Added additional testcases.

__tests__/api/bikes.test.ts

@@ -162,6 +162,42 @@ describe('Bikes API', () => {
 
       expect(bikes).toHaveLength(0)
     })
+
+    it('should include wearParts with maintenanceHistory when fetching a bike', async () => {
+      // Create bike, part and maintenance
+      const bike = await prisma.bike.create({ data: { name: `Include Test ${Date.now()}` } })
+      const part = await prisma.wearPart.create({
+        data: {
+          bikeId: bike.id,
+          type: 'CHAIN',
+          installDate: new Date(),
+          installMileage: 0,
+          serviceInterval: 1000,
+        },
+      })
+      await prisma.maintenanceHistory.create({
+        data: {
+          wearPartId: part.id,
+          date: new Date(),
+          mileage: 0,
+          action: 'INSTALL',
+        },
+      })
+
+      const found = await prisma.bike.findUnique({
+        where: { id: bike.id },
+        include: {
+          wearParts: {
+            include: { maintenanceHistory: true },
+          },
+        },
+      })
+
+      expect(found).toBeDefined()
+      expect(found?.wearParts).toBeDefined()
+      expect(found?.wearParts[0].maintenanceHistory).toBeDefined()
+      expect(found?.wearParts[0].maintenanceHistory.length).toBeGreaterThanOrEqual(1)
+    })
   })
 
   describe('GET /api/bikes/[id]', () => {