feat(api): implement /users/me/preferences endpoint

Implements GET/PATCH/PUT /users/me/preferences. Fixes profile page 'Preferences unavailable' error by correcting the /api prefix in frontend calls and adding PATCH handler to controller.

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/api/src/users/preferences.controller.spec.ts

@@ -0,0 +1,112 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import { UnauthorizedException } from "@nestjs/common";
+import { PreferencesController } from "./preferences.controller";
+import { PreferencesService } from "./preferences.service";
+import type { UpdatePreferencesDto, PreferencesResponseDto } from "./dto";
+import type { AuthenticatedRequest } from "../common/types/user.types";
+
+describe("PreferencesController", () => {
+  let controller: PreferencesController;
+  let service: PreferencesService;
+
+  const mockPreferencesService = {
+    getPreferences: vi.fn(),
+    updatePreferences: vi.fn(),
+  };
+
+  const mockUserId = "user-uuid-123";
+
+  const mockPreferencesResponse: PreferencesResponseDto = {
+    id: "pref-uuid-456",
+    userId: mockUserId,
+    theme: "system",
+    locale: "en",
+    timezone: null,
+    settings: {},
+    updatedAt: new Date("2026-01-01T00:00:00Z"),
+  };
+
+  function makeRequest(userId?: string): AuthenticatedRequest {
+    return {
+      user: userId ? { id: userId } : undefined,
+    } as unknown as AuthenticatedRequest;
+  }
+
+  beforeEach(() => {
+    service = mockPreferencesService as unknown as PreferencesService;
+    controller = new PreferencesController(service);
+    vi.clearAllMocks();
+  });
+
+  describe("GET /api/users/me/preferences", () => {
+    it("should return preferences for authenticated user", async () => {
+      mockPreferencesService.getPreferences.mockResolvedValue(mockPreferencesResponse);
+
+      const result = await controller.getPreferences(makeRequest(mockUserId));
+
+      expect(result).toEqual(mockPreferencesResponse);
+      expect(mockPreferencesService.getPreferences).toHaveBeenCalledWith(mockUserId);
+    });
+
+    it("should throw UnauthorizedException when user is not authenticated", async () => {
+      await expect(controller.getPreferences(makeRequest())).rejects.toThrow(UnauthorizedException);
+      expect(mockPreferencesService.getPreferences).not.toHaveBeenCalled();
+    });
+  });
+
+  describe("PUT /api/users/me/preferences", () => {
+    const updateDto: UpdatePreferencesDto = {
+      theme: "dark",
+      locale: "fr",
+      timezone: "Europe/Paris",
+    };
+
+    it("should update and return preferences for authenticated user", async () => {
+      const updatedResponse: PreferencesResponseDto = {
+        ...mockPreferencesResponse,
+        theme: "dark",
+        locale: "fr",
+        timezone: "Europe/Paris",
+      };
+      mockPreferencesService.updatePreferences.mockResolvedValue(updatedResponse);
+
+      const result = await controller.updatePreferences(updateDto, makeRequest(mockUserId));
+
+      expect(result).toEqual(updatedResponse);
+      expect(mockPreferencesService.updatePreferences).toHaveBeenCalledWith(mockUserId, updateDto);
+    });
+
+    it("should throw UnauthorizedException when user is not authenticated", async () => {
+      await expect(controller.updatePreferences(updateDto, makeRequest())).rejects.toThrow(
+        UnauthorizedException
+      );
+      expect(mockPreferencesService.updatePreferences).not.toHaveBeenCalled();
+    });
+  });
+
+  describe("PATCH /api/users/me/preferences", () => {
+    const patchDto: UpdatePreferencesDto = {
+      theme: "light",
+    };
+
+    it("should partially update and return preferences for authenticated user", async () => {
+      const patchedResponse: PreferencesResponseDto = {
+        ...mockPreferencesResponse,
+        theme: "light",
+      };
+      mockPreferencesService.updatePreferences.mockResolvedValue(patchedResponse);
+
+      const result = await controller.patchPreferences(patchDto, makeRequest(mockUserId));
+
+      expect(result).toEqual(patchedResponse);
+      expect(mockPreferencesService.updatePreferences).toHaveBeenCalledWith(mockUserId, patchDto);
+    });
+
+    it("should throw UnauthorizedException when user is not authenticated", async () => {
+      await expect(controller.patchPreferences(patchDto, makeRequest())).rejects.toThrow(
+        UnauthorizedException
+      );
+      expect(mockPreferencesService.updatePreferences).not.toHaveBeenCalled();
+    });
+  });
+});

apps/api/src/users/preferences.controller.ts

@@ -2,6 +2,7 @@ import {
   Controller,
   Get,
   Put,
+  Patch,
   Body,
   UseGuards,
   Request,
@@ -38,7 +39,7 @@ export class PreferencesController {
 
