diff --git a/lib/src/model.dart b/lib/src/model.dart
index d5b6d623c7..b7bb0da02c 100644
--- a/lib/src/model.dart
+++ b/lib/src/model.dart
@@ -38,8 +38,6 @@ import 'package:analyzer/src/dart/element/member.dart'
 import 'package:analyzer/src/dart/sdk/sdk.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
-import 'package:analyzer/src/generated/resolver.dart'
-    show Namespace, NamespaceBuilder;
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
@@ -153,11 +151,14 @@ mixin Extendable on ContainerMember {
 mixin ContainerMember on ModelElement implements EnclosedElement {
   /// True if this [ContainerMember] is inherited from a different class.
   bool get isInherited;
+
   /// True if this [ContainerMember] is overriding a superclass.
   bool get isOverride;
+
   /// True if this [ContainerMember] has a parameter whose type is overridden
   /// by a subtype.
   bool get isCovariant;
+
   /// True if this [ContainerMember] is from an applicable [Extension].
   /// False otherwise, including if this [ContainerMember]'s [enclosingElement]
   /// is the extension it was declared in.
@@ -391,8 +392,8 @@ class ContainerAccessor extends Accessor with ContainerMember, Inheritable {
       PackageGraph packageGraph)
       : super(element, library, packageGraph, null);
 
-  ContainerAccessor.inherited(PropertyAccessorElement element,
-      Library library, PackageGraph packageGraph, this._enclosingElement,
+  ContainerAccessor.inherited(PropertyAccessorElement element, Library library,
+      PackageGraph packageGraph, this._enclosingElement,
       {Member originalMember})
       : super(element, library, packageGraph, originalMember) {
     _isInherited = true;
@@ -539,7 +540,6 @@ class Accessor extends ModelElement implements EnclosedElement {
   @override
   bool get isCanonical => enclosingCombo.isCanonical;
 
-
   @override
   String get href {
     return enclosingCombo.href;
@@ -999,8 +999,8 @@ class Class extends Container
       }).toSet();
 
       for (ExecutableElement e in inheritedMethodElements) {
-        Method m =
-            ModelElement.from(e, library, packageGraph, enclosingContainer: this);
+        Method m = ModelElement.from(e, library, packageGraph,
+            enclosingContainer: this);
         _inheritedMethods.add(m);
       }
       _inheritedMethods.sort(byName);
@@ -1025,8 +1025,8 @@ class Class extends Container
             !operatorNames.contains(e.name));
       }).toSet();
       for (ExecutableElement e in inheritedOperatorElements) {
-        Operator o =
-            ModelElement.from(e, library, packageGraph, enclosingContainer: this);
+        Operator o = ModelElement.from(e, library, packageGraph,
+            enclosingContainer: this);
         _inheritedOperators.add(o);
       }
       _inheritedOperators.sort(byName);
@@ -1357,7 +1357,8 @@ class Extension extends Container
       if (f.setter != null) {
         setter = ContainerAccessor(f.setter, library, packageGraph);
       }
-      return ModelElement.from(f, library, packageGraph, getter: getter, setter: setter) as Field;
+      return ModelElement.from(f, library, packageGraph,
+          getter: getter, setter: setter) as Field;
     }).toList(growable: false)
       ..sort(byName);
 
@@ -2347,7 +2348,7 @@ class _HashableChildLibraryElementVisitor
 
 class Library extends ModelElement with Categorization, TopLevelContainer {
   List<TopLevelVariable> _variables;
-  Namespace _exportedNamespace;
+  List<Element> _exportedAndLocalElements;
   String _name;
 
   factory Library(LibraryElement element, PackageGraph packageGraph) {
@@ -2367,11 +2368,39 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
     _HashableChildLibraryElementVisitor((Element e) =>
             packageGraph._populateModelNodeFor(e, _compilationUnitMap))
         .visitElement(element);
-    _exportedNamespace =
-        NamespaceBuilder().createExportNamespaceForLibrary(element);
+
+    // Initialize the list of elements defined in this library and
+    // exported via its export directives.
+    Set<Element> exportedAndLocalElements = _libraryElement
+        .exportNamespace
+        .definedNames
+        .values
+        .toSet();
+    // TODO(jcollins-g): Consider switch to [_libraryElement.topLevelElements].
+    exportedAndLocalElements
+        .addAll(getDefinedElements(_libraryElement.definingCompilationUnit));
+    for (CompilationUnitElement cu in _libraryElement.parts) {
+      exportedAndLocalElements.addAll(getDefinedElements(cu));
+    }
+    _exportedAndLocalElements = exportedAndLocalElements.toList();
+
     _package._allLibraries.add(this);
   }
 
