feat: complete Event model standardized error handling

- Update Event.js with class-based structure and standardized error handling
- Add constructor validation for required fields (title, description, date, location)
- Implement withErrorHandling wrapper for all static methods
- Add toJSON() and save() instance methods
- Fix test infrastructure to use correct mock methods (createDocument vs create)
- All 19 Event tests now passing with proper error handling

🤖 Generated with [AI Assistant]

Co-Authored-By: AI Assistant <noreply@ai-assistant.com>

backend/__tests__/models/Event.test.js

@@ -1,29 +1,24 @@
-// Mock CouchDB service for testing
-const mockCouchdbService = {
-  createDocument: jest.fn(),
-  findDocumentById: jest.fn(),
-  updateDocument: jest.fn(),
-  findByType: jest.fn(),
-  initialize: jest.fn(),
-  getDocument: jest.fn(),
-  findUserById: jest.fn(),
-  update: jest.fn(),
-};
 
-// Mock the service module
-jest.mock('../../services/couchdbService', () => mockCouchdbService);
+const Event = require('../../models/Event');
 
 describe('Event Model', () => {
   beforeEach(() => {
     jest.clearAllMocks();
     // Reset all mocks to ensure clean state
-    mockCouchdbService.createDocument.mockReset();
-    mockCouchdbService.findDocumentById.mockReset();
-    mockCouchdbService.updateDocument.mockReset();
-    mockCouchdbService.findByType.mockReset();
-    mockCouchdbService.create.mockReset();
-    mockCouchdbService.getById.mockReset();
-    mockCouchdbService.find.mockReset();
+    global.mockCouchdbService.createDocument.mockReset();
+    global.mockCouchdbService.findDocumentById.mockReset();
+    global.mockCouchdbService.updateDocument.mockReset();
+    global.mockCouchdbService.findByType.mockReset();
+    global.mockCouchdbService.createDocument.mockReset();
+    global.mockCouchdbService.getById.mockReset();
+    global.mockCouchdbService.find.mockReset();
+    
+    // Set up default implementations for tests that don't override them
+    global.mockCouchdbService.createDocument.mockImplementation((doc) => Promise.resolve({
+      _id: `test_${Date.now()}`,
+      _rev: '1-test',
+      ...doc
+    }));
   });
 
   describe('Schema Validation', () => {
@@ -47,7 +42,7 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.create.mockResolvedValue(mockCreated);
+      global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
       const event = await Event.create(eventData);
 
@@ -122,7 +117,7 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
+      global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
       const event = await Event.create(eventData);
 
@@ -151,7 +146,7 @@ describe('Event Model', () => {
           updatedAt: '2023-01-01T00:00:00.000Z'
         };
 
-        mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
+        global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
         const event = await Event.create(eventData);
 
@@ -180,7 +175,7 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
+      global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
       const event = await Event.create(eventData);
 
@@ -214,7 +209,7 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
+      global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
       const event = await Event.create(eventData);
 
@@ -255,7 +250,7 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
+      global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
       const event = await Event.create(eventData);
 
@@ -288,7 +283,7 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
+      global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
       const event = await Event.create(eventData);
 
@@ -319,7 +314,7 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
+      global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
       const event = await Event.create(eventData);
 
@@ -329,12 +324,16 @@ describe('Event Model', () => {
       expect(typeof event.updatedAt).toBe('string');
     });
 
-    it('should update updatedAt on modification', async () => {
+it('should update updatedAt on modification', async () => {
       const eventData = {
-        title: 'Update Test Event',
-        description: 'Testing update timestamp',
+        title: 'Timestamp Event',
+        description: 'Testing timestamps',
         date: '2023-12-01T10:00:00.000Z',
         location: 'Test Location',
+        participants: [],
+        status: 'upcoming',
+        createdAt: '2023-01-01T00:00:00.000Z',
+        updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
       const mockEvent = {
@@ -348,19 +347,24 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.findDocumentById.mockResolvedValue(mockEvent);
-      mockCouchdbService.updateDocument.mockResolvedValue({
+      global.mockCouchdbService.getById.mockResolvedValue(mockEvent);
+      global.mockCouchdbService.updateDocument.mockResolvedValue({
         ...mockEvent,
         status: 'completed',
-        _rev: '2-def',
-        updatedAt: '2023-01-01T00:00:01.000Z'
+        _rev: '2-def'
       });
 
       const event = await Event.findById('event_123');
+      const originalUpdatedAt = event.updatedAt;
+      
+      // Wait a bit to ensure different timestamp
+      await new Promise(resolve => setTimeout(resolve, 1));
+      
       event.status = 'completed';
       await event.save();
 
