fix: preserve Godot virtual callbacks in unused-code checks

src/core/callback_test.go

@@ -0,0 +1,24 @@
+package core
+
+import (
+	"github.com/aviorstudio/gdlint/src/models"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestUnusedAnalysisKeepsEngineCallbacks(t *testing.T) {
+	root := t.TempDir()
+	script := "@tool\nextends Control\n\nfunc _get_configuration_warnings() -> PackedStringArray:\n\treturn PackedStringArray()\n\nfunc _get_property_list() -> Array:\n\treturn []\n"
+	if err := os.WriteFile(filepath.Join(root, "example.gd"), []byte(script), 0600); err != nil {
+		t.Fatal(err)
+	}
+	config := &models.LintConfig{Errors: models.ErrorSection{UnusedFunctions: true}}
+	results, err := NewAnalyzer(root, config).Analyze()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(results.UnusedFunctions) != 0 {
+		t.Fatalf("engine callbacks reported unused: %+v", results.UnusedFunctions)
+	}
+}

src/models/entity.go

@@ -1,6 +1,9 @@
 package models
 
-import "fmt"
+import (
+	"fmt"
+	"github.com/aviorstudio/gdlint/src/patterns"
+)
 
 type EntityType string
 
@@ -49,19 +52,7 @@ func (e *Entity) IsProtected() bool {
 		return false
 	}
 
-	protectedPrefixes := []string{
-		"_ready", "_init", "_enter_tree", "_exit_tree",
-		"_process", "_physics_process", "_input", "_unhandled_input",
-		"_draw", "_gui_input", "_notification",
-	}
-
-	for _, prefix := range protectedPrefixes {
-		if e.Name == prefix {
-			return true
-		}
-	}
-
-	if len(e.Name) >= 4 && e.Name[:4] == "_on_" {
+	if patterns.IsProtectedFunction(e.Name) {
 		return true
 	}
 

src/models/entity_test.go

@@ -0,0 +1,16 @@
+package models
+
+import "testing"
+
+func TestGodotVirtualCallbacksAreProtectedWithoutCalls(t *testing.T) {
+	for _, name := range []string{"_get_configuration_warnings", "_get_property_list", "_property_can_revert", "_property_get_revert", "_get", "_set", "_to_string", "_ready", "_on_pressed"} {
+		if !(&Entity{Type: EntityFunction, Name: name}).IsProtected() {
+			t.Errorf("engine callback %s must survive unused-code cleanup", name)
+		}
+	}
+	for _, entity := range []*Entity{{Type: EntityFunction, Name: "_get_configuration_warnings_extra"}, {Type: EntityFunction, Name: "_helper"}, {Type: EntitySignal, Name: "_get_configuration_warnings"}} {
+		if entity.IsProtected() {
+			t.Errorf("ordinary entity must still require a use: %+v", entity)
+		}
+	}
+}