[analyzer] Ensure parseFileSync() flushes pending file changes

Fixes #57120
Fixes dart-lang/dart-pad#3092

Change-Id: I803cdc19702bcd357cdafde3176ecad246495182
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/396003
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: DanTup

pkg/analysis_server/test/edit/format_test.dart

@@ -2,7 +2,9 @@
 // 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/protocol/protocol_generated.dart';
+import 'dart:async';
+
+import 'package:analysis_server/src/protocol_server.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -23,6 +25,37 @@ class FormatTest extends PubPackageAnalysisServerTest {
     await setRoots(included: [workspaceRootPath], excluded: []);
   }
 
+  /// Verify that an overlay change is reflected in a format request that
+  /// is sent immediately without waiting.
+  ///
+  /// https://github.com/dart-lang/sdk/issues/57120
+  Future<void> test_format_immediatelyAfterOverlayChange() async {
+    var initialContentNeedsFormatting = 'void main() {                       }';
+    var updatedContentNeedsNoFormatting =
+        "void main() {\n  print('hello world');\n}\n";
+
+    // Set the initial content to something that will produce format edits.
+    await handleSuccessfulRequest(
+      AnalysisUpdateContentParams({
+        testFile.path: AddContentOverlay(initialContentNeedsFormatting),
+      }).toRequest('1', clientUriConverter: server.uriConverter),
+    );
+    // Update the content to something that will not produce edits, but do not
+    // await, because we are testing that the server is consistent even if it
+    // doesn't have time to handle the change.
+    unawaited(
+      handleSuccessfulRequest(
+        AnalysisUpdateContentParams({
+          testFile.path: AddContentOverlay(updatedContentNeedsNoFormatting),
+        }).toRequest('2', clientUriConverter: server.uriConverter),
+      ),
+    );
+    var formatResult = await _formatAt(0, 0);
+
+    // Expect no edits, because the last overlay was already formatted.
+    expect(formatResult.edits, hasLength(0));
+  }
+
   Future<void> test_format_longLine_analysisOptions() async {
     writeTestPackageAnalysisOptionsFile(r'''
 formatter:

pkg/analyzer/lib/src/dart/analysis/driver.dart

@@ -1161,6 +1161,8 @@ class AnalysisDriver {
       return InvalidPathResult();
     }
 
+    _applyPendingFileChanges();
+
     var file = _fsState.getFileForPath(path);
     RecordingErrorListener listener = RecordingErrorListener();
     CompilationUnit unit = file.parse(

pkg/analyzer/test/src/dart/analysis/driver_test.dart

@@ -3921,6 +3921,25 @@ import 'b.dart';
     ]);
   }
 
+  test_parseFileSync_appliesPendingFileChanges() async {
+    var initialContent = 'initial content';
+    var updatedContent = 'updated content';
+    var a = newFile('$testPackageLibPath/a.dart', initialContent);
+
+    // Check initial content.
+    var driver = driverFor(testFile);
+    var parsed = driver.parseFileSync(a.path) as ParsedUnitResult;
+    expect(parsed.content, initialContent);
+
+    // Update the file.
+    newFile(a.path, updatedContent);
+    driver.changeFile(a.path);
+
+    // Expect parseFileSync to return the updated content.
+    parsed = driver.parseFileSync(a.path) as ParsedUnitResult;
+    expect(parsed.content, updatedContent);
+  }
+
   test_parseFileSync_changedFile() async {
     var a = newFile('$testPackageLibPath/a.dart', r'''
 ''');
@@ -3990,14 +4009,6 @@ class A {}
     // Notify the driver that `a` was changed.
     driver.changeFile2(a);
 
-    // Pending changes are no applied yes, so `a` is empty.
-    {
-      var result = driver.parseFileSync2(a) as ParsedUnitResult;
-      assertParsedNodeText(result.unit, r'''
-CompilationUnit
-''');
-    }
-
     // The pending change to `a` declares `A`.
     // So, `b` does not have errors anymore.
     collector.getResolvedUnit('B2', b);