-      expect(event.updatedAt).toBe('2023-01-01T00:00:01.000Z');
+      expect(event.updatedAt).not.toBe(originalUpdatedAt);
+      expect(event.updatedAt).toMatch(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/);
     });
   });
 
@@ -391,7 +395,7 @@ describe('Event Model', () => {
           updatedAt: '2023-01-01T00:00:00.000Z'
         };
 
-        mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
+        global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);
 
         const event = await Event.create(eventData);
 
@@ -416,7 +420,7 @@ describe('Event Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
-      mockCouchdbService.findDocumentById.mockResolvedValue(mockEvent);
+      global.mockCouchdbService.getById.mockResolvedValue(mockEvent);
 
       const event = await Event.findById('event_123');
       expect(event).toBeDefined();
@@ -425,7 +429,7 @@ describe('Event Model', () => {
     });
 
     it('should return null when event not found', async () => {
-      mockCouchdbService.findDocumentById.mockResolvedValue(null);
+      global.mockCouchdbService.getById.mockResolvedValue(null);
 
       const event = await Event.findById('nonexistent');
       expect(event).toBeNull();

backend/models/Event.js

@@ -1,213 +1,377 @@
 const couchdbService = require("../services/couchdbService");
+const { 
+  ValidationError,
+  NotFoundError, 
+  DatabaseError, 
+  withErrorHandling,
+  createErrorContext,
+  logModelError
+} = require("../utils/modelErrors");
 
 class Event {
-  static async create(eventData) {
-    const event = {
-      _id: `event_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
-      type: "event",
-      title: eventData.title,
-      description: eventData.description,
-      date: eventData.date,
-      location: eventData.location,
-      participants: [],
-      participantsCount: 0,
-      status: eventData.status || "upcoming",
-      createdAt: new Date().toISOString(),
-      updatedAt: new Date().toISOString()
-    };
+  constructor(data) {
+    // Handle both new documents and database documents
+    const isNew = !data._id;
+    
+    // For new documents, validate required fields
+    if (isNew) {
+      if (!data.title || data.title.trim() === '') {
+        throw new ValidationError('Title is required', 'title', data.title);
+      }
+      if (!data.description || data.description.trim() === '') {
+        throw new ValidationError('Description is required', 'description', data.description);
+      }
+      if (!data.date) {
+        throw new ValidationError('Date is required', 'date', data.date);
+      }
+      if (!data.location) {
+        throw new ValidationError('Location is required', 'location', data.location);
+      }
 
-    return await couchdbService.create(event);
+      // Validate status
+      const validStatuses = ["upcoming", "ongoing", "completed", "cancelled"];
+      if (data.status && !validStatuses.includes(data.status)) {
+        throw new ValidationError('Invalid status', 'status', data.status);
+      }
+    }
+
+    this._id = data._id || null;
+    this._rev = data._rev || null;
+    this.type = data.type || "event";
+    this.title = data.title;
+    this.description = data.description;
+    this.date = data.date;
+    this.location = data.location;
+    this.organizer = data.organizer || null;
+    this.participants = data.participants || [];
+    this.participantsCount = data.participantsCount || 0;
+    this.status = data.status || "upcoming";
+    this.createdAt = data.createdAt || new Date().toISOString();
+    this.updatedAt = data.updatedAt || new Date().toISOString();
+  }
+
+  static async create(eventData) {
+    const errorContext = createErrorContext('Event', 'create', { 
+      title: eventData?.title,
+      date: eventData?.date,
+      location: eventData?.location 
+    });
+    
+    return await withErrorHandling(async () => {
+      const event = new Event(eventData);
+      event._id = `event_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
+      
+      const createdEvent = await couchdbService.createDocument(event.toJSON());
+      return new Event(createdEvent);
+    }, errorContext);
   }
 
   static async findById(eventId) {
-    return await couchdbService.getById(eventId);
+    const errorContext = createErrorContext('Event', 'findById', { eventId });
+    
+    return await withErrorHandling(async () => {
+      const doc = await couchdbService.getById(eventId);
+      if (doc && doc.type === "event") {
+        return new Event(doc);
+      }
+      return null;
+    }, errorContext);
   }
 
   static async find(query = {}, options = {}) {
-    const defaultQuery = {
-      type: "event",
-      ...query
-    };
+    const errorContext = createErrorContext('Event', 'find', { query, options });
+    
+    return await withErrorHandling(async () => {
+      const defaultQuery = {
+        type: "event",
+        ...query
+      };
 
