fix: auto-upcast for package functions, enum casts, stale cache

- Package-level functions now use rugo_upcast helpers (same as DotCall),
  so passing a QPushButton where a QObject is expected works everywhere
- Named enum type casts now detected in reclassified package functions
- Stale empty cache dirs are re-fetched instead of treated as cached
- Qt example: add Ctrl+Q shortcut, use string interpolation, clean up

Author: rubiojr

compiler/codegen.go

@@ -2673,7 +2673,7 @@ func (g *codeGen) generateGoBridgeCall(pkg string, sig *gobridge.GoFuncSig, argE
 			// Struct handle unwrapping: extract the inner Go struct from the wrapper.
 			if sig.StructCasts != nil {
 				if wrapType, ok := sig.StructCasts[i]; ok {
-					convertedArgs = append(convertedArgs, fmt.Sprintf("%s.(*%s).v", arg, wrapType))
+					convertedArgs = append(convertedArgs, fmt.Sprintf("rugo_upcast_%s(%s).v", wrapType, arg))
 					continue
 				}
 			}

examples/require_go_qt/.gitignore

@@ -0,0 +1 @@
+main

examples/require_go_qt/main.rugo

@@ -14,9 +14,8 @@
 #   rugo build main.rugo -o hello_qt && ./hello_qt
 
 # Require miqt/qt6 directly — the sub-path is part of the require path
-require "github.com/mappu/miqt/qt6@v0.13.0" as qt6
+require "github.com/mappu/miqt/qt6@v0.13.0"
 import "os"
-use "conv"
 
 # Rugo-side convenience layer using a hash with lambdas
 qt = {
@@ -44,7 +43,7 @@ layout.add_widget(lbl)
 btn = qt.button("Click Me")
 btn.on_clicked(fn()
   count = count + 1
-  lbl.set_text("Clicked: " + conv.to_s(count) + " times")
+  lbl.set_text("Clicked: #{count} times")
 end)
 layout.add_widget(btn)
 
@@ -54,5 +53,11 @@ quit_btn.on_clicked(fn()
 end)
 layout.add_widget(quit_btn)
 
+# Ctrl+Q shortcut (QKeySequence::Quit = 65)
+shortcut = qt6.new_qshortcut3(65, win)
+shortcut.on_activated(fn()
+  qt.quit()
+end)
+
 win.show()
 qt.exec()

gobridge/inspect.go

@@ -535,9 +535,15 @@ func reclassifyWithStructs(f ClassifiedFunc, structWrappers map[string]string, p
 			sig.FuncTypes[i] = ft
 		} else {
 			sig.Params = append(sig.Params, gt)
+			// Detect named types that need explicit casts (e.g., qt6.StandardKey).
+			if cast := namedTypeCast(t); cast != "" {
+				if sig.TypeCasts == nil {
+					sig.TypeCasts = make(map[int]string)
+				}
+				sig.TypeCasts[i] = cast
+			}
 		}
 	}
-
 	// Classify returns.
 	results := f.Sig.Results()
 	for i := 0; i < results.Len(); i++ {

remote/resolver.go

@@ -260,7 +260,7 @@ func (r *Resolver) resolveWithLock(rp *remotePath) (string, error) {
 
 	// For immutable versions, use the standard needsFetch logic.
 	if rp.isImmutable() {
-		if _, err := os.Stat(cacheDir); err == nil {
+		if info, err := os.Stat(cacheDir); err == nil && isDirWithContent(info, cacheDir) {
 			// Already cached. Record in lock file for completeness.
 			sha, err := gitRevParseSHA(cacheDir)
 			if err == nil {
@@ -321,3 +321,16 @@ func (r *Resolver) resolveWithLock(rp *remotePath) (string, error) {
 	r.trackResolved(moduleKey, versionLabel)
 	return finalDir, nil
 }
+
+// isDirWithContent returns true if the path is a directory with at least one entry.
+// Used to detect stale empty cache directories that should be re-fetched.
+func isDirWithContent(info os.FileInfo, path string) bool {
+	if !info.IsDir() {
+		return false
+	}
+	entries, err := os.ReadDir(path)
+	if err != nil {
+		return false
+	}
+	return len(entries) > 0
+}