DAS plugins: Add plugin package generator

This generator will be used create shared plugin package entrypoints from
plugin configurations.

Work towards https://github.com/dart-lang/sdk/issues/53402

Change-Id: If5c6aeb7bc7845311975928fba1cb9c8d273423c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/384681
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>

pkg/analysis_server/lib/src/plugin/README.md

@@ -0,0 +1,3 @@
+This directory contains sources for the "prototype" plugin system introduced
+circa 2017, which is being replaced by the "new" plugin system introduced
+circa 2024. The sources for the "new" plugin system are located in `../plugin2`.

pkg/analysis_server/lib/src/plugin2/README.md

@@ -0,0 +1,8 @@
+This directory contains sources for the "new" plugin system introduced circa
+2024, which is the replacement for the "prototype" plugin system introduced
+circa 2017. The sources for the "prototype" plugin system are located in
+`../plugin`.
+
+The "new" plugin system is partially based on the "prototype" plugin system. As
+the "prototype" plugin system becomes deprecated and unsupported, any features
+that the "new" plugin system relies on can be migrated to this directory.

pkg/analysis_server/lib/src/plugin2/generator.dart

@@ -0,0 +1,79 @@
+// Copyright (c) 2024, 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.
+
+/// This class can generate various files to make up the shared plugin package.
+class PluginPackageGenerator {
+  /// The plugin configuration, a map of plugin names to each plugin's
+  /// configuration.
+  ///
+  /// This typically stems from plugin configuration in an analysis options
+  /// file.
+  final Map<String, Object> _pluginConfiguration;
+
+  PluginPackageGenerator(this._pluginConfiguration);
+
+  /// Generates the Dart entrpoint file which is to be spawned in a Dart
+  /// isolate by the analysis server.
+  String generateEntrypoint() {
+    var imports = [
+      "'package:analysis_server_plugin/src/plugin_server.dart'",
+      "'package:analyzer/file_system/physical_file_system.dart'",
+      "'package:analyzer_plugin/starter.dart'",
+      for (var name in _pluginConfiguration.keys)
+        "'package:$name/main.dart' as $name",
+    ];
+
+    var buffer = StringBuffer("import 'dart:isolate';");
+    for (var import in imports..sort()) {
+      buffer.writeln('import $import;');
+    }
+
+    buffer.write('''
+Future<void> main(List<String> args, SendPort sendPort) async {
+  var pluginServer = PluginServer(
+    resourceProvider: PhysicalResourceProvider.INSTANCE,
+    plugins: [
+''');
+    // TODO(srawlins): Format with the formatter, for readability.
+    for (var name in _pluginConfiguration.keys) {
+      buffer.writeln('      $name.plugin,');
+    }
+    buffer.write('''
+    ],
+  );
+  await startPlugin();
+  ServerPluginStarter(wrangler).start(sendPort);
+}
+''');
+
+    return buffer.toString();
+  }
+
+  /// Generates a pubspec file which spells out where to retreive plugin package
+  /// sources.
+  String generatePubspec() {
+    var buffer = StringBuffer();
+    buffer.write('''
+name: plugin_entrypoint
+version: 0.0.1
+dependencies:
+''');
+
+    for (var MapEntry(key: name, value: configuration)
+        in _pluginConfiguration.entries) {
+      switch (configuration) {
+        case String():
+          buffer.writeln('  $name: $configuration');
+        case Map<String, Object>():
+          if (configuration case {'path': String pathValue}) {
+            buffer.writeln('  $name:\n    path: $pathValue');
+          } else if (configuration case {'git': String gitValue}) {
+            buffer.writeln('  $name:\n    git: $gitValue');
+          }
+      }
+    }
+
+    return buffer.toString();
+  }
+}

pkg/analysis_server/test/src/plugin/test_all.dart

@@ -23,5 +23,5 @@ void main() {
     result_collector_test.main();
     result_converter_test.main();
     result_merger_test.main();
-  });
+  }, name: 'plugin');
 }

pkg/analysis_server/test/src/plugin2/README.md

@@ -0,0 +1,5 @@
+This directory contains tests for the "new" plugin system introduced circa 2024,
+which is the replacement for the "prototype" plugin system introduced circa
+2017. The tests for the "prototype" plugin are located in `../plugin`.
+Eventually, all tests in `../plugin` which test some equivalent behavior in the
+"new" plugin system should be migrated here.