+  static Iterable<Element> getDefinedElements(
+      CompilationUnitElement compilationUnit) {
+    return quiver.concat([
+      compilationUnit.accessors,
+      compilationUnit.enums,
+      compilationUnit.extensions,
+      compilationUnit.functions,
+      compilationUnit.functionTypeAliases,
+      compilationUnit.mixins,
+      compilationUnit.topLevelVariables,
+      compilationUnit.types,
+    ]);
+  }
+
   List<String> _allOriginalModelElementNames;
 
   final Package _package;
@@ -2418,14 +2447,16 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
   @override
   CharacterLocation get characterLocation {
     if (element.nameOffset == -1) {
-      assert(isAnonymous, 'Only anonymous libraries are allowed to have no declared location');
+      assert(isAnonymous,
+          'Only anonymous libraries are allowed to have no declared location');
       return CharacterLocation(1, 1);
     }
     return super.characterLocation;
   }
 
   @override
-  CompilationUnitElement get compilationUnitElement => (element as LibraryElement).definingCompilationUnit;
+  CompilationUnitElement get compilationUnitElement =>
+      (element as LibraryElement).definingCompilationUnit;
 
   @override
   Iterable<Class> get classes => allClasses.where((c) => !c.isErrorOrException);
@@ -2433,24 +2464,11 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
   @override
   Iterable<Extension> get extensions {
     if (_extensions == null) {
-      // De-dupe extensions coming from multiple exported libraries at once.
-      Set<ExtensionElement> extensionElements = Set();
-      extensionElements.addAll(_libraryElement.definingCompilationUnit.extensions);
-      for (CompilationUnitElement cu in _libraryElement.parts) {
-        extensionElements.addAll(cu.extensions);
-      }
-      for (LibraryElement le in _libraryElement.exportedLibraries) {
-        extensionElements.addAll(le.definingCompilationUnit.extensions
-            .where((t) => _exportedNamespace.definedNames.values.contains(t.name)));
-      }
-
-      extensionElements.addAll(_exportedNamespace.definedNames.values
-          .whereType<ExtensionElement>());
-
-      _extensions = extensionElements
+      _extensions = _exportedAndLocalElements
+          .whereType<ExtensionElement>()
           .map((e) => ModelElement.from(e, this, packageGraph) as Extension)
           .toList(growable: false)
-        ..sort(byName);
+            ..sort(byName);
     }
     return _extensions;
   }
@@ -2605,40 +2623,37 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
 
   @override
   List<Enum> get enums {
-    if (_enums != null) return _enums;
-    List<ClassElement> enumClasses = [];
-    enumClasses.addAll(_exportedNamespace.definedNames.values
-        .whereType<ClassElement>()
-        .where((element) => element.isEnum));
-    _enums = enumClasses
-        .map((e) => ModelElement.from(e, this, packageGraph) as Enum)
-        .toList(growable: false)
-          ..sort(byName);
-
+    if (_enums == null) {
+      _enums = _exportedAndLocalElements
+          .whereType<ClassElement>()
+          .where((element) => element.isEnum)
+          .map((e) => ModelElement.from(e, this, packageGraph) as Enum)
+          .toList(growable: false)
+            ..sort(byName);
+    }
     return _enums;
   }
 
