fix(#414): extract trustedOrigins to getTrustedOrigins() with env vars

Replace hardcoded production URLs with environment-driven config.
Reads NEXT_PUBLIC_APP_URL, NEXT_PUBLIC_API_URL, TRUSTED_ORIGINS.
Localhost fallbacks only in development mode.

Refs #414

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/auth/auth.config.spec.ts

@@ -18,12 +18,7 @@ vi.mock("better-auth/adapters/prisma", () => ({
   prismaAdapter: (...args: unknown[]) => mockPrismaAdapter(...args),
 }));
 
-import {
-  isOidcEnabled,
-  validateOidcConfig,
-  createAuth,
-  getTrustedOrigins,
-} from "./auth.config";
+import { isOidcEnabled, validateOidcConfig, createAuth, getTrustedOrigins } from "./auth.config";
 
 describe("auth.config", () => {
   // Store original env vars to restore after each test
@@ -290,6 +285,127 @@ describe("auth.config", () => {
     });
   });
 
+  describe("getTrustedOrigins", () => {
+    it("should return localhost URLs when NODE_ENV is not production", () => {
+      process.env.NODE_ENV = "development";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).toContain("http://localhost:3000");
+      expect(origins).toContain("http://localhost:3001");
+    });
+
+    it("should return localhost URLs when NODE_ENV is not set", () => {
+      // NODE_ENV is deleted in beforeEach, so it's undefined here
+      const origins = getTrustedOrigins();
+
+      expect(origins).toContain("http://localhost:3000");
+      expect(origins).toContain("http://localhost:3001");
+    });
+
+    it("should exclude localhost URLs in production", () => {
+      process.env.NODE_ENV = "production";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).not.toContain("http://localhost:3000");
+      expect(origins).not.toContain("http://localhost:3001");
+    });
+
+    it("should parse TRUSTED_ORIGINS comma-separated values", () => {
+      process.env.TRUSTED_ORIGINS =
+        "https://app.mosaicstack.dev,https://api.mosaicstack.dev";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).toContain("https://app.mosaicstack.dev");
+      expect(origins).toContain("https://api.mosaicstack.dev");
+    });
+
+    it("should trim whitespace from TRUSTED_ORIGINS entries", () => {
+      process.env.TRUSTED_ORIGINS =
+        " https://app.mosaicstack.dev , https://api.mosaicstack.dev ";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).toContain("https://app.mosaicstack.dev");
+      expect(origins).toContain("https://api.mosaicstack.dev");
+    });
+
+    it("should filter out empty strings from TRUSTED_ORIGINS", () => {
+      process.env.TRUSTED_ORIGINS = "https://app.mosaicstack.dev,,, ,";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).toContain("https://app.mosaicstack.dev");
+      // No empty strings in the result
+      origins.forEach((o) => expect(o).not.toBe(""));
+    });
+
+    it("should include NEXT_PUBLIC_APP_URL", () => {
+      process.env.NEXT_PUBLIC_APP_URL = "https://my-app.example.com";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).toContain("https://my-app.example.com");
+    });
+
+    it("should include NEXT_PUBLIC_API_URL", () => {
+      process.env.NEXT_PUBLIC_API_URL = "https://my-api.example.com";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).toContain("https://my-api.example.com");
+    });
+
+    it("should deduplicate origins", () => {
+      process.env.NEXT_PUBLIC_APP_URL = "http://localhost:3000";
+      process.env.TRUSTED_ORIGINS = "http://localhost:3000,http://localhost:3001";
+      // NODE_ENV not set, so localhost fallbacks are also added
+
+      const origins = getTrustedOrigins();
+
+      const countLocalhost3000 = origins.filter((o) => o === "http://localhost:3000").length;
+      const countLocalhost3001 = origins.filter((o) => o === "http://localhost:3001").length;
+      expect(countLocalhost3000).toBe(1);
+      expect(countLocalhost3001).toBe(1);
+    });
+
+    it("should handle all env vars missing gracefully", () => {
+      // All env vars deleted in beforeEach; NODE_ENV is also deleted (not production)
+      const origins = getTrustedOrigins();
+
+      // Should still return localhost fallbacks since not in production
+      expect(origins).toContain("http://localhost:3000");
+      expect(origins).toContain("http://localhost:3001");
+      expect(origins).toHaveLength(2);
+    });
+
+    it("should return empty array when all env vars missing in production", () => {
+      process.env.NODE_ENV = "production";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).toHaveLength(0);
+    });
+
+    it("should combine all sources correctly", () => {
+      process.env.NEXT_PUBLIC_APP_URL = "https://app.mosaicstack.dev";
+      process.env.NEXT_PUBLIC_API_URL = "https://api.mosaicstack.dev";
+      process.env.TRUSTED_ORIGINS = "https://extra.example.com";
+      process.env.NODE_ENV = "development";
+
+      const origins = getTrustedOrigins();
+
+      expect(origins).toContain("https://app.mosaicstack.dev");
+      expect(origins).toContain("https://api.mosaicstack.dev");
+      expect(origins).toContain("https://extra.example.com");
+      expect(origins).toContain("http://localhost:3000");
+      expect(origins).toContain("http://localhost:3001");
+      expect(origins).toHaveLength(5);
+    });
+  });
+
   describe("createAuth - session and cookie configuration", () => {
     beforeEach(() => {
       mockGenericOAuth.mockClear();