feat: add envalid for better env management

src/config/env.ts

@@ -0,0 +1,78 @@
+import { config } from "dotenv";
+import { cleanEnv, num, str, bool, url, port } from "envalid";
+
+config();
+
+export const env = cleanEnv(process.env, {
+    ANIWATCH_API_PORT: port({
+        default: 4000,
+        desc: "Port number of the Aniwatch API.",
+    }),
+
+    ANIWATCH_API_WINDOW_MS: num({
+        // 60 mins if dev, else 30 mins
+        default: isDevEnv() ? 60 * 60 * 1000 : 30 * 60 * 1000,
+        desc: "Duration to track requests for rate limiting (in milliseconds).",
+        docs: "https://github.com/ghoshRitesh12/aniwatch-api/blob/main/.env.example#L9",
+    }),
+
+    ANIWATCH_API_MAX_REQS: num({
+        default: isDevEnv() ? 600 : 6,
+        desc: "Maximum number of requests in the `ANIWATCH_API_WINDOW_MS` time period.",
+    }),
+
+    ANIWATCH_API_CORS_ALLOWED_ORIGINS: str({
+        default: undefined,
+        example:
+            "https://your-production-domain.com,https://another-trusted-domain.com",
+        desc: "Allowed origins, separated by commas and no spaces in between (CSV).",
+    }),
+
+    ANIWATCH_API_VERCEL_DEPLOYMENT: bool({
+        default: false,
+        desc: "Required for distinguishing Vercel deployment from other ones; set it to true",
+    }),
+
+    ANIWATCH_API_HOSTNAME: url({
+        default: undefined,
+        example: "https://your-production-domain.com",
+        desc: "Set this to your api instance's hostname to enable rate limiting, don't have this value if you don't wish to rate limit.",
+        docs: "https://github.com/ghoshRitesh12/aniwatch-api/blob/main/.env.example#L18",
+    }),
+
+    ANIWATCH_API_REDIS_CONN_URL: url({
+        default: undefined,
+        example:
+            "rediss://default:your-secure-password@your-redis-instance-name.provider.com:6379",
+        desc: "This env is optional by default and can be set to utilize Redis caching functionality. It has to be a valid connection URL.",
+    }),
+
+    ANIWATCH_API_S_MAXAGE: num({
+        default: 60,
+        desc: "Specifies the maximum amount of time (in seconds) a resource is considered fresh when served by a CDN cache.",
+    }),
+
+    ANIWATCH_API_STALE_WHILE_REVALIDATE: num({
+        default: 30,
+        desc: "Specifies the amount of time (in seconds) a resource is served stale while a new one is fetched.",
+    }),
+
+    NODE_ENV: str({
+        default: "development",
+        choices: ["development", "production", "test", "staging"],
+        desc: "The environment in which the application is running.",
+        docs: "https://nodejs.org/en/learn/getting-started/nodejs-the-difference-between-development-and-production",
+    }),
+});
+
+function isDevEnv(): boolean {
+    return (
+        !process.env.NODE_ENV ||
+        process.env.NODE_ENV === "development" ||
+        process.env.NODE_ENV === "test"
+    );
+}
+
+export function isEnvUndefined(envVar?: string): boolean {
+    return typeof envVar === "undefined" || envVar === "undefined";
+}