Resolve default values of nested parameters of function typed formal parameters.

FAILURE: /((=#is!?}=
[NoSuchMethodError: The getter 'nullabilitySuffix' was called on null.
Receiver: null
Tried calling: nullabilitySuffix, #0      Object.noSuchMethod (dart:core-patch/object_patch.dart:54:5)
flutter#1      SubtypeHelper.isSubtypeOf (package:analyzer/src/dart/element/subtype.dart:50:29)
flutter#2      TypeSystemImpl.isSubtypeOf2 (package:analyzer/src/dart/element/type_system.dart:1131:27)
flutter#3      DartObjectImpl.hasType (package:analyzer/src/dart/constant/value.dart:487:41)
flutter#4      DartObjectComputer.typeTest (package:analyzer/src/dart/constant/evaluation.dart:2159:44)
#5      ConstantVisitor.visitIsExpression (package:analyzer/src/dart/constant/evaluation.dart:1230:34)
flutter#6      IsExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:6463:49)
flutter#7      ConstantVisitor.visitConditionalExpression (package:analyzer/src/dart/constant/evaluation.dart:1104:48)
flutter#8      ConditionalExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:2265:15)
flutter#9      ConstantEvaluationEngine.computeConstantValue (package:analyzer/src/dart/constant/evaluation.dart:159:16)
flutter#10     _ConstantWalker.evaluate (package:analyzer/src/dart/constant/compute.dart:57:32)
flutter#11     DependencyWalker.walk.strongConnect (package:analyzer/src/summary/link.dart:100:13)
flutter#12     DependencyWalker.walk (package:analyzer/src/summary/link.dart:119:18)
flutter#13     computeConstants (package:analyzer/src/dart/constant/compute.dart:26:14)
flutter#14     LibraryAnalyzer._computeConstants (package:analyzer/src/dart/analysis/library_analyzer.dart:259:5)
flutter#15     LibraryAnalyzer.analyzeSync (package:analyzer/src/dart/analysis/library_analyzer.dart:145:5)
flutter#16     LibraryAnalyzer.analyze (package:analyzer/src/dart/analysis/library_analyzer.dart:107:12)
flutter#17     AnalysisDriver._computeResolvedLibrary2.<anonymous closure> (package:analyzer/src/dart/analysis/driver.dart:1414:65)
flutter#18     PerformanceLog.run (package:analyzer/src/dart/analysis/performance_logger.dart:32:15)
flutter#19     AnalysisDriver._computeResolvedLibrary2 (package:analyzer/src/dart/analysis/driver.dart:1400:20)
flutter#20     AnalysisDriver._computeResolvedLibrary.<anonymous closure> (package:analyzer/src/dart/analysis/driver.dart:1393:15)
#21     _rootRun (dart:async/zone.dart:1186:13)
#22     _CustomZone.run (dart:async/zone.dart:1090:19)
#23     _runZoned (dart:async/zone.dart:1626:10)
#24     runZoned (dart:async/zone.dart:1546:10)
#25     NullSafetyUnderstandingFlag.enableNullSafetyTypes (package:analyzer/dart/element/null_safety_understanding_flag.dart:42:12)
#26     AnalysisDriver._computeResolvedLibrary (package:analyzer/src/dart/analysis/driver.dart:1392:40)
#27     AnalysisDriver.performWork (package:analyzer/src/dart/analysis/driver.dart:962:22)
#28     AnalysisDriverScheduler._run (package:analyzer/src/dart/analysis/driver.dart:2013:24)


Change-Id: I1d5482390a7d76cccbfbdf1dd871f9473ce2826a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/175944
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/summary2/default_value_resolver.dart

@@ -98,6 +98,11 @@ class DefaultValueResolver {
   }
 
   void _parameter(ParameterElementImpl parameter) {
+    // If a function typed parameter, process nested parameters.
+    for (var localParameter in parameter.parameters) {
+      _parameter(localParameter);
+    }
+
     var node = _defaultParameter(parameter);
     if (node == null) return;
 

