[analysis_server] Support formatter page width from analysis_options in legacy protocol

This adds the same support previously added to LSP to the legacy protocol.

As with LSP, the value in analysis_options overrides the explicit argument (since the expectation is that the user has not specifically chosen this value for this file, but rather as a default for the project/globally).

See #56864


[analyzer] Add support for "formatter" in analysis_options + use page_width in LSP

This adds support for validation + completion for `formatter/page_width` in analysis_options, and uses this value in preference to the client-supplied value in the LSP server.

It does not yet add support for the legacy protocol, and there are a few questions in #56864 (comment).

See #56864

Change-Id: Ic2be00087f78eb62c409dbc8f558d2f24b521f78
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/388920
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: DanTup

pkg/analysis_server/doc/api.html

@@ -2321,7 +2321,9 @@ <h4>parameters:</h4><dl><dt class="field"><b>file: <a href="#type_FilePath">File
       </dd><dt class="field"><b>lineLength: int<span style="color:#999999"> (optional)</span></b></dt><dd>
 
         <p>
-          The line length to be used by the formatter.
+          The line length to be used by the formatter. This value is ignored if a
+          <tt>formatter.page_width</tt> has been configured in the relevant
+          <tt>analysis_options.yaml</tt> file.
         </p>
       </dd></dl><h4>returns:</h4><dl><dt class="field"><b>edits: List&lt;<a href="#type_SourceEdit">SourceEdit</a>&gt;</b></dt><dd>
 

pkg/analysis_server/lib/protocol/protocol_generated.dart

@@ -5830,7 +5830,9 @@ class EditFormatParams implements RequestParams {
   /// The length of the current selection in the file.
   int selectionLength;
 
-  /// The line length to be used by the formatter.
+  /// The line length to be used by the formatter. This value is ignored if a
+  /// formatter.page_width has been configured in the relevant
+  /// analysis_options.yaml file.
   int? lineLength;
 
   EditFormatParams(this.file, this.selectionOffset, this.selectionLength,

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

@@ -7,6 +7,7 @@ import 'dart:async';
 import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/handler/legacy/legacy_handler.dart';
+import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:dart_style/src/dart_formatter.dart';
 import 'package:dart_style/src/exceptions.dart';
@@ -50,10 +51,17 @@ class EditFormatHandler extends LegacyHandler {
     );
 
     var driver = server.getAnalysisDriver(file);
-    var library = await driver?.getResolvedLibrary(file);
+    var unit = await driver?.getResolvedUnit(file);
+    var (pageWidth, effectiveLanguageVersion) = switch (unit) {
+      ResolvedUnitResult() => (
+          unit.analysisOptions.formatterOptions.pageWidth,
+          unit.libraryElement2.effectiveLanguageVersion,
+        ),
+      (_) => (null, null),
+    };
     var formatter = DartFormatter(
-        pageWidth: params.lineLength,
-        languageVersion: library.effectiveLanguageVersion);
+        pageWidth: pageWidth ?? params.lineLength,
+        languageVersion: effectiveLanguageVersion);
     SourceCode formattedResult;
     try {
       formattedResult = formatter.formatSource(code);

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

@@ -10,6 +10,7 @@ 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/dart/element/element2.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';
@@ -100,6 +101,14 @@ abstract class LegacyHandler {
   }
 }
 
+extension LibraryElement2Extension on LibraryElement2 {
+  // TODO(dantup): Remove this once we can use `languageVersion.effective`
+  //  in element-model-migrated files without triggering the lint.
+  Version get effectiveLanguageVersion {
+    return languageVersion.effective;
+  }
+}
+
 extension SomeResolvedLibraryResultExtension on SomeResolvedLibraryResult? {
   Version get effectiveLanguageVersion {
     var self = this;

pkg/analysis_server/test/edit/format_test.dart

@@ -23,7 +23,49 @@ class FormatTest extends PubPackageAnalysisServerTest {
     await setRoots(included: [workspaceRootPath], excluded: []);
   }
 
