[cronet_http] ✨ Add Cronet embedded tool

pkgs/cronet_http/README_EMBEDDED.md

@@ -0,0 +1,12 @@
+An Android Flutter plugin that provides access to the
+[Cronet](https://developer.android.com/guide/topics/connectivity/cronet/reference/org/chromium/net/package-summary)
+HTTP client.
+
+This package is identical to [`package:cronet_http`](https://pub.dev/packages/cronet_http)
+except that it embeds
+[Cronet](https://developer.android.com/guide/topics/connectivity/cronet/reference/org/chromium/net/package-summary)
+rather than using the version included with
+[Google Play Services](https://developers.google.com/android/guides/overview).
+This increases the uncompressed size of the application by approximately 8MB.
+
+See more details about cronet_http at: https://pub.dev/packages/cronet_http.

pkgs/cronet_http/pubspec.yaml

@@ -16,6 +16,8 @@ dependencies:
 dev_dependencies:
   lints: ^1.0.0
   pigeon: ^3.2.3
+  xml: ^6.1.0
+  yaml_edit: ^2.0.3
 
 flutter:
   plugin:

pkgs/cronet_http/tool/prepare_for_embedded.dart

@@ -0,0 +1,104 @@
+// Copyright (c) 2022, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// The cronet_http directory is used to produce two packages:
+/// - `cronet_http`, which uses the Google Play Services version of Cronet.
+/// - `cronet_http_embedded`, which embeds Cronet.
+///
+/// The default configuration of this code is to use the
+/// Google Play Services version of Cronet.
+///
+/// The script transforms the configuration into one that embeds Cronet by:
+/// 1. Modifying the Gradle build file to reference the embedded Cronet.
+/// 2. Modifying the *name* and *description* in `pubspec.yaml`.
+/// 3. Replacing `README.md` with `README_EMBEDDED.md`.
+///
+/// After running this script, `flutter pub publish`
+/// can be run to update package:cronet_http_embedded.
+///
+/// NOTE: This script modifies the above files in place.
+
+import 'dart:io';
+
+import 'package:http/http.dart' as http;
+import 'package:xml/xml.dart';
+import 'package:yaml_edit/yaml_edit.dart';
+
+late final Directory _packageDirectory;
+
+const _gmsDependencyName = 'com.google.android.gms:play-services-cronet';
+const _embeddedDependencyName = 'org.chromium.net:cronet-embedded';
+const _packageName = 'cronet_http_embedded';
+const _packageDescription = 'An Android Flutter plugin that '
+    'provides access to the Cronet HTTP client. '
+    'Identical to package:cronet_http except that it embeds Cronet '
+    'rather than relying on Google Play Services.';
+final _cronetVersionUri = Uri.https(
+  'dl.google.com',
+  'android/maven2/org/chromium/net/group-index.xml',
+);
+
+void main() async {
+  if (Directory.current.path.endsWith('tool')) {
+    _packageDirectory = Directory.current.parent;
+  } else {
+    _packageDirectory = Directory.current;
+  }
+
+  final latestVersion = await _getLatestCronetVersion();
+  updateCronetDependency(latestVersion);
+  updatePubSpec();
+  updateReadme();
+}
+
+Future<String> _getLatestCronetVersion() async {
+  final response = await http.get(_cronetVersionUri);
+  final parsedXml = XmlDocument.parse(response.body);
+  final embeddedNode = parsedXml.children
+      .singleWhere((e) => e is XmlElement)
+      .children
+      .singleWhere((e) => e is XmlElement && e.name.local == 'cronet-embedded');
+  final stableVersionReg = RegExp(r'^\d+.\d+.\d+$');
+  final versions = embeddedNode.attributes
+      .singleWhere((e) => e.name.local == 'versions')
+      .value
+      .split(',')
+      .where((e) => stableVersionReg.stringMatch(e) == e);
+  return versions.last;
+}
+
+/// Update android/build.gradle
+void updateCronetDependency(String latestVersion) {
+  final fBuildGradle = File('${_packageDirectory.path}/android/build.gradle');
+  final gradleContent = fBuildGradle.readAsStringSync();
+  final implementationRegExp = RegExp(
+    '^\\s*implementation [\'"]'
+    '$_gmsDependencyName'
+    ':\\d+.\\d+.\\d+[\'"]',
+    multiLine: true,
+  );
+  final newImplementation = '$_embeddedDependencyName:$latestVersion';
+  print('Patching $newImplementation');
+  final newGradleContent = gradleContent.replaceAll(
+    implementationRegExp,
+    '    implementation $newImplementation',
+  );
+  fBuildGradle.writeAsStringSync(newGradleContent);
+}
+
+/// Update pubspec.yaml
+void updatePubSpec() {
+  final fPubspec = File('${_packageDirectory.path}/pubspec.yaml');
+  final yamlEditor = YamlEditor(fPubspec.readAsStringSync())
+    ..update(['name'], _packageName)
+    ..update(['description'], _packageDescription);
+  fPubspec.writeAsStringSync(yamlEditor.toString());
+}
+
+/// Move README_EMBEDDED.md to replace README.md
+void updateReadme() {
+  File('${_packageDirectory.path}/README.md').deleteSync();
+  File('${_packageDirectory.path}/README_EMBEDDED.md')
+      .renameSync('${_packageDirectory.path}/README.md');
+}

pkgs/cronet_http/run_pigeon.sh → pkgs/cronet_http/tool/run_pigeon.sh

@@ -1,6 +1,7 @@
 #!/bin/sh
 
 # Generate the platform messages used by cronet_http.
+cd ../
 
 flutter pub run pigeon \
   --input pigeons/messages.dart \