(new) formatter language version-aware migrations

(Testing to follow.)

See: #56685




Change-Id: I9da0e3868cd3c873c41e8a19a77fad58b9b8dea0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/386901
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Phil Quitslund <pquitslund@google.com>

Author: pq

pkg/analysis_server/lib/src/g3/utilities.dart

@@ -16,12 +16,13 @@ import 'package:analyzer/src/dart/scanner/scanner.dart';
 import 'package:analyzer/src/generated/parser.dart' as p;
 import 'package:analyzer/src/string_source.dart';
 import 'package:dart_style/dart_style.dart';
+import 'package:pub_semver/pub_semver.dart';
 
 /// Return a formatted string if successful, throws a [FormatterException] if
-/// unable to format. Takes a string as input.
-String format(String content) {
+/// unable to format. Takes a string as input and an optional [languageVersion].
+String format(String content, {Version? languageVersion}) {
   var code = SourceCode(content);
-  var formatter = DartFormatter();
+  var formatter = DartFormatter(languageVersion: languageVersion);
   SourceCode formattedResult;
   formattedResult = formatter.formatSource(code);
   return formattedResult.text;

pkg/analysis_server/lib/src/handler/legacy/edit_format.dart

@@ -48,7 +48,12 @@ class EditFormatHandler extends LegacyHandler {
       selectionStart: start,
       selectionLength: length,
     );
-    var formatter = DartFormatter(pageWidth: params.lineLength);
+
+    var driver = server.getAnalysisDriver(file);
+    var library = await driver?.getResolvedLibrary(file);
+    var formatter = DartFormatter(
+        pageWidth: params.lineLength,
+        languageVersion: library.effectiveLanguageVersion);
     SourceCode formattedResult;
     try {
       formattedResult = formatter.formatSource(code);

pkg/analysis_server/lib/src/handler/legacy/edit_format_if_enabled.dart

@@ -13,6 +13,7 @@ import 'package:analyzer/src/util/file_paths.dart' as file_paths;
 import 'package:dart_style/src/dart_formatter.dart';
 import 'package:dart_style/src/exceptions.dart';
 import 'package:dart_style/src/source_code.dart';
+import 'package:pub_semver/pub_semver.dart';
 
 /// The handler for the `edit.formatIfEnabled` request.
 class EditFormatIfEnabledHandler extends LegacyHandler {
@@ -21,17 +22,18 @@ class EditFormatIfEnabledHandler extends LegacyHandler {
   EditFormatIfEnabledHandler(
       super.server, super.request, super.cancellationToken, super.performance);
 
-  /// Format the given [file].
+  /// Format the given [file] with the given [languageVersion].
   ///
   /// Throws a [FileSystemException] if the file doesn't exist or can't be read.
   /// Throws a [FormatterException] if the code could not be formatted.
-  List<SourceEdit> formatFile(File file) {
+  List<SourceEdit> formatFile(File file, {Version? languageVersion}) {
     // TODO(brianwilkerson): Move this to a superclass when `edit.format` is
     //  implemented by a handler class so the code can be shared.
     var originalContent = file.readAsStringSync();
     var code = SourceCode(originalContent);
 
-    var formatter = DartFormatter();
+    var formatter = DartFormatter(languageVersion: languageVersion);
+
     var formatResult = formatter.formatSource(code);
     var formattedContent = formatResult.text;
 
@@ -56,16 +58,16 @@ class EditFormatIfEnabledHandler extends LegacyHandler {
     );
     var sourceFileEdits = <SourceFileEdit>[];
     for (var context in collection.contexts) {
-      _formatInContext(context, sourceFileEdits);
+      await _formatInContext(context, sourceFileEdits);
     }
     sendResult(EditFormatIfEnabledResult(sourceFileEdits));
   }
 
   /// Format all of the Dart files in the given [context] whose associated
   /// `codeStyleOptions` enable formatting, adding the edits to the list of
   /// [sourceFileEdits].
-  void _formatInContext(DriverBasedAnalysisContext context,
-      List<SourceFileEdit> sourceFileEdits) {
+  Future<void> _formatInContext(DriverBasedAnalysisContext context,
+      List<SourceFileEdit> sourceFileEdits) async {
     var pathContext = context.resourceProvider.pathContext;
     for (var filePath in context.contextRoot.analyzedFiles()) {
       // Skip anything but .dart files.
@@ -80,7 +82,10 @@ class EditFormatIfEnabledHandler extends LegacyHandler {
       var options = context.getAnalysisOptionsForFile(resource);
       if (options.codeStyleOptions.useFormatter) {
         try {
-          var sourceEdits = formatFile(resource);
+          var library = await context.driver.getResolvedLibrary(filePath);
+          var languageVersion = library.effectiveLanguageVersion;
+          var sourceEdits =
+              formatFile(resource, languageVersion: languageVersion);
           if (sourceEdits.isNotEmpty) {
             sourceFileEdits
                 .add(SourceFileEdit(filePath, 0, edits: sourceEdits));

pkg/analysis_server/lib/src/handler/legacy/legacy_handler.dart

@@ -9,10 +9,12 @@ import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/legacy_analysis_server.dart';
 import 'package:analysis_server/src/protocol/protocol_internal.dart';
+import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/dart/error/syntactic_errors.g.dart';
 import 'package:analyzer/src/util/performance/operation_performance.dart';
 import 'package:analyzer/src/utilities/cancellation.dart';
+import 'package:pub_semver/pub_semver.dart';
 