-  Future<void> test_format_longLine() async {
+  Future<void> test_format_longLine_analysisOptions() async {
+    writeTestPackageAnalysisOptionsFile(r'''
+formatter:
+  page_width: 100
+''');
+    var content = '''
+fun(firstParam, secondParam, thirdParam, fourthParam) {
+  if (firstParam.noNull && secondParam.noNull && thirdParam.noNull && fourthParam.noNull) {}
+}
+''';
+    addTestFile(content);
+    await waitForTasksFinished();
+    var formatResult = await _formatAt(0, 3);
+
+    expect(formatResult.edits, isNotNull);
+    expect(formatResult.edits, hasLength(0));
+
+    expect(formatResult.selectionOffset, equals(0));
+    expect(formatResult.selectionLength, equals(3));
+  }
+
+  Future<void> test_format_longLine_analysisOptions_overridesParameter() async {
+    writeTestPackageAnalysisOptionsFile(r'''
+formatter:
+  page_width: 100
+''');
+    var content = '''
+fun(firstParam, secondParam, thirdParam, fourthParam) {
+  if (firstParam.noNull && secondParam.noNull && thirdParam.noNull && fourthParam.noNull) {}
+}
+''';
+    addTestFile(content);
+    await waitForTasksFinished();
+    var formatResult = await _formatAt(0, 3, lineLength: 50);
+
+    expect(formatResult.edits, isNotNull);
+    expect(formatResult.edits, hasLength(0));
+
+    expect(formatResult.selectionOffset, equals(0));
+    expect(formatResult.selectionLength, equals(3));
+  }
+
+  Future<void> test_format_longLine_parameter() async {
     var content = '''
 fun(firstParam, secondParam, thirdParam, fourthParam) {
   if (firstParam.noNull && secondParam.noNull && thirdParam.noNull && fourthParam.noNull) {}

pkg/analysis_server/test/integration/support/integration_test_methods.dart

@@ -1566,7 +1566,9 @@ abstract class IntegrationTest {
   ///
   /// lineLength: int (optional)
   ///
-  ///   The line length to be used by the formatter.
+  ///   The line length to be used by the formatter. This value is ignored if a
+  ///   formatter.page_width has been configured in the relevant
+  ///   analysis_options.yaml file.
   ///
   /// Returns
   ///

pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java

@@ -511,7 +511,8 @@ public interface AnalysisServer {
    * @param file The file containing the code to be formatted.
    * @param selectionOffset The offset of the current selection in the file.
    * @param selectionLength The length of the current selection in the file.
-   * @param lineLength The line length to be used by the formatter.
+   * @param lineLength The line length to be used by the formatter. This value is ignored if a
+   *        formatter.page_width has been configured in the relevant analysis_options.yaml file.
    */
   public void edit_format(String file, int selectionOffset, int selectionLength, int lineLength, FormatConsumer consumer);
 

pkg/analysis_server/tool/spec/spec_input.html

@@ -2186,7 +2186,9 @@ <h4>Options</h4>
       <field name="lineLength" optional="true">
         <ref>int</ref>
         <p>
-          The line length to be used by the formatter.
+          The line length to be used by the formatter. This value is ignored if a
+          <tt>formatter.page_width</tt> has been configured in the relevant
+          <tt>analysis_options.yaml</tt> file.
         </p>
       </field>
     </params>

pkg/analysis_server_client/lib/src/protocol/protocol_generated.dart

@@ -5253,7 +5253,9 @@ class EditFormatParams implements RequestParams {
   /// The length of the current selection in the file.
   int selectionLength;
 
-  /// The line length to be used by the formatter.
+  /// The line length to be used by the formatter. This value is ignored if a
+  /// formatter.page_width has been configured in the relevant
+  /// analysis_options.yaml file.
   int? lineLength;
 
   EditFormatParams(this.file, this.selectionOffset, this.selectionLength,