[shared_preferences] Add shared preferences devtools (#6749)

This PR adds the shared_preferences_tools package. This package user the [devtools_extension](https://pub.dev/packages/devtools_extensions) tooling to create a tool for shared preferences. The idea of this PR came from @kenzieschmoll on this [issue](flutter/flutter#145433). Initially I've published this tool as a [separate package](https://pub.dev/packages/shared_preferences_tools), but this PR aims to bring the functionality to the main shared_preferences package. Once this PR gets merged I'll archive the `shared_preferences_tools` package. 

https://github.com/flutter/packages/assets/11666470/fcf71145-c330-4397-b62e-c0c4c8bc9f01

CODEOWNERS

@@ -124,3 +124,7 @@ packages/local_auth/local_auth_windows/**                @cbracken
 packages/path_provider/path_provider_windows/**          @cbracken
 packages/shared_preferences/shared_preferences_windows/** @cbracken
 packages/url_launcher/url_launcher_windows/**            @cbracken
+
+# - DevTools extensions
+# @adsonpleal is the actual maintainer of shared_preferences_tool but is not yet a committer, so can't be listed as the owner.
+packages/shared_preferences/shared_preferences_tool/**  @tarrinneal

packages/shared_preferences/shared_preferences/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.4.0
+
+* Adds shared preferences devtools extension
+
 ## 2.3.3
 
 * Clarifies scope of prefix handling in README.

packages/shared_preferences/shared_preferences/extension/devtools/.gitignore

@@ -0,0 +1 @@
+build

packages/shared_preferences/shared_preferences/extension/devtools/.pubignore

@@ -0,0 +1 @@
+!build

packages/shared_preferences/shared_preferences/extension/devtools/config.yaml

@@ -0,0 +1,4 @@
+name: shared_preferences
+issueTracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+shared_preferences%22
+version: 1.0.0
+materialIconCodePoint: '0xe683'

packages/shared_preferences/shared_preferences/lib/src/shared_preferences_async.dart

@@ -8,6 +8,8 @@ import 'package:flutter/foundation.dart';
 import 'package:shared_preferences_platform_interface/shared_preferences_async_platform_interface.dart';
 import 'package:shared_preferences_platform_interface/types.dart';
 
+import 'shared_preferences_devtools_extension_data.dart';
+
 /// Provides a persistent store for simple data.
 ///
 /// Data is persisted to and fetched from the disk asynchronously.
@@ -401,3 +403,10 @@ class SharedPreferencesWithCache {
     return _cacheOptions.allowList?.contains(key) ?? true;
   }
 }
+
+// Include an unused import to ensure this library is included
+// when running `flutter run -d chrome`.
+// Check this discussion for more info: https://github.com/flutter/packages/pull/6749/files/6eb1b4fdce1eba107294770d581713658ff971e9#discussion_r1755375409
+// ignore: unused_element
+final bool _fieldToKeepDevtoolsExtensionReachable =
+    fieldToKeepDevtoolsExtensionLibraryAlive;

packages/shared_preferences/shared_preferences/lib/src/shared_preferences_devtools_extension_data.dart

