Add support for adding allowance to ID=0 (#106)

Closes #102

Reviewed-on: #106

backend/api_test.go

@@ -764,7 +764,6 @@ func TestAddAllowanceSimple(t *testing.T) {
 	createTestAllowance(e, "Test Allowance 1", 1000, 1)
 
 	request := map[string]interface{}{
-		"id":          1,
 		"amount":      10,
 		"description": "Added to allowance 1",
 	}
@@ -783,6 +782,30 @@ func TestAddAllowanceSimple(t *testing.T) {
 	history.Value(0).Object().Value("description").String().IsEqual("Added to allowance 1")
 }
 
+func TestAddAllowanceIdZero(t *testing.T) {
+	e := startServer(t)
+
+	createTestAllowance(e, "Test Allowance 1", 1000, 1)
+
+	request := map[string]interface{}{
+		"amount":      10,
+		"description": "Added to allowance 1",
+	}
+	e.POST("/user/1/allowance/0/add").WithJSON(request).Expect().Status(200)
+
+	// Verify the allowance is updated
+	allowances := e.GET("/user/1/allowance").Expect().Status(200).JSON().Array()
+	allowances.Value(0).Object().Value("id").Number().IsEqual(0)
+	allowances.Value(0).Object().Value("progress").Number().InDelta(10.0, 0.01)
+
+	// Verify the history is updated
+	history := e.GET("/user/1/history").Expect().Status(200).JSON().Array()
+	history.Length().IsEqual(1)
+	history.Value(0).Object().Value("allowance").Number().InDelta(10.0, 0.01)
+	history.Value(0).Object().Value("timestamp").String().AsDateTime().InRange(getDelta(time.Now(), 2.0))
+	history.Value(0).Object().Value("description").String().IsEqual("Added to allowance 1")
+}
+
 func TestAddAllowanceWithSpillage(t *testing.T) {
 	e := startServer(t)
 
@@ -791,7 +814,6 @@ func TestAddAllowanceWithSpillage(t *testing.T) {
 	e.PUT("/user/1/allowance/0").WithJSON(UpdateAllowanceRequest{Weight: 1}).Expect().Status(200)
 
 	request := map[string]interface{}{
-		"id":          1,
 		"amount":      10,
 		"description": "Added to allowance 1",
 	}