[analysis_server] Trigger reanalysis when LSP TODO settings change

Previously the setting only applied to future analysis, but this triggers reanalysis immediately.

Change-Id: Ia5687e2bbf5f5a48d9659645c5b15976e712f44f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/263800
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

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

@@ -38,11 +38,24 @@ class LspClientConfiguration {
   /// Returns the global configuration for the whole workspace.
   LspGlobalClientConfiguration get global => _globalSettings;
 
+  /// Returns whether or not the provided new configuration changes any values
+  /// that would affect analysis results.
+  bool affectsAnalysisResults(LspGlobalClientConfiguration otherConfig) {
+    // Check whether TODO settings have changed.
+    final oldFlag = _globalSettings.showAllTodos;
+    final newFlag = otherConfig.showAllTodos;
+    final oldTypes = _globalSettings.showTodoTypes;
+    final newTypes = otherConfig.showTodoTypes;
+    return newFlag != oldFlag ||
+        !const SetEquality().equals(oldTypes, newTypes);
+  }
+
   /// Returns whether or not the provided new configuration changes any values
   /// that would require analysis roots to be updated.
   bool affectsAnalysisRoots(LspGlobalClientConfiguration otherConfig) {
-    return _globalSettings.analysisExcludedFolders !=
-        otherConfig.analysisExcludedFolders;
+    final oldExclusions = _globalSettings.analysisExcludedFolders;
+    final newExclusions = otherConfig.analysisExcludedFolders;
+    return !const ListEquality().equals(oldExclusions, newExclusions);
   }
 
   /// Returns config for a given resource.

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

@@ -272,6 +272,11 @@ class LspAnalysisServer extends AnalysisServer {
 
         if (clientConfiguration.affectsAnalysisRoots(oldGlobalConfig)) {
           await _refreshAnalysisRoots();
+        } else if (clientConfiguration
+            .affectsAnalysisResults(oldGlobalConfig)) {
+          // Some settings affect analysis results and require re-analysis
+          // (such as showTodos).
+          await reanalyze();
         }
       }
     }

pkg/analysis_server/test/lsp/diagnostic_test.dart

@@ -531,12 +531,24 @@ analyzer:
     // Ensure initial analysis completely finished before we continue.
     await initialAnalysis;
 
-    // Enable showTodos and update the file to ensure TODOs now come through.
-    final secondDiagnosticsUpdate = waitForDiagnostics(mainFileUri);
+    // Capture any diagnostic updates. We might get multiple, because during
+    // a reanalyze, all diagnostics are flushed (to empty) and then analysis
+    // occurs.
+    List<Diagnostic>? latestDiagnostics;
+    notificationsFromServer
+        .where((notification) =>
+            notification.method == Method.textDocument_publishDiagnostics)
+        .map((notification) => PublishDiagnosticsParams.fromJson(
+            notification.params as Map<String, Object?>))
+        .where((diagnostics) => diagnostics.uri == mainFileUri)
+        .listen((diagnostics) {
+      latestDiagnostics = diagnostics.diagnostics;
+    });
+
+    final nextAnalysis = waitForAnalysisComplete();
     await updateConfig({'showTodos': true});
-    await replaceFile(222, mainFileUri, contents);
-    final updatedDiagnostics = await secondDiagnosticsUpdate;
-    expect(updatedDiagnostics, hasLength(1));
+    await nextAnalysis;
+    expect(latestDiagnostics, hasLength(1));
   }
 
   Future<void> test_todos_specific() async {