   @override
   List<Mixin> get mixins {
-    if (_mixins != null) return _mixins;
-
-    /// Can not be [MixinElementImpl] because [ClassHandle]s are sometimes
-    /// returned from _exportedNamespace.
-    List<ClassElement> mixinClasses = [];
-    mixinClasses.addAll(_exportedNamespace.definedNames.values
-        .whereType<ClassElement>()
-        .where((ClassElement c) => c.isMixin));
-    _mixins = mixinClasses
-        .map((e) => ModelElement.from(e, this, packageGraph) as Mixin)
-        .toList(growable: false)
-          ..sort(byName);
+    if (_mixins == null) {
+      /// Can not be [MixinElementImpl] because [ClassHandle]s are sometimes
+      /// returned from _exportedElements.
+      _mixins = _exportedAndLocalElements
+          .whereType<ClassElement>()
+          .where((ClassElement c) => c.isMixin)
+          .map((e) => ModelElement.from(e, this, packageGraph) as Mixin)
+          .toList(growable: false)
+            ..sort(byName);
+    }
     return _mixins;
   }
 
   @override
   List<Class> get exceptions {
     if (_exceptions == null) {
-      _exceptions = allClasses.where((c) => c.isErrorOrException).toList(growable: false);
+      _exceptions =
+          allClasses.where((c) => c.isErrorOrException).toList(growable: false);
     }
     return _exceptions;
   }
@@ -2648,21 +2663,13 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
 
   @override
   List<ModelFunction> get functions {
-    if (_functions != null) return _functions;
-
-    Set<FunctionElement> elements = Set();
-    elements.addAll(_libraryElement.definingCompilationUnit.functions);
-    for (CompilationUnitElement cu in _libraryElement.parts) {
-      elements.addAll(cu.functions);
+    if (_functions == null) {
+      _functions =
+          _exportedAndLocalElements.whereType<FunctionElement>().map((e) {
+        return ModelElement.from(e, this, packageGraph) as ModelFunction;
+      }).toList(growable: false)
+            ..sort(byName);
     }
-    elements.addAll(
-        _exportedNamespace.definedNames.values.whereType<FunctionElement>());
-
-    _functions = elements.map((e) {
-      return ModelElement.from(e, this, packageGraph) as ModelFunction;
-    }).toList(growable: false)
-      ..sort(byName);
-
     return _functions;
   }
 
@@ -2742,49 +2749,25 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
 
   @override
   List<Typedef> get typedefs {
-    if (_typedefs != null) return _typedefs;
-
-    Set<FunctionTypeAliasElement> elements = Set();
-    elements
-        .addAll(_libraryElement.definingCompilationUnit.functionTypeAliases);
-    for (CompilationUnitElement cu in _libraryElement.parts) {
-      elements.addAll(cu.functionTypeAliases);
+    if (_typedefs == null) {
+      _typedefs = _exportedAndLocalElements
+          .whereType<FunctionTypeAliasElement>()
+          .map((e) => ModelElement.from(e, this, packageGraph) as Typedef)
+          .toList(growable: false)
+            ..sort(byName);
     }
-
-    elements.addAll(_exportedNamespace.definedNames.values
-        .whereType<FunctionTypeAliasElement>());
-    _typedefs = elements
-        .map((e) => ModelElement.from(e, this, packageGraph) as Typedef)
-        .toList(growable: false)
-          ..sort(byName);
-
     return _typedefs;
   }
 
   List<Class> get allClasses {
-    if (_classes != null) return _classes;
-
-    // De-dupe classes coming from multiple exported libraries at once.
-    Set<ClassElement> types = Set();
-    types.addAll(_libraryElement.definingCompilationUnit.types);
-    for (CompilationUnitElement cu in _libraryElement.parts) {
-      types.addAll(cu.types);
-    }
-    for (LibraryElement le in _libraryElement.exportedLibraries) {
-      types.addAll(le.definingCompilationUnit.types
-          .where((t) => _exportedNamespace.definedNames.values.contains(t.name)));
+    if (_classes == null) {
+      _classes = _exportedAndLocalElements
+          .whereType<ClassElement>()
+          .where((e) => !e.isMixin && !e.isEnum)
+          .map((e) => ModelElement.from(e, this, packageGraph) as Class)
+          .toList(growable: false)
+            ..sort(byName);
     }
-
-    types.addAll(_exportedNamespace.definedNames.values
-        .whereType<ClassElement>()
-        .where((e) => !e.isMixin && !e.isEnum));
-
-    _classes = types
-        .map((e) => ModelElement.from(e, this, packageGraph) as Class)
-        .toList(growable: false)
-          ..sort(byName);
-
-    assert(!_classes.any((Class c) => c is Mixin));
     return _classes;
   }
 
