Add POST /user/{userId}/goals (#26)

Closes #4

Reviewed-on: #26

backend/api_test.go

@@ -2,8 +2,9 @@ package main
 
 import (
 	"testing"
+
+	"github.com/gavv/httpexpect/v2"
 )
-import "github.com/gavv/httpexpect/v2"
 
 func startServer(t *testing.T) *httpexpect.Expect {
 	config := ServerConfig{
@@ -56,3 +57,95 @@ func TestGetUserGoalsBadId(t *testing.T) {
 	e := startServer(t)
 	e.GET("/user/bad-id/goals").Expect().Status(400)
 }
+
+func TestCreateUserGoal(t *testing.T) {
+	e := startServer(t)
+
+	// Create a new goal
+	requestBody := map[string]interface{}{
+		"name":   "Test Goal",
+		"target": 5000,
+		"weight": 10,
+	}
+
+	response := e.POST("/user/1/goals").
+		WithJSON(requestBody).
+		Expect().
+		Status(201).
+		JSON().Object()
+
+	// Verify the response has an ID
+	response.ContainsKey("id")
+	goalId := response.Value("id").Number().Raw()
+
+	// Verify the goal exists in the list of goals
+	goals := e.GET("/user/1/goals").
+		Expect().
+		Status(200).
+		JSON().Array()
+
+	goals.Length().IsEqual(1)
+
+	goal := goals.Value(0).Object()
+	goal.Value("id").IsEqual(goalId)
+	goal.Value("name").IsEqual("Test Goal")
+	goal.Value("target").IsEqual(5000)
+	goal.Value("weight").IsEqual(10)
+	goal.Value("progress").IsEqual(0)
+}
+
+func TestCreateUserGoalNoUser(t *testing.T) {
+	e := startServer(t)
+
+	requestBody := map[string]interface{}{
+		"name":   "Test Goal",
+		"target": 5000,
+		"weight": 10,
+	}
+
+	e.POST("/user/999/goals").
+		WithJSON(requestBody).
+		Expect().
+		Status(404)
+}
+
+func TestCreateUserGoalInvalidInput(t *testing.T) {
+	e := startServer(t)
+
+	// Test with empty name
+	requestBody := map[string]interface{}{
+		"name":   "",
+		"target": 5000,
+		"weight": 10,
+	}
+
+	e.POST("/user/1/goals").
+		WithJSON(requestBody).
+		Expect().
+		Status(400)
+
+	// Test with missing fields
+	invalidRequest := map[string]interface{}{
+		"target": 5000,
+	}
+
+	e.POST("/user/1/goals").
+		WithJSON(invalidRequest).
+		Expect().
+		Status(400)
+}
+
+func TestCreateUserGoalBadId(t *testing.T) {
+	e := startServer(t)
+
+	requestBody := map[string]interface{}{
+		"name":   "Test Goal",
+		"target": 5000,
+		"weight": 10,
+	}
+
+	e.POST("/user/bad-id/goals").
+		WithJSON(requestBody).
+		Expect().
+		Status(400)
+}