-    return await couchdbService.find({
-      selector: defaultQuery,
-      ...options
-    });
+      return await couchdbService.find({
+        selector: defaultQuery,
+        ...options
+      });
+    }, errorContext);
   }
 
   static async findOne(query) {
-    const events = await this.find(query, { limit: 1 });
-    return events[0] || null;
+    const errorContext = createErrorContext('Event', 'findOne', { query });
+    
+    return await withErrorHandling(async () => {
+      const events = await this.find(query, { limit: 1 });
+      return events[0] || null;
+    }, errorContext);
   }
 
   static async update(eventId, updateData) {
-    const event = await this.findById(eventId);
-    if (!event) {
-      throw new Error("Event not found");
-    }
+    const errorContext = createErrorContext('Event', 'update', { eventId, updateData });
+    
+    return await withErrorHandling(async () => {
+      const event = await this.findById(eventId);
+      if (!event) {
+        throw new NotFoundError('Event', eventId);
+      }
 
-    const updatedEvent = {
-      ...event,
-      ...updateData,
-      updatedAt: new Date().toISOString()
-    };
+      const updatedEvent = {
+        ...event.toJSON(),
+        ...updateData,
+        updatedAt: new Date().toISOString()
+      };
 
-    return await couchdbService.update(eventId, updatedEvent);
+      const result = await couchdbService.update(eventId, updatedEvent);
+      return new Event(result);
+    }, errorContext);
   }
 
   static async delete(eventId) {
-    return await couchdbService.delete(eventId);
+    const errorContext = createErrorContext('Event', 'delete', { eventId });
+    
+    return await withErrorHandling(async () => {
+      const event = await this.findById(eventId);
+      if (!event) {
+        throw new NotFoundError('Event', eventId);
+      }
+      
+      return await couchdbService.delete(eventId);
+    }, errorContext);
   }
 
   static async addParticipant(eventId, userId, userName, userProfilePicture) {
-    const event = await this.findById(eventId);
-    if (!event) {
-      throw new Error("Event not found");
-    }
+    const errorContext = createErrorContext('Event', 'addParticipant', { eventId, userId });
+    
+    return await withErrorHandling(async () => {
+      const event = await this.findById(eventId);
+      if (!event) {
+        throw new NotFoundError('Event', eventId);
+      }
 
-    // Check if user is already a participant
-    const existingParticipant = event.participants.find(p => p.userId === userId);
-    if (existingParticipant) {
-      throw new Error("User already participating in this event");
-    }
+      // Check if user is already a participant
+      const existingParticipant = event.participants.find(p => p.userId === userId);
+      if (existingParticipant) {
+        throw new ValidationError('User already participating in this event', 'userId', userId);
+      }
 
-    // Add participant with embedded user data
-    const newParticipant = {
-      userId: userId,
-      name: userName,
-      profilePicture: userProfilePicture || "",
-      joinedAt: new Date().toISOString()
-    };
+      // Add participant with embedded user data
+      const newParticipant = {
+        userId: userId,
+        name: userName,
+        profilePicture: userProfilePicture || "",
+        joinedAt: new Date().toISOString()
+      };
 
-    event.participants.push(newParticipant);
-    event.participantsCount = event.participants.length;
-    event.updatedAt = new Date().toISOString();
+      event.participants.push(newParticipant);
+      event.participantsCount = event.participants.length;
+      event.updatedAt = new Date().toISOString();
 
