From f61769e7fcf2ad5ac916deddcf356d467b7af757 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Lenon?= <lenonsec7@gmail.com>
Date: Thu, 18 Nov 2021 11:40:57 -0300
Subject: [PATCH] feat(env): add support to template string on env function

feat #3
---
 README.md            |  9 ++++++++-
 package.json         |  2 +-
 src/Env.ts           | 17 ++++++++++++++++-
 tests/env.spec.ts    |  8 ++++++++
 tests/global.spec.ts | 13 +++++++++++++
 5 files changed, 46 insertions(+), 3 deletions(-)
 create mode 100644 tests/global.spec.ts

diff --git a/README.md b/README.md
index 4dfc163..98c7863 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 > Very simple Env get function for NodeJS
 
 [![GitHub followers](https://img.shields.io/github/followers/jlenon7.svg?style=social&label=Follow&maxAge=2592000)](https://github.com/jlenon7?tab=followers)
-[![GitHub stars](https://img.shields.io/github/stars/secjs/config.svg?style=social&label=Star&maxAge=2592000)](https://github.com/secjs/env/stargazers/)
+[![GitHub stars](https://img.shields.io/github/stars/secjs/env.svg?style=social&label=Star&maxAge=2592000)](https://github.com/secjs/env/stargazers/)
 
 <p>
     <a href="https://www.buymeacoffee.com/secjs" target="_blank"><img src="https://www.buymeacoffee.com/assets/img/custom_images/orange_img.png" alt="Buy Me A Coffee" style="height: 41px !important;width: 174px !important;box-shadow: 0px 3px 2px 0px rgba(190, 190, 190, 0.5) !important;-webkit-box-shadow: 0px 3px 2px 0px rgba(190, 190, 190, 0.5) !important;" ></a>
@@ -65,14 +65,21 @@ Env('DB_DATABASE', 'my-database')
 import { Env } from '@secjs/env'
 
 // Simulating .env file
+HOST='127.0.0.1'
+PORT=3333
 DB_PORT=5432
 DB_DEBUG=false
 DB_DATABASE='database'
+APP_URL='http://${HOST}:${PORT}'
 
 // The response value will be the value of DB_DATABASE variable or my-database by default
 const db = Env('DB_DATABASE', 'my-database')
 console.log(db) // 'database'
 
+// Template string support
+const appUrl = Env('APP_URL', 'http://localhost:3000')
+console.log(appUrl) // 'http://127.0.0.1:3333'
+
 const dbPort = Env('DB_PORT', '5432')
 console.log(dbPort) // '5432'
 
diff --git a/package.json b/package.json
index 8ffd6a4..2988a7b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@secjs/env",
-  "version": "1.2.4",
+  "version": "1.2.5",
   "license": "MIT",
   "author": "João Lenon",
   "repository": "https://github.com/SecJS/Env.git",
diff --git a/src/Env.ts b/src/Env.ts
index c526182..788580d 100644
--- a/src/Env.ts
+++ b/src/Env.ts
@@ -19,7 +19,7 @@ export function Env(
   env: string | IEnv,
   defaultValue: string | number | boolean,
 ): string | number | boolean | any {
-  const environment = process.env[`${typeof env === 'string' ? env : env.name}`]
+  let environment = process.env[`${typeof env === 'string' ? env : env.name}`]
 
   if (!environment) {
     logger.debug(`Variable ${env} not found`)
@@ -38,5 +38,20 @@ export function Env(
     return defaultValue
   }
 
+  const matches = environment.match(/\${([^}]+)}/g)
+
+  if (matches) {
+    for (let match of matches) {
+      const key = match.replace(/[!${}]+/g, '')
+
+      match = match.replace('$', '\\$')
+
+      environment = environment.replace(
+        new RegExp(match, 'g'),
+        process.env[key] || null,
+      )
+    }
+  }
+
   return environment
 }
diff --git a/tests/env.spec.ts b/tests/env.spec.ts
index 6f293be..76d342f 100644
--- a/tests/env.spec.ts
+++ b/tests/env.spec.ts
@@ -5,6 +5,7 @@ describe('\n Env 🔁', () => {
   let DB_PASSWORD = ''
 
   beforeAll(() => {
+    process.env.HOST = '127.0.0.1'
     process.env.PORT = '3333'
     process.env.DB_DEBUG = 'false'
     process.env.DB_USERNAME = 'user'
@@ -31,6 +32,13 @@ describe('\n Env 🔁', () => {
     expect(DB_PORT).toBe(portDefaultValue)
   })
 
+  it('should replace template strings on environment values', () => {
+    // eslint-disable-next-line no-template-curly-in-string
+    process.env.APP_URL = 'http://${HOST}:${PORT}'
+
+    expect(Env('APP_URL', '')).toBe('http://127.0.0.1:3333')
+  })
+
   it('should get an environment variable type using a object with env name and type to Env function', () => {
     const PORT = Env({ name: 'PORT', type: 'number' }, '')
     const DB_DEBUG = Env({ name: 'DB_DEBUG', type: 'boolean' }, '')
diff --git a/tests/global.spec.ts b/tests/global.spec.ts
new file mode 100644
index 0000000..7419a66
--- /dev/null
+++ b/tests/global.spec.ts
@@ -0,0 +1,13 @@
+import '../src/utils/global'
+
+describe('\n Global 🔁', () => {
+  beforeAll(() => {
+    process.env.DB_USERNAME = 'user'
+    process.env.DB_PASSWORD = 'pass'
+  })
+
+  it('should get an environment variable from name using global Env', () => {
+    expect(Env('DB_USERNAME', '')).toBe('user')
+    expect(Env('DB_PASSWORD', '')).toBe('pass')
+  })
+})