refactor: env validation typescript and common package (#1912)

packages/db/env.ts

@@ -0,0 +1,61 @@
+import { createEnv } from "@t3-oss/env-nextjs";
+import { z } from "zod";
+
+import { shouldSkipEnvValidation } from "@homarr/common/env-validation";
+
+const drivers = {
+  betterSqlite3: "better-sqlite3",
+  mysql2: "mysql2",
+} as const;
+
+const isDriver = (driver: (typeof drivers)[keyof typeof drivers]) => process.env.DB_DRIVER === driver;
+const isUsingDbHost = Boolean(process.env.DB_HOST);
+const onlyAllowUrl = isDriver(drivers.betterSqlite3);
+const urlRequired = onlyAllowUrl || !isUsingDbHost;
+const hostRequired = isUsingDbHost && !onlyAllowUrl;
+
+export const env = createEnv({
+  /**
+   * Specify your server-side environment variables schema here. This way you can ensure the app isn't
+   * built with invalid env vars.
+   */
+  server: {
+    DB_DRIVER: z
+      .union([z.literal(drivers.betterSqlite3), z.literal(drivers.mysql2)], {
+        message: `Invalid database driver, supported are ${Object.keys(drivers).join(", ")}`,
+      })
+      .default(drivers.betterSqlite3),
+    ...(urlRequired
+      ? {
+          DB_URL: z.string(),
+        }
+      : {}),
+    ...(hostRequired
+      ? {
+          DB_HOST: z.string(),
+          DB_PORT: z
+            .string()
+            .regex(/\d+/)
+            .transform(Number)
+            .refine((number) => number >= 1)
+            .default("3306"),
+          DB_USER: z.string(),
+          DB_PASSWORD: z.string(),
+          DB_NAME: z.string(),
+        }
+      : {}),
+  },
+  /**
+   * Destructure all variables from `process.env` to make sure they aren't tree-shaken away.
+   */
+  runtimeEnv: {
+    DB_DRIVER: process.env.DB_DRIVER,
+    DB_URL: process.env.DB_URL,
+    DB_HOST: process.env.DB_HOST,
+    DB_USER: process.env.DB_USER,
+    DB_PASSWORD: process.env.DB_PASSWORD,
+    DB_NAME: process.env.DB_NAME,
+    DB_PORT: process.env.DB_PORT,
+  },
+  skipValidation: shouldSkipEnvValidation(),
+});