[dds/dap] Include paging data for variables returned as top-level results to evaluateRequest

This reuses the existing code for child variables for building responses to `evaluate` so that we compute lengths for paging data. We have to copy them over from the variable to the EvaluateResponse because these are two unrelated types that happen to have the same fields for this data.

Fixes Dart-Code/Dart-Code#5532

Change-Id: I7ca4c522cdb27ce8dce3f7c3a78189417eb93bf1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/432941
Reviewed-by: Ben Konyi <[email protected]>
Reviewed-by: Derek Xu <[email protected]>
Commit-Queue: Derek Xu <[email protected]>
Commit-Queue: Ben Konyi <[email protected]>

Author: DanTup

pkg/dds/CHANGELOG.md

@@ -1,5 +1,6 @@
 # 5.0.3
 - [DAP] Stack frames with dots in paths will now be parsed and have locations attached to `OutputEvents`s.
+- [DAP] Responses to `evaluateRequest` that are lists now include `indexedVariables` to allow for client-side paging.
 
 # 5.0.2
 - [DAP] Handle possible race condition when interacting with web applications

pkg/dds/lib/src/dap/adapters/dart.dart

@@ -1148,26 +1148,34 @@ abstract class DartDebugAdapter<TL extends LaunchRequestArguments,
     } else if (result is vm.Sentinel) {
       throw DebugAdapterException(result.valueAsString ?? '<collected>');
     } else if (result is vm.InstanceRef && thread != null) {
-      final resultString = await _converter.convertVmInstanceRefToDisplayString(
+      final variable = await _converter.convertVmResponseToVariable(
         thread,
         result,
+        name: null,
+        evaluateName: expression,
         allowCallingToString:
             evaluateToStringInDebugViews || shouldExpandTruncatedValues,
-        format: format,
         allowTruncatedValue: !shouldExpandTruncatedValues,
+        format: format,
       );
 
-      final variablesReference = _converter.isSimpleKind(result.kind)
-          ? 0
-          : thread.storeData(VariableData(result, format));
-
       // Store the expression that gets this object as we may need it to
       // compute evaluateNames for child objects later.
       storeEvaluateName(result, expression);
 
       sendResponse(EvaluateResponseBody(
-        result: resultString,
-        variablesReference: variablesReference,
+        // EvaluateResponse is mostly the same as a Variable response but
+        // do not share a class, so copy all fields off manually (this allows
+        // us to have a single implementation of building these fields for
+        // an instance instead of duplicating logic here).
+        result: variable.value,
+        variablesReference: variable.variablesReference,
+        indexedVariables: variable.indexedVariables,
+        namedVariables: variable.namedVariables,
+        memoryReference: variable.memoryReference,
+        presentationHint: variable.presentationHint,
+        type: variable.type,
+        valueLocationReference: variable.valueLocationReference,
       ));
     } else {
       throw DebugAdapterException(

pkg/dds/lib/src/dap/protocol_converter.dart

@@ -446,6 +446,7 @@ class ProtocolConverter {
     ThreadInfo thread,
     vm.Response response, {
     required bool allowCallingToString,
+    bool allowTruncatedValue = true,
     VariableFormat? format,
   }) async {
     if (response is vm.InstanceRef) {
@@ -454,6 +455,7 @@ class ProtocolConverter {
         response,
         allowCallingToString: allowCallingToString,
         format: format,
+        allowTruncatedValue: allowTruncatedValue,
       );
     } else if (response is vm.ErrorRef) {
       final errorMessage = response.message;
@@ -505,6 +507,7 @@ class ProtocolConverter {
     required String? name,
     required String? evaluateName,
     required bool allowCallingToString,
+    bool allowTruncatedValue = true,
     VariableFormat? format,
   }) async {
     if (response is vm.InstanceRef) {
@@ -521,6 +524,7 @@ class ProtocolConverter {
           thread,
           response,
           allowCallingToString: allowCallingToString,
+          allowTruncatedValue: allowTruncatedValue,
           format: format,
         ),
         indexedVariables:

pkg/dds/test/dap/integration/debug_eval_test.dart

@@ -694,6 +694,43 @@ void foo() {
         );
       });
     });
+
+    group('provides paging data for', () {
+      // Additional paging tests are in debug_variables_test.dart
+      test('Lists', () async {
+        final client = dap.client;
+        final testFile = dap.createTestFile('''
+void main(List<String> args) {
+  var myList = List.generate(10000, (i) => i);
+  print('Hello!'); $breakpointMarker
+}''');
+        final breakpointLine = lineWith(testFile, breakpointMarker);
+
+        final stop = await client.hitBreakpoint(testFile, breakpointLine);
+        final topFrameId = await client.getTopFrameId(stop.threadId!);
+        final evalResult = await client.expectEvalResult(
+            topFrameId, 'myList', 'List (10000 items)');
+        expect(evalResult.indexedVariables, 10000);
+      });
+
+      test('Uint8List', () async {
+        final client = dap.client;
+        final testFile = dap.createTestFile('''
+import 'dart:typed_data';
+
+void main(List<String> args) {
+  var myList = Uint8List(10000);
+  print('Hello!'); $breakpointMarker
+}''');
+        final breakpointLine = lineWith(testFile, breakpointMarker);
+
+        final stop = await client.hitBreakpoint(testFile, breakpointLine);
+        final topFrameId = await client.getTopFrameId(stop.threadId!);
+        final evalResult = await client.expectEvalResult(
+            topFrameId, 'myList', 'Uint8List (10000 items)');
+        expect(evalResult.indexedVariables, 10000);
+      });
+    });
     // These tests can be slow due to starting up the external server process.
   }, timeout: Timeout.none);
 }