@@ -0,0 +1,138 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:convert';
+import 'dart:developer' as developer;
+
+import 'package:flutter/foundation.dart';
+
+import '../shared_preferences.dart';
+
+const String _eventPrefix = 'shared_preferences.';
+
+/// A typedef for the post event function.
+@visibleForTesting
+typedef PostEvent = void Function(
+  String eventKind,
+  Map<String, Object?> eventData,
+);
+
+/// A helper class that provides data to the DevTools extension.
+///
+/// It is only visible for testing and eval.
+@visibleForTesting
+class SharedPreferencesDevToolsExtensionData {
+  /// The default constructor for [SharedPreferencesDevToolsExtensionData].
+  ///
+  /// Accepts an optional [PostEvent] that should only be overwritten when testing.
+  const SharedPreferencesDevToolsExtensionData([
+    this._postEvent = developer.postEvent,
+  ]);
+
+  final PostEvent _postEvent;
+
+  /// Requests all legacy and async keys and post an event with the result.
+  Future<void> requestAllKeys() async {
+    final SharedPreferences legacyPrefs = await SharedPreferences.getInstance();
+    final Set<String> legacyKeys = legacyPrefs.getKeys();
+    final Set<String> asyncKeys = await SharedPreferencesAsync().getKeys();
+
+    _postEvent('${_eventPrefix}all_keys', <String, List<String>>{
+      'asyncKeys': asyncKeys.toList(),
+      'legacyKeys': legacyKeys.toList(),
+    });
+  }
+
+  /// Requests the value for a given key and posts an event with the result.
+  Future<void> requestValue(String key, bool legacy) async {
+    final Object? value;
+    if (legacy) {
+      final SharedPreferences legacyPrefs =
+          await SharedPreferences.getInstance();
+      value = legacyPrefs.get(key);
+    } else {
+      value = await SharedPreferencesAsync().getAll(allowList: <String>{
+        key
+      }).then((Map<String, Object?> map) => map.values.firstOrNull);
+    }
+
+    _postEvent('${_eventPrefix}value', <String, Object?>{
+      'value': value,
+      // It is safe to use `runtimeType` here. This code
+      // will only ever run in debug mode.
+      'kind': value.runtimeType.toString(),
+    });
+  }
+
+  /// Requests the value change for the given key and posts an empty event when finished.
+  Future<void> requestValueChange(
+    String key,
+    String serializedValue,
+    String kind,
+    bool legacy,
+  ) async {
+    final Object? value = jsonDecode(serializedValue);
+    if (legacy) {
+      final SharedPreferences legacyPrefs =
+          await SharedPreferences.getInstance();
+      // we need to check the kind because sometimes a double
+      // gets interpreted as an int. If this was not an issue
+      // we'd only need to do a simple pattern matching on value.
+      switch (kind) {
+        case 'int':
+          await legacyPrefs.setInt(key, value! as int);
+        case 'bool':
+          await legacyPrefs.setBool(key, value! as bool);
+        case 'double':
+          await legacyPrefs.setDouble(key, value! as double);
+        case 'String':
+          await legacyPrefs.setString(key, value! as String);
+        case 'List<String>':
+          await legacyPrefs.setStringList(
+            key,
+            (value! as List<Object?>).cast(),
+          );
+      }
+    } else {
+      final SharedPreferencesAsync prefs = SharedPreferencesAsync();
+      // we need to check the kind because sometimes a double
+      // gets interpreted as an int. If this was not an issue
+      // we'd only need to do a simple pattern matching on value.
+      switch (kind) {
+        case 'int':
+          await prefs.setInt(key, value! as int);
+        case 'bool':
+          await prefs.setBool(key, value! as bool);
+        case 'double':
+          await prefs.setDouble(key, value! as double);
+        case 'String':
+          await prefs.setString(key, value! as String);
+        case 'List<String>':
+          await prefs.setStringList(
+            key,
+            (value! as List<Object?>).cast(),
+          );
+      }
+    }
+    _postEvent('${_eventPrefix}change_value', <String, Object?>{});
+  }
+
+  /// Requests a key removal and posts an empty event when removed.
+  Future<void> requestRemoveKey(String key, bool legacy) async {
+    if (legacy) {
+      final SharedPreferences legacyPrefs =
+          await SharedPreferences.getInstance();
+      await legacyPrefs.remove(key);
+    } else {
+      await SharedPreferencesAsync().remove(key);
+    }
+    _postEvent('${_eventPrefix}remove', <String, Object?>{});
+  }
+}
+
+/// Include a variable to keep the library alive in web builds.
+/// It must be a `final` variable.
+/// Check this discussion for more info: https://github.com/flutter/packages/pull/6749/files/6eb1b4fdce1eba107294770d581713658ff971e9#discussion_r1755375409
+// ignore: prefer_const_declarations
+final bool fieldToKeepDevtoolsExtensionLibraryAlive = false;

packages/shared_preferences/shared_preferences/lib/src/shared_preferences_legacy.dart

@@ -8,6 +8,8 @@ import 'package:flutter/foundation.dart' show visibleForTesting;
 import 'package:shared_preferences_platform_interface/shared_preferences_platform_interface.dart';
 import 'package:shared_preferences_platform_interface/types.dart';
 
+import 'shared_preferences_devtools_extension_data.dart';
+
 /// Wraps NSUserDefaults (on iOS) and SharedPreferences (on Android), providing
 /// a persistent store for simple data.
 ///
@@ -285,3 +287,10 @@ Either update the implementation to support setPrefix, or do not call setPrefix.
     _completer = null;
   }
 }
+
+// Include an unused import to ensure this library is included
+// when running `flutter run -d chrome`.
+// Check this discussion for more info: https://github.com/flutter/packages/pull/6749/files/6eb1b4fdce1eba107294770d581713658ff971e9#discussion_r1755375409
+// ignore: unused_element
+final bool _fieldToKeepDevtoolsExtensionReachable =
+    fieldToKeepDevtoolsExtensionLibraryAlive;

packages/shared_preferences/shared_preferences/pubspec.yaml

@@ -1,9 +1,8 @@
 name: shared_preferences
-description: Flutter plugin for reading and writing simple key-value pairs.
-  Wraps NSUserDefaults on iOS and SharedPreferences on Android.
+description: Flutter plugin for reading and writing simple key-value pairs. Wraps NSUserDefaults on iOS and SharedPreferences on Android.
 repository: https://github.com/flutter/packages/tree/main/packages/shared_preferences/shared_preferences
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+shared_preferences%22
-version: 2.3.3
+version: 2.4.0
 
 environment:
   sdk: ^3.4.0
@@ -40,6 +39,7 @@ dev_dependencies:
     sdk: flutter
   integration_test:
     sdk: flutter
+  path: ^1.9.0
 
 topics:
   - persistence