 /// A request handler for the completion domain.
 abstract class CompletionHandler extends LegacyHandler {
@@ -96,3 +98,13 @@ abstract class LegacyHandler {
         params.toNotification(clientUriConverter: server.uriConverter));
   }
 }
+
+extension SomeResolvedLibraryResultExtension on SomeResolvedLibraryResult? {
+  Version? get effectiveLanguageVersion {
+    var self = this;
+    if (self is ResolvedLibraryResult) {
+      return self.element.languageVersion.effective;
+    }
+    return null;
+  }
+}

pkg/analysis_server/lib/src/lsp/source_edits.dart

@@ -91,7 +91,11 @@ ErrorOr<List<TextEdit>?> generateEditsForFormatting(
     // Create a new formatter on every request because it may contain state that
     // affects repeated formats.
     // https://github.com/dart-lang/dart_style/issues/1337
-    formattedResult = DartFormatter(pageWidth: lineLength).formatSource(code);
+    var languageVersion =
+        result.unit.declaredElement?.library.languageVersion.effective;
+    formattedResult =
+        DartFormatter(pageWidth: lineLength, languageVersion: languageVersion)
+            .formatSource(code);
   } on FormatterException {
     // If the document fails to parse, just return no edits to avoid the
     // use seeing edits on every save with invalid code (if LSP gains the

pkg/analysis_server/pubspec.yaml

@@ -24,6 +24,7 @@ dependencies:
   memory_usage: any
   meta: any
   path: any
+  pub_semver: any
   stream_channel: any
   telemetry: any
   test: any

pkg/analysis_server/test/integration/edit/format_test.dart

@@ -10,6 +10,7 @@ import '../support/integration_tests.dart';
 void main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(FormatTest);
+    defineReflectiveTests(LanguageVersionSpecificFormatTest);
   });
 }
 
@@ -76,3 +77,46 @@ class Class1 {
     }
   }
 }
+
+@reflectiveTest
+class LanguageVersionSpecificFormatTest
+    extends AbstractAnalysisServerIntegrationTest {
+  Future<String> createTestFile(String text) async {
+    var pathname = sourcePath('test.dart');
+    writeFile(pathname, text);
+    await standardAnalysisSetup();
+    return pathname;
+  }
+
+  Future<void> test_format_short() async {
+    var path = await createTestFile('''
+// @dart = 3.5
+
+void f({String? argument1, String? argument2}) {}
+
+void g() {
+  f(argument1: 'An argument', argument2: 'Another argument');
+}
+''');
+
+    var result = await sendEditFormat(path, 0, 0);
+
+    // No change in short style.
+    expect(result.edits, isEmpty);
+  }
+
+  @FailingTest(issue: 'https://github.com/dart-lang/sdk/issues/56685')
+  Future<void> test_format_tall() async {
+    var path = await createTestFile('''
+void f({String? argument1, String? argument2}) {}
+
+void g() {
+  f(argument1: 'An argument', argument2: 'Another argument');
+}
+''');
+
+    var result = await sendEditFormat(path, 0, 0);
+    expect(result.edits, isNotEmpty);
+    // TODO(pq): update expectations when formatter is complete
+  }
+}

pkg/analysis_server/test/lsp/source_edits_test.dart

@@ -356,6 +356,56 @@ Delete 1:18-2:1
     );
   }
 
+  Future<void> test_minimalEdits_formatting_shortStyle() async {
+    const startContent = '''
+// @dart = 3.5
+
+void f({String argument1, String argument2}) {}
+
+void g() {
+  f(argument1: 'An argument', argument2: 'Another argument');
+}
+''';
+    const endContent = '''
+// @dart = 3.5
+
+void f({String argument1, String argument2}) {}
+
+void g() {
+  f(argument1: 'An argument', argument2: 'Another argument');
+}
+''';
+    const expectedEdits = '';
+
+    await _assertMinimalEdits(startContent, endContent, expectedEdits);
+  }
+
+  @FailingTest(issue: 'https://github.com/dart-lang/sdk/issues/56685')
+  Future<void> test_minimalEdits_formatting_tallStyle() async {
+    const startContent = '''
+void f({String? argument1, String? argument2}) {}
+
+void g() {
+  f(argument1: 'An argument', argument2: 'Another argument');
+}
+''';
+    const endContent = '''
+void f({String? argument1, String? argument2}) {}
+
+void g() {
+  f(argument1: 'An argument',
+    argument2: 'Another argument',
+  );
+}
+''';
+    const expectedEdits = r'''
+Insert "\n    " at 4:31
+Insert ",\n" at 4:60
+''';
+
+    await _assertMinimalEdits(startContent, endContent, expectedEdits);
+  }
+
   Future<void> test_minimalEdits_gt_2_combined() async {
     const startContent = '''
 List<