test(backend): expand helper and media coverage

Backend/tests/env.test.ts

@@ -1,6 +1,6 @@
 import { afterEach, describe, expect, test } from 'bun:test';
 
-import { getBetterAuthBaseUrl, getDeviceOnlineStaleSeconds, getFirstDefinedEnv } from '../utils/env';
+import { getBetterAuthBaseUrl, getDeviceOnlineStaleSeconds, getFirstDefinedEnv, getRequiredEnv } from '../utils/env';
 
 const ORIGINAL_ENV = { ...process.env };
 
@@ -23,6 +23,26 @@ describe('env helpers', () => {
     expect(getBetterAuthBaseUrl()).toBe('http://base-url:4000');
   });
 
+  test('getBetterAuthBaseUrl falls back to localhost with current port', () => {
+    delete process.env.BETTER_AUTH_BASE_URL;
+    delete process.env.BETTER_AUTH_URL;
+    process.env.PORT = '8088';
+
+    expect(getBetterAuthBaseUrl()).toBe('http://localhost:8088');
+  });
+
+  test('getRequiredEnv returns a trimmed value', () => {
+    process.env.EXAMPLE_SECRET = '  super-secret  ';
+
+    expect(getRequiredEnv('EXAMPLE_SECRET')).toBe('super-secret');
+  });
+
+  test('getRequiredEnv throws for missing values', () => {
+    delete process.env.MISSING_SECRET;
+
+    expect(() => getRequiredEnv('MISSING_SECRET')).toThrow('MISSING_SECRET is required');
+  });
+
   test('getDeviceOnlineStaleSeconds defaults to 30', () => {
     delete process.env.DEVICE_ONLINE_STALE_SECONDS;
     expect(getDeviceOnlineStaleSeconds()).toBe(30);