add extension

file/lib/sentry_file.dart

@@ -1 +1,2 @@
 export 'src/sentry_file.dart';
+export 'src/sentry_file_extension.dart';

file/lib/src/sentry_file.dart

@@ -11,6 +11,21 @@ import 'package:sentry/sentry.dart';
 
 typedef Callback<T> = FutureOr<T> Function();
 
+/// The Sentry wrapper for the File implementation that starts a span
+/// out of the active transaction in the scope.
+/// The span is started before the operation is executed and finished after.
+/// Example:
+///
+/// ```dart
+/// final file = File('test.txt');
+/// final sentryFile = SentryFile(file);
+/// // span starts
+/// await sentryFile.writeAsString('Hello World');
+/// // span finishes
+/// ```
+///
+/// All the copy, create, delete, open, rename, read, and write operations are
+/// supported.
 class SentryFile implements File {
   SentryFile(
     this._file, {

file/lib/src/sentry_file_extension.dart

@@ -0,0 +1,24 @@
+import 'dart:io';
+
+import '../sentry_file.dart';
+
+extension SentryFileExtension on File {
+  /// The Sentry wrapper for the File implementation that starts a span
+  /// out of the active transaction in the scope.
+  /// The span is started before the operation is executed and finished after.
+  /// Example:
+  ///
+  /// ```dart
+  /// final file = File('test.txt');
+  /// final sentryFile = file.sentryTrace();
+  /// // span starts
+  /// await sentryFile.writeAsString('Hello World');
+  /// // span finishes
+  /// ```
+  ///
+  /// All the copy, create, delete, open, rename, read, and write operations are
+  /// supported.
+  SentryFile sentryTrace() {
+    return SentryFile(this);
+  }
+}