fix: fix IsDirEmpty and add tests (#76)

file/dir.go

@@ -32,8 +32,8 @@ func IsDir(path string) (bool, error) {
 	return false, err
 }
 
-// IsDirEmpty returns whether the given directory path is empty.
+// IsDirEmpty checks if the directory at the given path is empty.
-// If the path does not exist or is not a directory, it returns (false, err).
+// It returns true if the directory is empty, false if not empty, or an error if there was a problem checking it.
 func IsDirEmpty(path string) (bool, error) {
 	f, err := os.Open(path)
 	if err != nil {
@@ -43,7 +43,7 @@ func IsDirEmpty(path string) (bool, error) {
 
 	_, err = f.Readdir(1)
 	if err == nil {
-		return true, nil
+		return false, nil
 	}
 
 	if errors.Is(err, io.EOF) {

file/dir_test.go

@@ -0,0 +1,69 @@
+package file
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestIsDirEmpty(t *testing.T) {
+	t.Run("empty directory", func(t *testing.T) {
+		dir, err := os.MkdirTemp("", "test")
+		if err != nil {
+			t.Fatalf("failed to create temp dir: %v", err)
+		}
+		defer os.RemoveAll(dir)
+
+		isEmpty, err := IsDirEmpty(dir)
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+
+		if !isEmpty {
+			t.Error("expected directory to be empty")
+		}
+	})
+
+	t.Run("non-empty directory", func(t *testing.T) {
+		dir, err := os.MkdirTemp("", "test")
+		if err != nil {
+			t.Fatalf("failed to create temp dir: %v", err)
+		}
+		defer os.RemoveAll(dir)
+
+		file, err := os.CreateTemp(dir, "test")
+		if err != nil {
+			t.Fatalf("failed to create temp file: %v", err)
+		}
+
+		file.Close()
+
+		isEmpty, err := IsDirEmpty(dir)
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+
+		if isEmpty {
+			t.Error("expected directory to be non-empty")
+		}
+	})
+
+	t.Run("non-existent directory", func(t *testing.T) {
+		dir := filepath.Join(os.TempDir(), "non-existent")
+
+		isEmpty, err := IsDirEmpty(dir)
+		if err == nil {
+			t.Error("expected an error for non-existent directory")
+		}
+
+		if isEmpty {
+			t.Error("expected directory to be non-empty")
+		}
+
+		if !errors.Is(err, fs.ErrNotExist) {
+			t.Errorf("unexpected error: %v", err)
+		}
+	})
+}