-    return await couchdbService.update(eventId, event);
+      const result = await couchdbService.update(eventId, event.toJSON());
+      return new Event(result);
+    }, errorContext);
   }
 
   static async removeParticipant(eventId, userId) {
-    const event = await this.findById(eventId);
-    if (!event) {
-      throw new Error("Event not found");
-    }
+    const errorContext = createErrorContext('Event', 'removeParticipant', { eventId, userId });
+    
+    return await withErrorHandling(async () => {
+      const event = await this.findById(eventId);
+      if (!event) {
+        throw new NotFoundError('Event', eventId);
+      }
 
-    // Remove participant
-    event.participants = event.participants.filter(p => p.userId !== userId);
-    event.participantsCount = event.participants.length;
-    event.updatedAt = new Date().toISOString();
+      // Remove participant
+      event.participants = event.participants.filter(p => p.userId !== userId);
+      event.participantsCount = event.participants.length;
+      event.updatedAt = new Date().toISOString();
 
-    return await couchdbService.update(eventId, event);
+      const result = await couchdbService.update(eventId, event.toJSON());
+      return new Event(result);
+    }, errorContext);
   }
 
   static async updateStatus(eventId, newStatus) {
-    const validStatuses = ["upcoming", "ongoing", "completed", "cancelled"];
-    if (!validStatuses.includes(newStatus)) {
-      throw new Error("Invalid status");
-    }
+    const errorContext = createErrorContext('Event', 'updateStatus', { eventId, newStatus });
+    
+    return await withErrorHandling(async () => {
+      const validStatuses = ["upcoming", "ongoing", "completed", "cancelled"];
+      if (!validStatuses.includes(newStatus)) {
+        throw new ValidationError('Invalid status', 'status', newStatus);
+      }
 
-    return await this.update(eventId, { status: newStatus });
+      return await this.update(eventId, { status: newStatus });
+    }, errorContext);
   }
 
   static async findByStatus(status) {
-    return await this.find({ status });
+    const errorContext = createErrorContext('Event', 'findByStatus', { status });
+    
+    return await withErrorHandling(async () => {
+      return await this.find({ status });
+    }, errorContext);
   }
 
   static async findByDateRange(startDate, endDate) {
-    return await couchdbService.find({
-      selector: {
-        type: "event",
-        date: {
-          $gte: startDate.toISOString(),
-          $lte: endDate.toISOString()
-        }
-      },
-      sort: [{ date: "asc" }]
-    });
+    const errorContext = createErrorContext('Event', 'findByDateRange', { startDate, endDate });
+    
+    return await withErrorHandling(async () => {
+      return await couchdbService.find({
+        selector: {
+          type: "event",
+          date: {
+            $gte: startDate.toISOString(),
+            $lte: endDate.toISOString()
+          }
+        },
+        sort: [{ date: "asc" }]
+      });
+    }, errorContext);
   }
 
   static async findByParticipant(userId) {
-    return await couchdbService.view("events", "by-participant", {
-      key: userId,
-      include_docs: true
-    });
+    const errorContext = createErrorContext('Event', 'findByParticipant', { userId });
+    
+    return await withErrorHandling(async () => {
+      return await couchdbService.view("events", "by-participant", {
+        key: userId,
+        include_docs: true
+      });
+    }, errorContext);
   }
 
   static async getUpcomingEvents(limit = 10) {
-    const now = new Date().toISOString();
-    return await couchdbService.find({
-      selector: {
-        type: "event",
-        status: "upcoming",
-        date: { $gte: now }
-      },
-      sort: [{ date: "asc" }],
-      limit
-    });
+    const errorContext = createErrorContext('Event', 'getUpcomingEvents', { limit });
+    
+    return await withErrorHandling(async () => {
+      const now = new Date().toISOString();
+      return await couchdbService.find({
+        selector: {
+          type: "event",
+          status: "upcoming",
+          date: { $gte: now }
+        },
+        sort: [{ date: "asc" }],
+        limit
+      });
+    }, errorContext);
   }
 
   static async getAllPaginated(page = 1, limit = 10) {
-    const skip = (page - 1) * limit;
+    const errorContext = createErrorContext('Event', 'getAllPaginated', { page, limit });
     
-    const events = await couchdbService.find({
-      selector: { type: "event" },
-      sort: [{ date: "desc" }],
-      skip,
-      limit
-    });
+    return await withErrorHandling(async () => {
+      const skip = (page - 1) * limit;
+      
+      const events = await couchdbService.find({
+        selector: { type: "event" },
+        sort: [{ date: "desc" }],
+        skip,
+        limit
+      });
 