@@ -2795,34 +2778,29 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
   }
 
   List<TopLevelVariable> _getVariables() {
-    if (_variables != null) return _variables;
-
-    Set<TopLevelVariableElement> elements = Set();
-    elements.addAll(_libraryElement.definingCompilationUnit.topLevelVariables);
-    for (CompilationUnitElement cu in _libraryElement.parts) {
-      elements.addAll(cu.topLevelVariables);
-    }
-    _exportedNamespace.definedNames.values.forEach((element) {
-      if (element is PropertyAccessorElement) {
-        elements.add(element.variable);
-      }
-    });
-    _variables = [];
-    for (TopLevelVariableElement element in elements) {
-      Accessor getter;
-      if (element.getter != null) {
-        getter = ModelElement.from(element.getter, this, packageGraph);
-      }
-      Accessor setter;
-      if (element.setter != null) {
-        setter = ModelElement.from(element.setter, this, packageGraph);
+    if (_variables == null) {
+      Set<TopLevelVariableElement> elements = _exportedAndLocalElements
+          .whereType<TopLevelVariableElement>()
+          .toSet();
+      elements.addAll(_exportedAndLocalElements
+          .whereType<PropertyAccessorElement>()
+          .map((a) => a.variable));
+      _variables = [];
+      for (TopLevelVariableElement element in elements) {
+        Accessor getter;
+        if (element.getter != null) {
+          getter = ModelElement.from(element.getter, this, packageGraph);
+        }
+        Accessor setter;
+        if (element.setter != null) {
+          setter = ModelElement.from(element.setter, this, packageGraph);
+        }
+        ModelElement me = ModelElement.from(element, this, packageGraph,
+            getter: getter, setter: setter);
+        _variables.add(me);
       }
-      ModelElement me = ModelElement.from(element, this, packageGraph,
-          getter: getter, setter: setter);
-      _variables.add(me);
+      _variables.sort(byName);
     }
-
-    _variables.sort(byName);
     return _variables;
   }
 
@@ -2973,8 +2951,8 @@ class Method extends ModelElement
     _calcTypeParameters();
   }
 
-  Method.inherited(MethodElement element, this._enclosingContainer, Library library,
-      PackageGraph packageGraph,
+  Method.inherited(MethodElement element, this._enclosingContainer,
+      Library library, PackageGraph packageGraph,
       {Member originalMember})
       : super(element, library, packageGraph, originalMember) {
     _isInherited = true;
@@ -3835,8 +3813,10 @@ abstract class ModelElement extends Canonicalization
     if (!_characterLocationIsSet) {
       LineInfo lineInfo = compilationUnitElement.lineInfo;
       _characterLocationIsSet = true;
-      assert(element.nameOffset >= 0, 'Invalid location data for element: $fullyQualifiedName');
-      assert(lineInfo != null, 'No lineInfo data available for element: $fullyQualifiedName');
+      assert(element.nameOffset >= 0,
+          'Invalid location data for element: $fullyQualifiedName');
+      assert(lineInfo != null,
+          'No lineInfo data available for element: $fullyQualifiedName');
       if (element.nameOffset >= 0) {
         _characterLocation = lineInfo?.getLocation(element.nameOffset);
       }
@@ -3844,7 +3824,8 @@ abstract class ModelElement extends Canonicalization
     return _characterLocation;
   }
 
-  CompilationUnitElement get compilationUnitElement => element.getAncestor((e) => e is CompilationUnitElement);
+  CompilationUnitElement get compilationUnitElement =>
+      element.getAncestor((e) => e is CompilationUnitElement);
 
   bool get hasAnnotations => annotations.isNotEmpty;
 