pkg/analysis_server/test/src/plugin2/generator_test.dart

@@ -0,0 +1,92 @@
+// Copyright (c) 2024, 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.
+
+import 'package:analysis_server/src/plugin2/generator.dart';
+import 'package:test/test.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+void main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(GeneratorTest);
+  });
+}
+
+@reflectiveTest
+class GeneratorTest {
+  void test_entrypointImportsPluginEntrypoints() {
+    var pluginPackageGenerator = PluginPackageGenerator({
+      'no_bools': '^1.0.0',
+      'no_ints': '^1.2.0',
+    });
+    expect(
+      pluginPackageGenerator.generateEntrypoint(),
+      contains('''
+import 'package:no_bools/main.dart' as no_bools;
+import 'package:no_ints/main.dart' as no_ints;
+'''),
+    );
+  }
+
+  void test_entrypointListsPluginInstances() {
+    var pluginPackageGenerator = PluginPackageGenerator({
+      'no_bools': '^1.0.0',
+      'no_ints': '^1.2.0',
+    });
+    expect(
+      pluginPackageGenerator.generateEntrypoint(),
+      contains('''
+    plugins: [
+      no_bools.plugin,
+      no_ints.plugin,
+    ],
+'''),
+    );
+  }
+
+  void test_pubspecContainsGitDependencies() {
+    var pluginPackageGenerator = PluginPackageGenerator({
+      'no_bools': {'git': 'https://example.com/example.git'},
+    });
+    expect(
+      pluginPackageGenerator.generatePubspec(),
+      contains('''
+dependencies:
+  no_bools:
+    git: https://example.com/example.git
+'''),
+    );
+  }
+
+  void test_pubspecContainsPathDependencies() {
+    var pluginPackageGenerator = PluginPackageGenerator({
+      'no_bools': {'path': '../no_bools_plugin'},
+      'no_ints': {'path': 'tools/no_ints_plugin'},
+    });
+    expect(
+      pluginPackageGenerator.generatePubspec(),
+      contains('''
+dependencies:
+  no_bools:
+    path: ../no_bools_plugin
+  no_ints:
+    path: tools/no_ints_plugin
+'''),
+    );
+  }
+
+  void test_pubspecContainsVersionedDependencies() {
+    var pluginPackageGenerator = PluginPackageGenerator({
+      'no_bools': '^1.0.0',
+      'no_ints': '^1.2.0',
+    });
+    expect(
+      pluginPackageGenerator.generatePubspec(),
+      contains('''
+dependencies:
+  no_bools: ^1.0.0
+  no_ints: ^1.2.0
+'''),
+    );
+  }
+}

pkg/analysis_server/test/src/plugin2/test_all.dart

@@ -0,0 +1,13 @@
+// Copyright (c) 2024, 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.
+
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import 'generator_test.dart' as generator_test;
+
+void main() {
+  defineReflectiveSuite(() {
+    generator_test.main();
+  }, name: 'plugin2');
+}

pkg/analysis_server/test/src/test_all.dart

@@ -12,6 +12,7 @@ import 'flutter/test_all.dart' as flutter;
 import 'g3/test_all.dart' as g3;
 import 'lsp/test_all.dart' as lsp;
 import 'plugin/test_all.dart' as plugin;
+import 'plugin2/test_all.dart' as plugin2;
 import 'server/test_all.dart' as server;
 import 'services/test_all.dart' as services;
 import 'utilities/test_all.dart' as utilities;
@@ -26,6 +27,7 @@ void main() {
     g3.main();
     lsp.main();
     plugin.main();
+    plugin2.main();
     server.main();
     services.main();
     utilities.main();