Improved test

test/builder_merge_test.go

@@ -0,0 +1,56 @@
+package integration
+
+import (
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/marte-community/marte-dev-tools/internal/builder"
+)
+
+func TestBuilderMergeNodes(t *testing.T) {
+	// Two files without package, defining SAME root node +App.
+	// This triggers merging logic in Builder.
+	
+	content1 := `
++App = {
+    Field1 = 10
+    +Sub = { Val = 1 }
+}
+`
+	content2 := `
++App = {
+    Field2 = 20
+    +Sub = { Val2 = 2 }
+}
+`
+	f1, _ := os.CreateTemp("", "merge1.marte")
+	f1.WriteString(content1)
+	f1.Close()
+	defer os.Remove(f1.Name())
+
+	f2, _ := os.CreateTemp("", "merge2.marte")
+	f2.WriteString(content2)
+	f2.Close()
+	defer os.Remove(f2.Name())
+
+	b := builder.NewBuilder([]string{f1.Name(), f2.Name()}, nil)
+
+	outF, _ := os.CreateTemp("", "out_merge.marte")
+	defer os.Remove(outF.Name())
+	
+	err := b.Build(outF)
+	if err != nil {
+		t.Fatalf("Build failed: %v", err)
+	}
+	outF.Close()
+
+	outContent, _ := os.ReadFile(outF.Name())
+	outStr := string(outContent)
+
+	if !strings.Contains(outStr, "Field1 = 10") { t.Error("Missing Field1") }
+	if !strings.Contains(outStr, "Field2 = 20") { t.Error("Missing Field2") }
+	if !strings.Contains(outStr, "+Sub = {") { t.Error("Missing Sub") }
+	if !strings.Contains(outStr, "Val = 1") { t.Error("Missing Sub.Val") }
+	if !strings.Contains(outStr, "Val2 = 2") { t.Error("Missing Sub.Val2") }
+}