Implement PUT /user/{userId}/allowance/{allowanceId} (#52)

Closes #17

Reviewed-on: #52

backend/api_test.go

@@ -492,6 +492,34 @@ func TestGetUserByAllowanceByIdBadAllowanceId(t *testing.T) {
 	e.GET("/user/1/allowance/bad").Expect().Status(400)
 }
 
+func TestPutAllowanceById(t *testing.T) {
+	e := startServer(t)
+
+	// Create a new allowance
+	requestBody := map[string]interface{}{
+		"name":   TestAllowanceName,
+		"target": 5000,
+		"weight": 10,
+	}
+	resp := e.POST("/user/1/allowance").WithJSON(requestBody).Expect().Status(201).JSON().Object()
+	allowanceId := int(resp.Value("id").Number().Raw())
+
+	// Update the allowance
+	updateRequest := map[string]interface{}{
+		"name":   "Updated Allowance",
+		"target": 6000,
+		"weight": 15,
+	}
+	e.PUT("/user/1/allowance/" + strconv.Itoa(allowanceId)).WithJSON(updateRequest).Expect().Status(200)
+
+	// Verify the allowance is updated
+	result := e.GET("/user/1/allowance/" + strconv.Itoa(allowanceId)).Expect().Status(200).JSON().Object()
+	result.Value("id").IsEqual(allowanceId)
+	result.Value("name").IsEqual("Updated Allowance")
+	result.Value("target").IsEqual(6000)
+	result.Value("weight").IsEqual(15)
+}
+
 func getDelta(base time.Time, delta float64) (time.Time, time.Time) {
 	start := base.Add(-time.Duration(delta) * time.Second)
 	end := base.Add(time.Duration(delta) * time.Second)