Fix for PartDirective annotations while applying resynthesized element model.

pkg/analyzer/test/generated/declaration_resolver_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
 library engine.declaration_resolver_test;
 
 import 'dart:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 201 matching lines @@
     unitElement.setAnnotations(unit.directives[1].offset, []);
     expect(unitElement.library.imports[0].metadata, hasLength(1));
     expect(unitElement.library.imports[1].metadata, hasLength(1));
     // DeclarationResolver on the clone should succeed.
     CompilationUnit clonedUnit = AstCloner.clone(unit);
     new DeclarationResolver().resolve(clonedUnit, unit.element);
     expect(unit.directives[0].metadata.single.name.name, 'a');
     expect(unit.directives[1].metadata.single.name.name, 'b');
   }
 
+  solo_test_metadata_partDirective_resynthesized() async {

[Brian Wilkerson, 2017/01/31 19:40:07]

Remove "solo_".

+    addNamedSource('/part_a.dart', 'part of L;');
+    addNamedSource('/part_b.dart', 'part of L;');
+
+    CompilationUnit unit = await resolveSource(r'''
+library L;
+
+@a
+part "part_a.dart";
+
+@b
+part "part_b.dart";
+
+const a = null;
+const b = null;
+''');
+    expect(unit.directives[1].metadata.single.name.name, 'a');
+    expect(unit.directives[2].metadata.single.name.name, 'b');
+    var unitElement = unit.element as CompilationUnitElementImpl;
+    // Damage the unit element - as if "setAnnotations" were not called.
+    // The ImportElement(s) still have the metadata, we should use it.
+    unitElement.setAnnotations(unit.directives[1].offset, []);
+    unitElement.setAnnotations(unit.directives[2].offset, []);
+    expect(unitElement.library.parts[0].metadata, hasLength(1));
+    expect(unitElement.library.parts[1].metadata, hasLength(1));
+    // DeclarationResolver on the clone should succeed.
+    CompilationUnit clonedUnit = AstCloner.clone(unit);
+    new DeclarationResolver().resolve(clonedUnit, unit.element);
+    expect(unit.directives[1].metadata.single.name.name, 'a');
+    expect(unit.directives[2].metadata.single.name.name, 'b');
+  }
+
   test_metadata_libraryDirective() async {
     await setupCode('@a library L;');
     checkMetadata('L');
   }
 
   test_metadata_libraryDirective_resynthesized() async {
     CompilationUnit unit =
         await resolveSource('@a library L; const a = null;');
     expect(unit.directives.single.metadata.single.name.name, 'a');
     var unitElement = unit.element as CompilationUnitElementImpl;
@@ skipping 447 matching lines @@
     expect(element.type.toString(), "<T>(T, T) → T");
     expect(t.element, same(tElement));
 
     // re-resolve
     CompilationUnit unit2 = _cloneResolveUnit(unit);
     node = _findSimpleIdentifier(unit2, code, 'max').parent;
     t = node.typeParameters.typeParameters[0];
     expect(t.element, same(tElement));
   }
 }