Initial commit: Inventory Barcode System

__tests__/InventoryModel.test.js

@@ -0,0 +1,165 @@
+const Inventory = require('../models/Inventory');
+
+describe('Inventory Model - Basic Tests', () => {
+    test('should create inventory instance', () => {
+        const inventory = new Inventory({
+            product_id: 1,
+            current_level: 50,
+            minimum_level: 10,
+            updated_by: 'testuser'
+        });
+
+        expect(inventory.product_id).toBe(1);
+        expect(inventory.current_level).toBe(50);
+        expect(inventory.minimum_level).toBe(10);
+        expect(inventory.updated_by).toBe('testuser');
+    });
+
+    test('should validate required product_id', () => {
+        const inventory = new Inventory({
+            current_level: 50,
+            minimum_level: 10
+        });
+        const validation = inventory.validate();
+
+        expect(validation.isValid).toBe(false);
+        expect(validation.errors).toContain('Product ID is required and must be a number');
+    });
+
+    test('should validate current_level is non-negative', () => {
+        const inventory = new Inventory({
+            product_id: 1,
+            current_level: -5,
+            minimum_level: 10
+        });
+        const validation = inventory.validate();
+
+        expect(validation.isValid).toBe(false);
+        expect(validation.errors).toContain('Current level must be a non-negative number');
+    });
+
+    test('should pass validation with valid data', () => {
+        const inventory = new Inventory({
+            product_id: 1,
+            current_level: 50,
+            minimum_level: 10,
+            maximum_level: 100,
+            updated_by: 'testuser'
+        });
+        const validation = inventory.validate();
+
+        expect(validation.isValid).toBe(true);
+        expect(validation.errors).toHaveLength(0);
+    });
+
+    test('should convert to JSON', () => {
+        const inventoryData = {
+            id: 1,
+            product_id: 1,
+            current_level: 50,
+            minimum_level: 10,
+            maximum_level: 100,
+            last_updated: '2023-01-01 00:00:00',
+            updated_by: 'testuser',
+            version: 1
+        };
+
+        const inventory = new Inventory(inventoryData);
+        const json = inventory.toJSON();
+
+        expect(json).toEqual(inventoryData);
+    });
+});
+
+describe('Inventory Model - Database Tests', () => {
+    const database = require('../models/database');
+    let testProduct;
+
+    beforeAll(async () => {
+        // Initialize database for testing
+        database.initialize();
+    });
+
+    afterAll(() => {
+        // Close database connection
+        database.close();
+    });
+
+    beforeEach(() => {
+        // Clear tables before each test
+        const db = database.getDatabase();
+        db.exec('DELETE FROM inventory_history');
+        db.exec('DELETE FROM inventory');
+        db.exec('DELETE FROM products');
+
+        // Create a test product
+        const insertStmt = db.prepare(`
+      INSERT INTO products (product_code, description, category, unit_of_measure)
+      VALUES (?, ?, ?, ?)
+    `);
+        const result = insertStmt.run('TEST001', 'Test Product', 'Electronics', 'pieces');
+        testProduct = { id: result.lastInsertRowid, product_code: 'TEST001' };
+    });
+
+    test('should create inventory record for a product', async () => {
+        const inventory = await Inventory.createForProduct(
+            testProduct.id,
+            100,
+            10,
+            200,
+            'testuser'
+        );
+
+        expect(inventory.product_id).toBe(testProduct.id);
+        expect(inventory.current_level).toBe(100);
+        expect(inventory.minimum_level).toBe(10);
+        expect(inventory.maximum_level).toBe(200);
+        expect(inventory.updated_by).toBe('testuser');
+        expect(inventory.id).toBeDefined();
+    });
+
+    test('should update inventory level and create audit record', async () => {
+        // Create initial inventory
+        await Inventory.createForProduct(testProduct.id, 100, 10, 200, 'system');
+
+        const updatedInventory = await Inventory.updateInventoryLevel(
+            testProduct.id,
+            150,
+            'Restocking from supplier',
+            'testuser'
+        );
+
+        expect(updatedInventory.product_id).toBe(testProduct.id);
+        expect(updatedInventory.current_level).toBe(150);
+        expect(updatedInventory.updated_by).toBe('testuser');
+        expect(updatedInventory.version).toBe(2); // Version should increment
+
+        // Verify audit trail was created
+        const history = await Inventory.getInventoryHistory(testProduct.id);
+        expect(history).toHaveLength(2); // Initial creation + update
+        expect(history[0].old_level).toBe(100);
+        expect(history[0].new_level).toBe(150);
+        expect(history[0].change_reason).toBe('Restocking from supplier');
+        expect(history[0].updated_by).toBe('testuser');
+    });
+
+    test('should handle concurrent updates with optimistic locking', async () => {
+        // Create initial inventory
+        await Inventory.createForProduct(testProduct.id, 100, 10, 200, 'system');
+
+        // Simulate concurrent access by getting the same record twice
+        const inventory1 = await Inventory.getByProductId(testProduct.id);
+        const inventory2 = await Inventory.getByProductId(testProduct.id);
+
+        // First update should succeed
+        inventory1.current_level = 120;
+        inventory1.updated_by = 'user1';
+        await inventory1.save();
+
+        // Second update should fail due to version mismatch
+        inventory2.current_level = 110;
+        inventory2.updated_by = 'user2';
+
+        await expect(inventory2.save()).rejects.toThrow('Concurrent update detected');
+    });
+});