
+ * @param {boolean=} [options.flatOnly=false]
+ * @return {Map.<string, string>}
+ */
+function envParse(options = {}) {
+ const flatOnly = options.flatOnly || false;
+
+ const { env } = global.process;
+
+ return new Map(Object.keys(env)
+ .map((key) => {
+ if (!key.match(flatOnly ? flatOnlyFieldName : normalFieldName)) {
+ throw Error(`Unsupported env field name: ${key}`);
+ }
+
+ const newKey = key.toLowerCase()
+ .replace(/([:_-])([a-z\d])/g, str => str[1].toUpperCase());
+
+ return [newKey, env[key]];
+ }));
+}
+
+export default envParse;
+module.exports = envParse;

src/env-parser.test.js

@@ -0,0 +1,54 @@
+/* eslint-env mocha */
+/* globals describe, it, before, after, beforeEach, afterEach */
+
+import { expect } from 'chai';
+import envParser from './env-parser';
+
+describe('env-parser', () => {
+ beforeEach(() => {
+ process.env = {
+ 'DATABASE.MONGODB_HOST': 'localhost',
+ 'DATABASE.MONGODB.PORT': '27316',
+ 'REDIS:HASH-ALGO': 'testName',
+ };
+ });
+
+ it('return type', () => {
+ expect(() => {
+ const result = envParser();
+
+ expect(result).to.be.an.instanceof(Map, 'Return value must be a Map');
+ }).not.to.throw();
+ });
+
+ it('keys format', () => {
+ expect(() => {
+ envParser().forEach((value, key) => {
+ expect(key).to.match(/^[A-Za-z\d.]+$/);
+ });
+ }).not.to.throw();
+ });
+
+ it('flat keys', () => {
+ process.env = {
+ DATABASE_MONGODB_HOST: 'localhost',
+ 'REDIS-HASH-ALGO': 'testName',
+ };
+
+ expect(() => {
+ envParser({ flatOnly: true }).forEach((value, key) => {
+ expect(key).to.match(/^[A-Za-z\d.]+$/);
+ });
+ }).not.to.throw();
+ });
+
+ it('flat keys - try invalid key', () => {
+ process.env = {
+ 'REDIS:HASH-ALGO': 'testName',
+ };
+
+ expect(() => {
+ envParser({ flatOnly: true });
+ }).to.throw(Error, /Unsupported env field name/);
+ });
+});