Elements. Migrate PrefixElementResolutionTest into LibraryFragmentElementTest.

Change-Id: Id894f7a51504de5dd9dd8bce62f0fddca4734267
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/406440
Reviewed-by: Phil Quitslund <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/test/src/dart/resolution/assignment_test.dart

@@ -1559,7 +1559,9 @@ AssignmentExpression
   readElement2: <null>
   readType: null
   writeElement: <null>
-  writeElement2: <null>
+  writeElement2: multiplyDefinedElement
+    package:test/a.dart::@class::C
+    package:test/b.dart::@class::C
   writeType: InvalidType
   staticElement: <null>
   element: <null>

pkg/analyzer/test/src/dart/resolution/method_invocation_test.dart

@@ -1765,7 +1765,9 @@ MethodInvocation
   methodName: SimpleIdentifier
     token: foo
     staticElement: <null>
-    element: <null>
+    element: multiplyDefinedElement
+      package:test/a.dart::@function::foo
+      package:test/b.dart::@function::foo
     staticType: void Function(int)
   argumentList: ArgumentList
     leftParenthesis: (
@@ -1811,7 +1813,9 @@ MethodInvocation
   methodName: SimpleIdentifier
     token: foo
     staticElement: <null>
-    element: <null>
+    element: multiplyDefinedElement
+      package:test/a.dart::@function::foo
+      package:test/b.dart::@function::foo
     staticType: void Function(int)
   argumentList: ArgumentList
     leftParenthesis: (

pkg/analyzer/test/src/dart/resolution/named_type_test.dart

@@ -788,7 +788,9 @@ void f(A a) {}
 NamedType
   name: A
   element: <null>
-  element2: <null>
+  element2: multiplyDefinedElement
+    package:test/a.dart::@class::A
+    package:test/b.dart::@class::A
   type: InvalidType
 ''');
   }

pkg/analyzer/test/src/dart/resolution/prefix_element_test.dart

@@ -447,10 +447,6 @@ mixin ResolutionTest implements ResourceProviderMixin {
   ExpectedContextMessage message(File file, int offset, int length) =>
       ExpectedContextMessage(file, offset, length);
 
-  Matcher multiplyDefinedElementMatcher(List<Element> elements) {
-    return _MultiplyDefinedElementMatcher(elements);
-  }
-
   Future<ResolvedUnitResult> resolveFile(File file);
 
   /// Resolve [file] into [result].
@@ -507,27 +503,6 @@ mixin ResolutionTest implements ResourceProviderMixin {
   }
 }
 
-class _MultiplyDefinedElementMatcher extends Matcher {
-  final Iterable<Element> elements;
-
-  _MultiplyDefinedElementMatcher(this.elements);
-
-  @override
-  Description describe(Description description) {
-    return description.add('elements: $elements\n');
-  }
-
-  @override
-  bool matches(element, Map matchState) {
-    if (element is MultiplyDefinedElementImpl) {
-      var actualSet = element.conflictingElements.toSet();
-      actualSet.removeAll(elements);
-      return actualSet.isEmpty;
-    }
-    return false;
-  }
-}
-
 extension ResolvedUnitResultExtension on ResolvedUnitResult {
   FindElement get findElement {
     return FindElement(unit);

pkg/analyzer/test/src/dart/resolution/resolution.dart

@@ -89,7 +89,6 @@ import 'pattern_assignment_test.dart' as pattern_assignment;
 import 'pattern_variable_declaration_statement_test.dart'
     as pattern_variable_declaration_statement;
 import 'postfix_expression_test.dart' as postfix_expression;
-import 'prefix_element_test.dart' as prefix_element;
 import 'prefix_expression_test.dart' as prefix_expression;
 import 'prefixed_identifier_test.dart' as prefixed_identifier;
 import 'property_access_test.dart' as property_access;
@@ -197,7 +196,6 @@ main() {
     pattern_assignment.main();
     pattern_variable_declaration_statement.main();
     postfix_expression.main();
-    prefix_element.main();
     prefix_expression.main();
     prefixed_identifier.main();
     property_access.main();