Environment Variable Validation (#122)

* Update: env validation and discord token validation

* Add: IPv4 Address Validation

* Update: version increment

src/utils/env.ts

@@ -3,16 +3,33 @@ import { config } from 'dotenv'
 
 // resolve config file
 const envFilePath = resolve(process.cwd(), '.env')
+const ipValidate: RegExp = /^((25[0-5]|(2[0-4]|1\d|[1-9]|)\d)\.?\b){4}$/
 
 // set current environment variable file
 config({ path: envFilePath })
 
-// Getter for environment variables
+/**
+ * Method to validate if environment variables found in file utils/env.ts
+ * 
+ * @param name Name of the environment variable in .env
+ * @param fallback fallback value to set if environment variable is not set (used manually in src/keys.ts)
+ * @returns environment variable value
+ */
 export function getEnvVar(name: string, fallback?: string): string {
     const value = process.env[name] ?? fallback
-    if (value == undefined)
+    if (!value)
         throw new Error(`Environment variable ${name} is not set.`)
 
+    // validate User-Generated Discord Application Tokens 
+    if (name === "CLIENT_TOKEN")
+        if (value.length < 72) throw new Error(`The "CLIENT_TOKEN" provided is not of at least length 72. 
+            This is probably an invalid token unless Discord updated their token policy. Please provide a valid token.`)
+
+    // validate IPv4 address found in environment variables
+    if (name.endsWith("_IP") || name.endsWith("_ADDRESS"))
+        if (!ipValidate.test(value))
+            throw new Error(`Environment variable ${name} does not follow IPv4 formatting.`)
+
     // return env variable
     return value
 }