Force Check Duplicates

README.md

@@ -35,6 +35,8 @@ tools/             built development binary output
 
 - `sow-module` uses `sow-toolkit` for `build-module`, `extract`, `validate`, `compare`, and `apply-hak-manifest`
 - `sow-assets` uses `sow-toolkit` for `build-haks` and validation
+  - validation now fails early if duplicate asset resources would collide inside the same generated HAK
+  - duplicate resources split across different HAK groups remain warnings because later HAK order can still override earlier content at runtime
 - `sow-module` now also uses `sow-toolkit` for the early topdata bridge:
   - `validate-topdata`
   - `build-topdata`

internal/pipeline/pipeline_test.go

@@ -1052,7 +1052,7 @@ func TestBuildHAKsFailsForDuplicateResourcesInSameHAK(t *testing.T) {
 	if err == nil {
 		t.Fatal("expected duplicate same-hak build error")
 	}
-	if !strings.Contains(err.Error(), "conflicts") {
+	if !strings.Contains(err.Error(), "validation failed with 1 error(s)") {
 		t.Fatalf("unexpected error: %v", err)
 	}
 }

internal/validator/validator.go

@@ -312,7 +312,7 @@ func classifyAssetDuplicates(report *Report, occurrences map[string][]assetOccur
 		slices.Sort(paths)
 
 		if len(groups) == 1 {
-			report.add(entries[0].Path, fmt.Sprintf("duplicate asset resource %s appears multiple times in hak group %q (%s); build will fail if duplicates land in the same generated hak", key, groups[0], strings.Join(paths, ", ")), SeverityWarning)
+			report.add(entries[0].Path, fmt.Sprintf("duplicate asset resource %s appears multiple times in hak group %q (%s); build will fail if duplicates land in the same generated hak", key, groups[0], strings.Join(paths, ", ")), SeverityError)
 			continue
 		}
 

internal/validator/validator_test.go

@@ -54,6 +54,54 @@ func TestValidateProjectWarnsForCrossHAKDuplicateAssets(t *testing.T) {
 	}
 }
 
+func TestValidateProjectErrorsForSameHAKDuplicateAssets(t *testing.T) {
+	root := t.TempDir()
+	mustMkdir(t, filepath.Join(root, "src"))
+	mustMkdir(t, filepath.Join(root, "assets", "core", "a"))
+	mustMkdir(t, filepath.Join(root, "assets", "core", "b"))
+	mustMkdir(t, filepath.Join(root, "build"))
+
+	mustWriteFile(t, filepath.Join(root, "nwn-tool.json"), `{
+  "module": {
+    "name": "Test Assets",
+    "resref": "testassets"
+  },
+  "paths": {
+    "source": "src",
+    "assets": "assets",
+    "build": "build"
+  },
+  "haks": [
+    { "name": "core", "priority": 1, "max_bytes": 0, "split": false, "include": ["core/**"] }
+  ]
+}
+`)
+	mustWriteFile(t, filepath.Join(root, "assets", "core", "a", "shared.mdl"), "one")
+	mustWriteFile(t, filepath.Join(root, "assets", "core", "b", "shared.mdl"), "two")
+
+	p, err := project.Load(root)
+	if err != nil {
+		t.Fatalf("load project: %v", err)
+	}
+	if err := p.ValidateLayout(); err != nil {
+		t.Fatalf("validate layout: %v", err)
+	}
+	if err := p.Scan(); err != nil {
+		t.Fatalf("scan: %v", err)
+	}
+
+	report := ValidateProject(p)
+	if !report.HasErrors() {
+		t.Fatalf("expected same-hak duplicate to be an error, got %#v", report.Diagnostics)
+	}
+	if report.ErrorCount() != 1 {
+		t.Fatalf("expected 1 error, got %d (%#v)", report.ErrorCount(), report.Diagnostics)
+	}
+	if report.WarningCount() != 0 {
+		t.Fatalf("expected no warnings, got %d (%#v)", report.WarningCount(), report.Diagnostics)
+	}
+}
+
 func TestValidateProjectWarnsForUppercaseResourceNames(t *testing.T) {
 	root := t.TempDir()
 	mustMkdir(t, filepath.Join(root, "src", "blueprints", "items"))