Update DeclarationsTracker when a context options change.

E.g. when .packages changes, we want to re-scan the context for new
available libraries. We also don't want to discard all context, and
resend everything.

R=brianwilkerson@google.com

Bug: https://github.com/Dart-Code/Dart-Code/issues/1723
Change-Id: I19ee71c1d021fb9bcda9d02d86b7cbb078704aa7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103320
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analysis_server/lib/src/analysis_server.dart

@@ -891,6 +891,11 @@ class ServerContextManagerCallbacks extends ContextManagerCallbacks {
     analysisServer._onAnalysisSetChangedController.add(null);
   }
 
+  @override
+  void analysisOptionsUpdated(nd.AnalysisDriver driver) {
+    analysisServer.updateContextInDeclarationsTracker(driver);
+  }
+
   @override
   void applyChangesToContext(Folder contextFolder, ChangeSet changeSet) {
     nd.AnalysisDriver analysisDriver = analysisServer.driverMap[contextFolder];

pkg/analysis_server/lib/src/analysis_server_abstract.dart

@@ -291,4 +291,9 @@ abstract class AbstractAnalysisServer {
     declarationsTracker?.changeFile(path);
     analysisDriverScheduler.notify(null);
   }
+
+  void updateContextInDeclarationsTracker(nd.AnalysisDriver driver) {
+    declarationsTracker?.discardContext(driver.analysisContext);
+    declarationsTracker?.addContext(driver.analysisContext);
+  }
 }

pkg/analysis_server/lib/src/context_manager.dart

@@ -354,6 +354,11 @@ abstract class ContextManagerCallbacks {
    */
   void afterWatchEvent(WatchEvent event);
 
+  /**
+   * Called when analysis options or URI resolution in the [driver] are changed.
+   */
+  void analysisOptionsUpdated(AnalysisDriver driver);
+
   /**
    * Called when the set of files associated with a context have changed (or
    * some of those files have been modified).  [changeSet] is the set of
@@ -1630,6 +1635,7 @@ class ContextManagerImpl implements ContextManager {
         contextRoot: driver.contextRoot);
     SourceFactory factory = builder.createSourceFactory(contextRoot, options);
     driver.configure(analysisOptions: options, sourceFactory: factory);
+    callbacks.analysisOptionsUpdated(driver);
   }
 
   void _updateContextPackageUriResolver(Folder contextFolder) {

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

@@ -88,9 +88,6 @@ class LspAnalysisServer extends AbstractAnalysisServer {
    */
   RefactoringWorkspace _refactoringWorkspace;
 
-  RefactoringWorkspace get refactoringWorkspace => _refactoringWorkspace ??=
-      new RefactoringWorkspace(driverMap.values, searchEngine);
-
   /**
    * The versions of each document known to the server (keyed by path), used to
    * send back to the client for server-initiated edits so that the client can
@@ -199,6 +196,9 @@ class LspAnalysisServer extends AbstractAnalysisServer {
 
   Future<void> get exited => channel.closed;
 
+  RefactoringWorkspace get refactoringWorkspace => _refactoringWorkspace ??=
+      new RefactoringWorkspace(driverMap.values, searchEngine);
+
   addPriorityFile(String path) {
     final didAdd = priorityFiles.add(path);
     assert(didAdd);
@@ -328,6 +328,28 @@ class LspAnalysisServer extends AbstractAnalysisServer {
     ));
   }
 
+  /// Logs an exception by sending it to the client (window/logMessage) and
+  /// recording it in a buffer on the server for diagnostics.
+  void logException(String message, exception, stackTrace) {
+    if (exception is CaughtException) {
+      stackTrace ??= exception.stackTrace;
+    }
+
+    final fullError = stackTrace == null ? message : '$message\n$stackTrace';
+
+    // Log the full message since showMessage above may be truncated or formatted
+    // badly (eg. VS Code takes the newlines out).
+    logErrorToClient(fullError);
+
+    // remember the last few exceptions
+    exceptions.add(new ServerException(
+      message,
+      exception,
+      stackTrace is StackTrace ? stackTrace : null,
+      false,
+    ));
+  }
+
   void publishDiagnostics(String path, List<Diagnostic> errors) {
     final params =
         new PublishDiagnosticsParams(Uri.file(path).toString(), errors);
@@ -416,28 +438,6 @@ class LspAnalysisServer extends AbstractAnalysisServer {
     logException(message, exception, stackTrace);
   }
 
-  /// Logs an exception by sending it to the client (window/logMessage) and
-  /// recording it in a buffer on the server for diagnostics.
-  void logException(String message, exception, stackTrace) {
-    if (exception is CaughtException) {
-      stackTrace ??= exception.stackTrace;
-    }
-
-    final fullError = stackTrace == null ? message : '$message\n$stackTrace';
-
-    // Log the full message since showMessage above may be truncated or formatted
-    // badly (eg. VS Code takes the newlines out).
-    logErrorToClient(fullError);
-
-    // remember the last few exceptions
-    exceptions.add(new ServerException(
-      message,
-      exception,
-      stackTrace is StackTrace ? stackTrace : null,
-      false,
-    ));
-  }
-
   /// Send status notification to the client. The state of analysis is given by
   /// the [status] information.
   void sendStatusNotification(nd.AnalysisStatus status) {
@@ -575,6 +575,11 @@ class LspServerContextManagerCallbacks extends ContextManagerCallbacks {
     // TODO: implement afterWatchEvent
   }
 
+  @override
+  void analysisOptionsUpdated(nd.AnalysisDriver driver) {
+    // TODO: implement analysisOptionsUpdated
+  }
+
   @override
   void applyChangesToContext(Folder contextFolder, ChangeSet changeSet) {
     nd.AnalysisDriver analysisDriver = analysisServer.driverMap[contextFolder];

pkg/analysis_server/test/context_manager_test.dart

@@ -2518,6 +2518,9 @@ class TestContextManagerCallbacks extends ContextManagerCallbacks {
   @override
   void afterWatchEvent(WatchEvent event) {}
 
+  @override
+  void analysisOptionsUpdated(AnalysisDriver driver) {}
+
   @override
   void applyChangesToContext(Folder contextFolder, ChangeSet changeSet) {
     AnalysisDriver driver = driverMap[contextFolder.path];

pkg/analyzer/lib/src/services/available_declarations.dart

@@ -474,6 +474,12 @@ class DeclarationsTracker {
     _changedPaths.add(path);
   }
 
+  /// Discard the [analysisContext], but don't discard any libraries that it
+  /// might have in its dependencies.
+  void discardContext(AnalysisContext analysisContext) {
+    _contexts.remove(analysisContext);
+  }
+
   /// Discard all contexts and libraries, notify the [changes] stream that
   /// these libraries are removed.
   void discardContexts() {