Improve library examples loading process by filtering out unneeded directories

Author: MatteoPologruto

arduino/libraries/loader.go

@@ -20,7 +20,6 @@ import (
 	"strings"
 
 	"github.com/arduino/arduino-cli/arduino/globals"
-	"github.com/arduino/arduino-cli/arduino/sketch"
 	"github.com/arduino/go-paths-helper"
 	properties "github.com/arduino/go-properties-orderedmap"
 	"github.com/pkg/errors"
@@ -176,20 +175,11 @@ func addExamples(lib *Library) error {
 }
 
 func addExamplesToPathList(examplesPath *paths.Path, list *paths.PathList) error {
-	files, err := examplesPath.ReadDir()
+	files, err := examplesPath.ReadDirRecursiveFiltered(nil, filterExamplesDirs)
 	if err != nil {
 		return err
 	}
-	for _, file := range files {
-		_, err := sketch.New(file)
-		if err == nil {
-			list.Add(file)
-		} else if file.IsDir() {
-			if err := addExamplesToPathList(file, list); err != nil {
-				return err
-			}
-		}
-	}
+	list.AddAll(files)
 	return nil
 }
 
@@ -208,3 +198,8 @@ func containsHeaderFile(d *paths.Path) (bool, error) {
 	dirContent.FilterSuffix(headerExtensions...)
 	return len(dirContent) > 0, nil
 }
+
+// filterExamplesDirs filters out any directory that does not contain a ".ino" or ".pde" file
+func filterExamplesDirs(dir *paths.Path) bool {
+	return dir.Join(dir.Base()+".ino").Exist() || dir.Join(dir.Base()+".pde").Exist()
+}