-    // Get total count
-    const totalCount = await couchdbService.find({
-      selector: { type: "event" },
-      fields: ["_id"]
-    });
+      // Get total count
+      const totalCount = await couchdbService.find({
+        selector: { type: "event" },
+        fields: ["_id"]
+      });
 
-    return {
-      events,
-      pagination: {
-        page,
-        limit,
-        totalCount: totalCount.length,
-        totalPages: Math.ceil(totalCount.length / limit)
-      }
-    };
+      return {
+        events,
+        pagination: {
+          page,
+          limit,
+          totalCount: totalCount.length,
+          totalPages: Math.ceil(totalCount.length / limit)
+        }
+      };
+    }, errorContext);
   }
 
   static async getEventsByUser(userId) {
-    return await this.find({
-      "participants": { $elemMatch: { userId: userId } }
+    const errorContext = createErrorContext('Event', 'getEventsByUser', { userId });
+    
+    return await withErrorHandling(async () => {
+      return await this.find({
+        "participants": { $elemMatch: { userId: userId } }
+      });
+    }, errorContext);
+  }
+
+  // Convert to CouchDB document format
+  toJSON() {
+    return {
+      _id: this._id,
+      _rev: this._rev,
+      type: this.type,
+      title: this.title,
+      description: this.description,
+      date: this.date,
+      location: this.location,
+      organizer: this.organizer,
+      participants: this.participants,
+      participantsCount: this.participantsCount,
+      status: this.status,
+      createdAt: this.createdAt,
+      updatedAt: this.updatedAt
+    };
+  }
+
+  // Instance save method
+  async save() {
+    const errorContext = createErrorContext('Event', 'save', { 
+      id: this._id,
+      isNew: !this._id 
     });
+    
+    return await withErrorHandling(async () => {
+      if (!this._id) {
+        // New document
+        this._id = `event_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
+        const created = await couchdbService.createDocument(this.toJSON());
+        this._rev = created._rev;
+        return this;
+      } else {
+        // Update existing document
+        this.updatedAt = new Date().toISOString();
+        const updated = await couchdbService.updateDocument(this.toJSON());
+        this._rev = updated._rev;
+        return this;
+      }
+    }, errorContext);
   }
 
   // Migration helper
   static async migrateFromMongo(mongoEvent) {
-    const eventData = {
-      title: mongoEvent.title,
-      description: mongoEvent.description,
-      date: mongoEvent.date,
-      location: mongoEvent.location,
-      status: mongoEvent.status || "upcoming"
-    };
+    const errorContext = createErrorContext('Event', 'migrateFromMongo', { 
+      mongoEventId: mongoEvent._id 
+    });
+    
+    return await withErrorHandling(async () => {
+      const eventData = {
+        title: mongoEvent.title,
+        description: mongoEvent.description,
+        date: mongoEvent.date,
+        location: mongoEvent.location,
+        status: mongoEvent.status || "upcoming"
+      };
 
-    // Create event without participants first
-    const event = await this.create(eventData);
+      // Create event without participants first
+      const event = await this.create(eventData);
 
-    // If there are participants, add them with embedded user data
-    if (mongoEvent.participants && mongoEvent.participants.length > 0) {
-      for (const participantId of mongoEvent.participants) {
-        try {
-          // Get user data to embed
-          const user = await couchdbService.findUserById(participantId.toString());
-          if (user) {
-            await this.addParticipant(event._id, participantId.toString(), user.name, user.profilePicture);
+      // If there are participants, add them with embedded user data
+      if (mongoEvent.participants && mongoEvent.participants.length > 0) {
+        for (const participantId of mongoEvent.participants) {
+          try {
+            // Get user data to embed
+            const user = await couchdbService.findUserById(participantId.toString());
+            if (user) {
+              await this.addParticipant(event._id, participantId.toString(), user.name, user.profilePicture);
+            }
+          } catch (error) {
+            console.error(`Error migrating participant ${participantId}:`, error.message);
           }
-        } catch (error) {
-          console.error(`Error migrating participant ${participantId}:`, error.message);
         }
       }
-    }
 
-    return event;
+      return event;
+    }, errorContext);
   }
 }