feat: add user jit provisioning and preferences service

backend/libs/users/src/user-preferences.service.spec.ts

@@ -0,0 +1,60 @@
+import { UserPreferencesService } from './user-preferences.service';
+import { DEFAULT_USER_PREFERENCE } from './user.types';
+import type { UpdateUserPreferenceDto } from './user.types';
+
+describe('UserPreferencesService', () => {
+  describe('getOrDefault', () => {
+    it('returns the stored preference when one exists', async () => {
+      const stored = {
+        userId: 'u1',
+        ...DEFAULT_USER_PREFERENCE,
+        preferredPace: 'relaxed',
+      };
+      const repo = { findByUserId: jest.fn().mockResolvedValue(stored) };
+      const service = new UserPreferencesService(repo as never);
+
+      await expect(service.getOrDefault('u1')).resolves.toEqual(stored);
+    });
+
+    it('returns an in-memory default without persisting a row when none exists', async () => {
+      const repo = {
+        findByUserId: jest.fn().mockResolvedValue(undefined),
+        upsert: jest.fn(),
+      };
+      const service = new UserPreferencesService(repo as never);
+
+      const result = await service.getOrDefault('u1');
+
+      expect(result).toEqual({ userId: 'u1', ...DEFAULT_USER_PREFERENCE });
+      expect(repo.upsert).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('upsert', () => {
+    it('merges the partial dto onto the current effective preference before persisting', async () => {
+      const repo = {
+        findByUserId: jest.fn().mockResolvedValue({
+          userId: 'u1',
+          ...DEFAULT_USER_PREFERENCE,
+          preferredPace: 'relaxed',
+        }),
+        upsert: jest
+          .fn()
+          .mockImplementation((userId: string, dto: UpdateUserPreferenceDto) =>
+            Promise.resolve({ userId, ...DEFAULT_USER_PREFERENCE, ...dto }),
+          ),
+      };
+      const service = new UserPreferencesService(repo as never);
+
+      await service.upsert('u1', { childFriendlyPreferred: true });
+
+      expect(repo.upsert).toHaveBeenCalledWith(
+        'u1',
+        expect.objectContaining({
+          preferredPace: 'relaxed',
+          childFriendlyPreferred: true,
+        }),
+      );
+    });
+  });
+});