pkg/analyzer/test/src/summary/element_text.dart

@@ -301,16 +301,17 @@ class _ElementWriter {
     var initializers = (e as ConstructorElementImpl).constantInitializers;
     if (withFullyResolvedAst) {
       buffer.writeln(';');
-      if (initializers != null && initializers.isNotEmpty) {
-        _withIndent(() {
+      _withIndent(() {
+        if (initializers != null && initializers.isNotEmpty) {
           _writelnWithIndent('constantInitializers');
           _withIndent(() {
             for (var initializer in initializers) {
               _writeResolvedNode(initializer);
             }
           });
-        });
-      }
+        }
+        _writeParameterElementDefaultValues(e.parameters);
+      });
     } else {
       if (initializers != null) {
         writeList(' : ', '', initializers, ', ', writeNode);
@@ -407,6 +408,12 @@ class _ElementWriter {
     writeBodyModifiers(e);
 
     buffer.writeln(' {}');
+
+    if (withFullyResolvedAst) {
+      _withIndent(() {
+        _writeParameterElementDefaultValues(e.parameters);
+      });
+    }
   }
 
   void writeIf(bool flag, String str) {
@@ -530,6 +537,7 @@ class _ElementWriter {
       _withIndent(() {
         _writeResolvedTypeParameters(e.typeParameters);
         _writeResolvedMetadata(e.metadata);
+        _writeParameterElementDefaultValues(e.parameters);
       });
     }
   }
@@ -828,15 +836,17 @@ class _ElementWriter {
     writeName(e);
     writeCodeRange(e);
 
-    if (e.parameters.isNotEmpty) {
-      buffer.write('/*');
-      writeList('(', ')', e.parameters, ', ', writeParameterElement);
-      buffer.write('*/');
-    }
+    if (!withFullyResolvedAst) {
+      if (e.parameters.isNotEmpty) {
+        buffer.write('/*');
+        writeList('(', ')', e.parameters, ', ', writeParameterElement);
+        buffer.write('*/');
+      }
 
-    if (defaultValue != null) {
-      buffer.write(defaultValueSeparator);
-      writeNode(defaultValue);
+      if (defaultValue != null) {
+        buffer.write(defaultValueSeparator);
+        writeNode(defaultValue);
+      }
     }
 
     buffer.write(closeString);
@@ -1194,6 +1204,30 @@ class _ElementWriter {
     buffer.writeln(line);
   }
 
+  void _writeParameterElementDefaultValues(
+    List<ParameterElement> parameters, {
+    String enclosingNames = '',
+  }) {
+    for (var parameter in parameters) {
+      if (parameter is DefaultParameterElementImpl) {
+        var defaultValue = parameter.constantInitializer;
+        if (defaultValue != null) {
+          _writelnWithIndent(enclosingNames + parameter.name);
+          _withIndent(() {
+            _writeResolvedNode(defaultValue);
+          });
+        }
+      }
+      var subParameters = parameter.parameters;
+      _withIndent(() {
+        _writeParameterElementDefaultValues(
+          subParameters,
+          enclosingNames: enclosingNames + parameter.name + '::',
+        );
+      });
+    }
+  }
+
   void _writeResolvedMetadata(List<ElementAnnotation> metadata) {
     if (metadata.isNotEmpty) {
       _writelnWithIndent('metadata');

pkg/analyzer/test/src/summary/resynthesize_common.dart

@@ -4832,7 +4832,7 @@ class A {
         r'''
 class A {
   final int _f;
-  const A([int f = 0]);
+  const A([int f]);
     constantInitializers
       ConstructorFieldInitializer
         equals: =
@@ -4844,6 +4844,10 @@ class A {
           staticElement: self::@class::A::@field::_f
           staticType: null
           token: _f
+    f
+      IntegerLiteral
+        literal: 0
+        staticType: int
 }
 ''',
         withFullyResolvedAst: true);
@@ -5600,6 +5604,30 @@ class B {
 ''');
   }
 
+  test_defaultValue_inFunctionTypedFormalParameter() async {
+    var library = await checkLibrary('''
+void f( g({a: 0 is int}) ) {}
+''');
+    checkElementText(
+        library,
+        r'''
+void f(dynamic Function({dynamic a}) g) {}
+    g::a
+      IsExpression
+        expression: IntegerLiteral
+          literal: 0
+          staticType: int
+        staticType: bool
+        type: TypeName
+          name: SimpleIdentifier
+            staticElement: dart:core::@class::int
+            staticType: null
+            token: int
+          type: int
+''',
+        withFullyResolvedAst: true);
+  }
+
   test_defaultValue_refersToExtension_method_inside() async {
     var library = await checkLibrary('''
 class A {}