   /**
    * PUT /api/users/me/preferences
-   * Update current user's preferences
+   * Full replace of current user's preferences
    */
   @Put()
   async updatePreferences(
@@ -53,4 +54,22 @@ export class PreferencesController {
 
     return this.preferencesService.updatePreferences(userId, updatePreferencesDto);
   }
+
+  /**
+   * PATCH /api/users/me/preferences
+   * Partial update of current user's preferences
+   */
+  @Patch()
+  async patchPreferences(
+    @Body() updatePreferencesDto: UpdatePreferencesDto,
+    @Request() req: AuthenticatedRequest
+  ) {
+    const userId = req.user?.id;
+
+    if (!userId) {
+      throw new UnauthorizedException("Authentication required");
+    }
+
+    return this.preferencesService.updatePreferences(userId, updatePreferencesDto);
+  }
 }

apps/api/src/users/preferences.service.spec.ts

@@ -0,0 +1,141 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import { PreferencesService } from "./preferences.service";
+import type { PrismaService } from "../prisma/prisma.service";
+import type { UpdatePreferencesDto } from "./dto";
+
+describe("PreferencesService", () => {
+  let service: PreferencesService;
+
+  const mockPrisma = {
+    userPreference: {
+      findUnique: vi.fn(),
+      create: vi.fn(),
+      update: vi.fn(),
+    },
+  };
+
+  const mockUserId = "user-uuid-123";
+
+  const mockDbPreference = {
+    id: "pref-uuid-456",
+    userId: mockUserId,
+    theme: "system",
+    locale: "en",
+    timezone: null,
+    settings: {},
+    updatedAt: new Date("2026-01-01T00:00:00Z"),
+  };
+
+  beforeEach(() => {
+    service = new PreferencesService(mockPrisma as unknown as PrismaService);
+    vi.clearAllMocks();
+  });
+
+  describe("getPreferences", () => {
+    it("should return existing preferences", async () => {
+      mockPrisma.userPreference.findUnique.mockResolvedValue(mockDbPreference);
+
+      const result = await service.getPreferences(mockUserId);
+
+      expect(result).toMatchObject({
+        id: mockDbPreference.id,
+        userId: mockUserId,
+        theme: "system",
+        locale: "en",
+        timezone: null,
+        settings: {},
+      });
+      expect(mockPrisma.userPreference.findUnique).toHaveBeenCalledWith({
+        where: { userId: mockUserId },
+      });
+      expect(mockPrisma.userPreference.create).not.toHaveBeenCalled();
+    });
+
+    it("should create default preferences when none exist", async () => {
+      mockPrisma.userPreference.findUnique.mockResolvedValue(null);
+      mockPrisma.userPreference.create.mockResolvedValue(mockDbPreference);
+
+      const result = await service.getPreferences(mockUserId);
+
+      expect(result).toMatchObject({
+        id: mockDbPreference.id,
+        userId: mockUserId,
+        theme: "system",
+        locale: "en",
+      });
+      expect(mockPrisma.userPreference.create).toHaveBeenCalledWith({
+        data: expect.objectContaining({
+          userId: mockUserId,
+          theme: "system",
+          locale: "en",
+        }),
+      });
+    });
+  });
+
+  describe("updatePreferences", () => {
+    it("should update existing preferences", async () => {
+      const updateDto: UpdatePreferencesDto = { theme: "dark", locale: "fr" };
+      const updatedPreference = { ...mockDbPreference, theme: "dark", locale: "fr" };
+
+      mockPrisma.userPreference.findUnique.mockResolvedValue(mockDbPreference);
+      mockPrisma.userPreference.update.mockResolvedValue(updatedPreference);
+
+      const result = await service.updatePreferences(mockUserId, updateDto);
+
+      expect(result).toMatchObject({ theme: "dark", locale: "fr" });
+      expect(mockPrisma.userPreference.update).toHaveBeenCalledWith({
+        where: { userId: mockUserId },
+        data: expect.objectContaining({ theme: "dark", locale: "fr" }),
+      });
+      expect(mockPrisma.userPreference.create).not.toHaveBeenCalled();
+    });
+
+    it("should create preferences when updating non-existent record", async () => {
+      const updateDto: UpdatePreferencesDto = { theme: "light" };
+      const createdPreference = { ...mockDbPreference, theme: "light" };
+
+      mockPrisma.userPreference.findUnique.mockResolvedValue(null);
+      mockPrisma.userPreference.create.mockResolvedValue(createdPreference);
+
+      const result = await service.updatePreferences(mockUserId, updateDto);
+
+      expect(result).toMatchObject({ theme: "light" });
+      expect(mockPrisma.userPreference.create).toHaveBeenCalledWith({
+        data: expect.objectContaining({
+          userId: mockUserId,
+          theme: "light",
+        }),
+      });
+      expect(mockPrisma.userPreference.update).not.toHaveBeenCalled();
+    });
+
+    it("should handle timezone update", async () => {
+      const updateDto: UpdatePreferencesDto = { timezone: "America/New_York" };
+      const updatedPreference = { ...mockDbPreference, timezone: "America/New_York" };
+
+      mockPrisma.userPreference.findUnique.mockResolvedValue(mockDbPreference);
+      mockPrisma.userPreference.update.mockResolvedValue(updatedPreference);
+
+      const result = await service.updatePreferences(mockUserId, updateDto);
+
+      expect(result.timezone).toBe("America/New_York");
+      expect(mockPrisma.userPreference.update).toHaveBeenCalledWith({
+        where: { userId: mockUserId },
+        data: expect.objectContaining({ timezone: "America/New_York" }),
+      });
+    });
+
+    it("should handle settings update", async () => {
+      const updateDto: UpdatePreferencesDto = { settings: { notifications: true } };
+      const updatedPreference = { ...mockDbPreference, settings: { notifications: true } };
+
+      mockPrisma.userPreference.findUnique.mockResolvedValue(mockDbPreference);
+      mockPrisma.userPreference.update.mockResolvedValue(updatedPreference);
+
+      const result = await service.updatePreferences(mockUserId, updateDto);
+
+      expect(result.settings).toEqual({ notifications: true });
+    });
+  });
+});