Refactorings run with multiple AnalysisContext(s) and sessions.

If we use just the session that produced the resolved unit, we will
not update other packages for example.

I tried to apply a refactoring to `LanguageVersionImpl` from `_fe_analyzer_shared`, and it did not update `analyzer`. With this change it does update :-)

Change-Id: I47fc28b4adba59c8e025e1bfe17490e4038d28ba
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/310973
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

Author: scheglov

pkg/analysis_server/lib/src/lsp/handlers/code_actions/dart.dart

@@ -204,6 +204,7 @@ class DartCodeActionsProducer extends AbstractCodeActionsProducer {
       // New interactive refactors.
       final context = RefactoringContext(
         server: server,
+        startSessions: await server.currentSessions,
         resolvedLibraryResult: library,
         resolvedUnitResult: unit,
         selectionOffset: offset,

pkg/analysis_server/lib/src/lsp/handlers/commands/refactor_command_handler.dart

@@ -62,6 +62,7 @@ class RefactorCommandHandler extends SimpleEditCommandHandler {
       }
       var context = RefactoringContext(
         server: server,
+        startSessions: await server.currentSessions,
         resolvedLibraryResult: library,
         resolvedUnitResult: unit,
         selectionOffset: offset,

pkg/analysis_server/lib/src/services/refactoring/framework/refactoring_context.dart

@@ -20,6 +20,9 @@ class AbstractRefactoringContext {
   /// Return the search engine used to search outside the resolved library.
   final SearchEngine searchEngine;
 
+  /// The sessions at the start of the refactoring.
+  final List<AnalysisSession> startSessions;
+
   /// The result of resolving the library in which a refactoring was requested.
   final ResolvedLibraryResult resolvedLibraryResult;
 
@@ -49,11 +52,12 @@ class AbstractRefactoringContext {
       AnalysisSessionHelper(session);
 
   /// The change workspace associated with this refactoring.
-  late final ChangeWorkspace workspace = DartChangeWorkspace([session]);
+  late final ChangeWorkspace workspace = DartChangeWorkspace(startSessions);
 
   /// Initialize a newly created refactoring context.
   AbstractRefactoringContext({
     required this.searchEngine,
+    required this.startSessions,
     required this.resolvedLibraryResult,
     required this.resolvedUnitResult,
     required this.selectionOffset,
@@ -89,6 +93,7 @@ class RefactoringContext extends AbstractRefactoringContext {
   /// Initialize a newly created refactoring context.
   RefactoringContext({
     required this.server,
+    required super.startSessions,
     required super.resolvedLibraryResult,
     required super.resolvedUnitResult,
     required super.selectionOffset,

pkg/analysis_server/test/services/refactoring/agnostic/change_method_signature_test.dart

@@ -104,6 +104,7 @@ class AbstractChangeMethodSignatureTest extends AbstractContextTest {
 
     refactoringContext = AbstractRefactoringContext(
       searchEngine: SearchEngineImpl(allDrivers),
+      startSessions: [resolvedLibraryResult.session],
       resolvedLibraryResult: resolvedLibraryResult,
       resolvedUnitResult: unitResult,
       selectionOffset: selectionRange.offset,