results from npm create t3-app@latest

src/env.mjs

@@ -0,0 +1,94 @@
+import { z } from "zod";
+
+/**
+ * Specify your server-side environment variables schema here. This way you can ensure the app isn't
+ * built with invalid env vars.
+ */
+const server = z.object({
+  DATABASE_URL: z.string().url(),
+  NODE_ENV: z.enum(["development", "test", "production"]),
+  NEXTAUTH_SECRET:
+    process.env.NODE_ENV === "production"
+      ? z.string().min(1)
+      : z.string().min(1).optional(),
+  NEXTAUTH_URL: z.preprocess(
+    // This makes Vercel deployments not fail if you don't set NEXTAUTH_URL
+    // Since NextAuth.js automatically uses the VERCEL_URL if present.
+    (str) => process.env.VERCEL_URL ?? str,
+    // VERCEL_URL doesn't include `https` so it cant be validated as a URL
+    process.env.VERCEL ? z.string().min(1) : z.string().url(),
+  ),
+  // Add `.min(1) on ID and SECRET if you want to make sure they're not empty
+  DISCORD_CLIENT_ID: z.string(),
+  DISCORD_CLIENT_SECRET: z.string(),
+});
+
+/**
+ * Specify your client-side environment variables schema here. This way you can ensure the app isn't
+ * built with invalid env vars. To expose them to the client, prefix them with `NEXT_PUBLIC_`.
+ */
+const client = z.object({
+  // NEXT_PUBLIC_CLIENTVAR: z.string().min(1),
+});
+
+/**
+ * You can't destruct `process.env` as a regular object in the Next.js edge runtimes (e.g.
+ * middlewares) or client-side so we need to destruct manually.
+ *
+ * @type {Record<keyof z.infer<typeof server> | keyof z.infer<typeof client>, string | undefined>}
+ */
+const processEnv = {
+  DATABASE_URL: process.env.DATABASE_URL,
+  NODE_ENV: process.env.NODE_ENV,
+  NEXTAUTH_SECRET: process.env.NEXTAUTH_SECRET,
+  NEXTAUTH_URL: process.env.NEXTAUTH_URL,
+  DISCORD_CLIENT_ID: process.env.DISCORD_CLIENT_ID,
+  DISCORD_CLIENT_SECRET: process.env.DISCORD_CLIENT_SECRET,
+  // NEXT_PUBLIC_CLIENTVAR: process.env.NEXT_PUBLIC_CLIENTVAR,
+};
+
+// Don't touch the part below
+// --------------------------
+
+const merged = server.merge(client);
+
+/** @typedef {z.input<typeof merged>} MergedInput */
+/** @typedef {z.infer<typeof merged>} MergedOutput */
+/** @typedef {z.SafeParseReturnType<MergedInput, MergedOutput>} MergedSafeParseReturn */
+
+let env = /** @type {MergedOutput} */ (process.env);
+
+if (!!process.env.SKIP_ENV_VALIDATION == false) {
+  const isServer = typeof window === "undefined";
+
+  const parsed = /** @type {MergedSafeParseReturn} */ (
+    isServer
+      ? merged.safeParse(processEnv) // on server we can validate all env vars
+      : client.safeParse(processEnv) // on client we can only validate the ones that are exposed
+  );
+
+  if (parsed.success === false) {
+    console.error(
+      "❌ Invalid environment variables:",
+      parsed.error.flatten().fieldErrors,
+    );
+    throw new Error("Invalid environment variables");
+  }
+
+  env = new Proxy(parsed.data, {
+    get(target, prop) {
+      if (typeof prop !== "string") return undefined;
+      // Throw a descriptive error if a server-side env var is accessed on the client
+      // Otherwise it would just be returning `undefined` and be annoying to debug
+      if (!isServer && !prop.startsWith("NEXT_PUBLIC_"))
+        throw new Error(
+          process.env.NODE_ENV === "production"
+            ? "❌ Attempted to access a server-side environment variable on the client"
+            : `❌ Attempted to access server-side environment variable '${prop}' on the client`,
+        );
+      return target[/** @type {keyof typeof target} */ (prop)];
+    },
+  });
+}
+
+export { env };