Resolve type parameters to bounds when checking for implementing Iterable / Map.

R=brianwilkerson@google.com

Change-Id: Ifdb8fe73cbe731bfe5e3ea130f846fabfc1ce07f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138565
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analyzer/lib/src/error/literal_element_verifier.dart

@@ -142,6 +142,8 @@ class LiteralElementVerifier {
       return;
     }
 
+    expressionType = typeSystem.resolveToBound(expressionType);
+
     InterfaceType iterableType;
     if (expressionType is InterfaceTypeImpl) {
       iterableType = expressionType.asInstanceOf(typeProvider.iterableElement);
@@ -183,6 +185,8 @@ class LiteralElementVerifier {
       return;
     }
 
+    expressionType = typeSystem.resolveToBound(expressionType);
+
     InterfaceType mapType;
     if (expressionType is InterfaceTypeImpl) {
       mapType = expressionType.asInstanceOf(typeProvider.mapElement);

pkg/analyzer/test/src/diagnostics/not_iterable_spread_test.dart

@@ -2,7 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/src/error/codes.dart';
+import 'package:analyzer/src/generated/engine.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../dart/resolution/driver_resolution.dart';
@@ -10,9 +12,30 @@ import '../dart/resolution/driver_resolution.dart';
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(NotIterableSpreadTest);
+    defineReflectiveTests(NotIterableSpreadNullSafetyTest);
   });
 }
 
+@reflectiveTest
+class NotIterableSpreadNullSafetyTest extends NotIterableSpreadTest {
+  @override
+  AnalysisOptionsImpl get analysisOptions => AnalysisOptionsImpl()
+    ..contextFeatures = FeatureSet.forTesting(
+        sdkVersion: '2.7.0', additionalFeatures: [Feature.non_nullable]);
+
+  @override
+  bool get typeToStringWithNullability => true;
+
+  test_iterable_typeParameter_bound_listQuestion() async {
+    await assertNoErrorsInCode('''
+void f<T extends List<int>?>(T a) {
+  var v = [...?a];
+  v;
+}
+''');
+  }
+}
+
 @reflectiveTest
 class NotIterableSpreadTest extends DriverResolutionTest {
   test_iterable_list() async {
@@ -28,6 +51,15 @@ var v = [...?null];
 ''');
   }
 
+  test_iterable_typeParameter_bound_list() async {
+    await assertNoErrorsInCode('''
+void f<T extends List<int>>(T a) {
+  var v = [...a];
+  v;
+}
+''');
+  }
+
   test_notIterable_direct() async {
     await assertErrorsInCode('''
 var a = 0;
@@ -64,4 +96,15 @@ var v = [if (1 > 0) ...a];
       error(CompileTimeErrorCode.NOT_ITERABLE_SPREAD, 34, 1),
     ]);
   }
+
+  test_notIterable_typeParameter_bound() async {
+    await assertErrorsInCode('''
+void f<T extends num>(T a) {
+  var v = [...a];
+  v;
+}
+''', [
+      error(CompileTimeErrorCode.NOT_ITERABLE_SPREAD, 43, 1),
+    ]);
+  }
 }

pkg/analyzer/test/src/diagnostics/not_map_spread_test.dart

@@ -2,7 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/src/error/codes.dart';
+import 'package:analyzer/src/generated/engine.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../dart/resolution/driver_resolution.dart';
@@ -10,9 +12,30 @@ import '../dart/resolution/driver_resolution.dart';
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(NotMapSpreadTest);
+    defineReflectiveTests(NotMapSpreadNullSafetyTest);
   });
 }
 
+@reflectiveTest
+class NotMapSpreadNullSafetyTest extends NotMapSpreadTest {
+  @override
+  AnalysisOptionsImpl get analysisOptions => AnalysisOptionsImpl()
+    ..contextFeatures = FeatureSet.forTesting(
+        sdkVersion: '2.7.0', additionalFeatures: [Feature.non_nullable]);
+
+  @override
+  bool get typeToStringWithNullability => true;
+
+  test_map_typeParameter_bound_mapQuestion() async {
+    await assertNoErrorsInCode('''
+void f<T extends Map<int, String>?>(T a) {
+  var v = <int, String>{...?a};
+  v;
+}
+''');
+  }
+}
+
 @reflectiveTest
 class NotMapSpreadTest extends DriverResolutionTest {
   test_map() async {
@@ -28,6 +51,15 @@ var v = <int, int>{...?null};
 ''');
   }
 
+  test_map_typeParameter_bound_map() async {
+    await assertNoErrorsInCode('''
+void f<T extends Map<int, String>>(T a) {
+  var v = <int, String>{...a};
+  v;
+}
+''');
+  }
+
   test_notMap_direct() async {
     await assertErrorsInCode('''
 var a = 0;
@@ -64,4 +96,15 @@ var v = <int, int>{if (1 > 0) ...a};
       error(CompileTimeErrorCode.NOT_MAP_SPREAD, 44, 1),
     ]);
   }
+
+  test_notMap_typeParameter_bound() async {
+    await assertErrorsInCode('''
+void f<T extends num>(T a) {
+  var v = <int, int>{...a};
+  v;
+}
+''', [
+      error(CompileTimeErrorCode.NOT_MAP_SPREAD, 53, 1),
+    ]);
+  }
 }