[analysis_server] Support dart.updateImportsOnRename setting for updating directives on renames

This setting is already supported in VS Code but accidentally stopped working in the switch to LSP. This change prevents/removes the registration for willRenameFiles so that a client won't call the server when files are renamed if this setting is `false`.

Change-Id: Ia7b22b9fc2f119d0e7f98f4e2c5f0bac994a28af
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/247544
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

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

@@ -213,5 +213,17 @@ class LspResourceClientConfiguration {
   /// Values are "always", "prompt", "never". Any other values should be treated
   /// like "never".
   String get renameFilesWithClasses =>
-      _settings['renameFilesWithClasses'] as String? ?? 'never';
+      _settings['renameFilesWithClasses'] as String? ??
+      _fallback?.renameFilesWithClasses ??
+      'never';
+
+  /// Whether to update imports and other directives when files are renamed.
+  ///
+  /// This setting works by controlling whether the server registers for
+  /// `willRenameFiles` requests from the client. Changing the value after
+  /// initialization will register/unregister appropriately.
+  bool get updateImportsOnRename =>
+      _settings['updateImportsOnRename'] as bool? ??
+      _fallback?.updateImportsOnRename ??
+      true;
 }

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

@@ -341,6 +341,8 @@ class ServerCapabilitiesComputer {
         _server.clientConfiguration.global.enableSdkFormatter;
     final previewCommitCharacters =
         _server.clientConfiguration.global.previewCommitCharacters;
+    final updateImportsOnRename =
+        _server.clientConfiguration.global.updateImportsOnRename;
 
     /// Helper for creating registrations with IDs.
     void register(bool condition, Method method, [ToJsonable? options]) {
@@ -486,7 +488,7 @@ class ServerCapabilitiesComputer {
       TextDocumentRegistrationOptions(documentSelector: fullySupportedTypes),
     );
     register(
-      dynamicRegistrations.fileOperations,
+      updateImportsOnRename && dynamicRegistrations.fileOperations,
       Method.workspace_willRenameFiles,
       fileOperationRegistrationOptions,
     );

pkg/analysis_server/test/lsp/will_rename_files_test.dart

@@ -18,6 +18,74 @@ void main() {
 
 @reflectiveTest
 class WillRenameFilesTest extends AbstractLspAnalysisServerTest {
+  bool isWillRenameFilesRegistration(Registration registration) =>
+      registration.method == Method.workspace_willRenameFiles.toJson();
+
+  Future<void> test_registration_defaultsEnabled() async {
+    final registrations = <Registration>[];
+    await monitorDynamicRegistrations(
+      registrations,
+      () => initialize(
+        workspaceCapabilities: withAllSupportedWorkspaceDynamicRegistrations(
+            emptyWorkspaceClientCapabilities),
+      ),
+    );
+
+    expect(
+      registrations.where(isWillRenameFilesRegistration),
+      hasLength(1),
+    );
+  }
+
+  Future<void> test_registration_disabled() async {
+    final registrations = <Registration>[];
+    await provideConfig(
+      () => monitorDynamicRegistrations(
+        registrations,
+        () => initialize(
+          textDocumentCapabilities:
+              withAllSupportedTextDocumentDynamicRegistrations(
+                  emptyTextDocumentClientCapabilities),
+          workspaceCapabilities: withAllSupportedWorkspaceDynamicRegistrations(
+              withConfigurationSupport(emptyWorkspaceClientCapabilities)),
+        ),
+      ),
+      {'updateImportsOnRename': false},
+    );
+
+    expect(
+      registrations.where(isWillRenameFilesRegistration),
+      isEmpty,
+    );
+  }
+
+  Future<void> test_registration_disabledThenEnabled() async {
+    // Start disabled.
+    await provideConfig(
+      () => initialize(
+        textDocumentCapabilities:
+            withAllSupportedTextDocumentDynamicRegistrations(
+                emptyTextDocumentClientCapabilities),
+        workspaceCapabilities: withAllSupportedWorkspaceDynamicRegistrations(
+            withConfigurationSupport(emptyWorkspaceClientCapabilities)),
+      ),
+      {'updateImportsOnRename': false},
+    );
+
+    // Collect any new registrations when enabled.
+    final registrations = <Registration>[];
+    await monitorDynamicRegistrations(
+      registrations,
+      () => updateConfig({'updateImportsOnRename': true}),
+    );
+
+    // Expect that willRenameFiles was included.
+    expect(
+      registrations.where(isWillRenameFilesRegistration),
+      hasLength(1),
+    );
+  }
+
   Future<void> test_rename_updatesImports() async {
     final otherFilePath = join(projectFolderPath, 'lib', 'other.dart');
     final otherFileUri = Uri.file(otherFilePath);

pkg/analysis_server/tool/lsp_spec/README.md

@@ -40,6 +40,7 @@ Client workspace settings are requested with `workspace/configuration` during in
 - `dart.showTodos` (`bool?`): Whether to generate diagnostics for TODO comments. If unspecified, diagnostics will not be generated.
 - `dart.renameFilesWithClasses` (`String`): When set to `"always"`, will include edits to rename files when classes are renamed if the filename matches the class name (but in snake_form). When set to `"prompt"`, a prompt will be shown on each class rename asking to confirm the file rename. Otherwise, files will not be renamed. Renames are performed using LSP's ResourceOperation edits - that means the rename is simply included in the resulting `WorkspaceEdit` and must be handled by the client.
 - `dart.enableSnippets` (`bool?`): Whether to include code snippets (such as `class`, `stful`, `switch`) in code completion. When unspecified, snippets will be included.
+- `dart.updateImportsOnRename` (`bool?`): Whether to update imports and other directives when files are renamed. When unspecified, imports will be updated if the client supports `willRenameFiles` requests.
 
 ## Method Status