fix(mobile): reject unknown app variants

apps/mobile/app.config.test.ts

@@ -0,0 +1,33 @@
+import { afterEach, expect, it, vi } from "vite-plus/test";
+
+// Keep config parsing independent of local env files and build credentials.
+vi.mock("../../scripts/lib/public-config.ts", () => ({
+  loadRepoEnv: () => ({ APP_VARIANT: process.env.APP_VARIANT }),
+}));
+
+afterEach(() => {
+  vi.unstubAllEnvs();
+});
+
+async function loadConfig(variant: string | undefined) {
+  vi.resetModules();
+  vi.stubEnv("APP_VARIANT", variant);
+  return (await import("./app.config.ts")).default;
+}
+
+it.each(["prod", ""])("rejects APP_VARIANT=%j before selecting production IDs", async (value) => {
+  await expect(loadConfig(value)).rejects.toThrow(
+    "APP_VARIANT must be development, preview, or production.",
+  );
+});
+
+it.each([
+  [undefined, "com.t3tools.t3code"],
+  ["development", "com.t3tools.t3code.dev"],
+  ["preview", "com.t3tools.t3code.preview"],
+  ["production", "com.t3tools.t3code"],
+])("keeps the iOS and Android identifiers for APP_VARIANT=%j", async (value, identifier) => {
+  const config = await loadConfig(value);
+  expect(config.ios?.bundleIdentifier).toBe(identifier);
+  expect(config.android?.package).toBe(identifier);
+});

apps/mobile/app.config.ts

@@ -102,8 +102,10 @@ function resolveAppVariant(value: string | undefined): AppVariant {
     case "preview":
     case "production":
       return value;
-    default:
+    case undefined:
       return "production";
+    default:
+      throw new Error("APP_VARIANT must be development, preview, or production.");
   }
 }