Add complete test scaffolding support with --test flag for API projects (#5176)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: kevwan <1918356+kevwan@users.noreply.github.com>

tools/goctl/api/gogen/svc_test.tpl

@@ -0,0 +1,60 @@
+// Code scaffolded by goctl. Safe to edit.
+// goctl {{.version}}
+
+package svc
+
+import (
+	"testing"
+
+	"{{.projectPkg}}/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewServiceContext(t *testing.T) {
+	tests := []struct {
+		name   string
+		config config.Config
+		setup  func() config.Config
+	}{
+		{
+			name: "default config",
+			setup: func() config.Config {
+				return config.Config{}
+			},
+		},
+		{
+			name: "valid config", 
+			setup: func() config.Config {
+				return config.Config{
+					// TODO: Add valid config values here
+				}
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := tt.setup()
+			svcCtx := NewServiceContext(c)
+
+			// Basic assertions
+			require.NotNil(t, svcCtx)
+			assert.Equal(t, c, svcCtx.Config)
+
+			// TODO: Add additional assertions for middleware and dependencies
+		})
+	}
+}
+
+func TestServiceContext_Initialization(t *testing.T) {
+	c := config.Config{}
+	svcCtx := NewServiceContext(c)
+
+	// Verify service context is properly initialized
+	assert.NotNil(t, svcCtx)
+	assert.Equal(t, c, svcCtx.Config)
+
+	// TODO: Add tests for middleware initialization if any
+	// TODO: Add tests for external dependencies if any
+}