@@ -5347,8 +5328,7 @@ class PackageGraph {
 
     List<String> messageParts = [warningMessage];
     if (warnable != null) {
-      messageParts
-          .add("$warnablePrefix $warnableName: ${warnable.location}");
+      messageParts.add("$warnablePrefix $warnableName: ${warnable.location}");
     }
     if (referredFrom != null) {
       for (Locatable referral in referredFrom) {
diff --git a/test/dartdoc_integration_test.dart b/test/dartdoc_integration_test.dart
index bc289d041a..1007c41a34 100644
--- a/test/dartdoc_integration_test.dart
+++ b/test/dartdoc_integration_test.dart
@@ -232,26 +232,21 @@ void main() {
     }, timeout: Timeout.factor(2));
 
     test('--footer-text excludes version', () async {
-      String _testPackagePath =
-          path.fromUri(_currentFileUri.resolve('../testing/test_package_options'));
+      String _testPackagePath = path
+          .fromUri(_currentFileUri.resolve('../testing/test_package_options'));
 
-      var args = <String>[
-        dartdocPath,
-        '--output',
-        tempDir.path
-      ];
+      var args = <String>[dartdocPath, '--output', tempDir.path];
 
       await subprocessLauncher.runStreamed(Platform.resolvedExecutable, args,
           workingDirectory: _testPackagePath);
 
       File outFile = File(path.join(tempDir.path, 'index.html'));
-      RegExp footerRegex = RegExp('<footer>(.*\s*?\n?)+?</footer>', multiLine: true);
+      RegExp footerRegex =
+          RegExp('<footer>(.*\s*?\n?)+?</footer>', multiLine: true);
       // get footer, check for version number
       RegExpMatch m = footerRegex.firstMatch(outFile.readAsStringSync());
       RegExp version = RegExp(r'(\d+\.)?(\d+\.)?(\*|\d+)');
       expect(version.hasMatch(m.group(0)), false);
     });
-
   }, timeout: Timeout.factor(4));
 }
-
diff --git a/test/dartdoc_test.dart b/test/dartdoc_test.dart
index 078d3e8d70..d049533348 100644
--- a/test/dartdoc_test.dart
+++ b/test/dartdoc_test.dart
@@ -258,7 +258,7 @@ void main() {
         expect(p.name, 'test_package');
         expect(p.hasDocumentationFile, isTrue);
         // Total number of public libraries in test_package.
-        expect(packageGraph.defaultPackage.publicLibraries, hasLength(15));
+        expect(packageGraph.defaultPackage.publicLibraries, hasLength(16));
         expect(packageGraph.localPackages.length, equals(1));
       });
 
@@ -327,7 +327,7 @@ void main() {
       PackageGraph p = results.packageGraph;
       expect(p.defaultPackage.name, 'test_package');
       expect(p.defaultPackage.hasDocumentationFile, isTrue);
-      expect(p.localPublicLibraries, hasLength(14));
+      expect(p.localPublicLibraries, hasLength(15));
       expect(p.localPublicLibraries.map((lib) => lib.name).contains('fake'),
           isFalse);
     });
diff --git a/test/model_test.dart b/test/model_test.dart
index c2a076e218..42317ce34b 100644
--- a/test/model_test.dart
+++ b/test/model_test.dart
@@ -494,7 +494,7 @@ void main() {
       expect(
           packageGraph
               .localPackages.first.defaultCategory.publicLibraries.length,
-          equals(8));
+          equals(9));
     });
 
     test('Verify libraries with multiple categories show up in multiple places',
@@ -518,7 +518,7 @@ void main() {
       expect(
           packageGraph
               .localPackages.first.defaultCategory.publicLibraries.length,
-          equals(8));
+          equals(9));
     });
   });
 
@@ -588,7 +588,7 @@ void main() {
       });
 
       test('libraries', () {
-        expect(packageGraph.localPublicLibraries, hasLength(13));
+        expect(packageGraph.localPublicLibraries, hasLength(14));
         expect(interceptorsLib.isPublic, isFalse);
       });
 
@@ -603,7 +603,7 @@ void main() {
 
         Package package = packageGraph.localPackages.first;
         expect(package.name, 'test_package');
-        expect(package.publicLibraries, hasLength(13));
+        expect(package.publicLibraries, hasLength(14));
       });
 
       test('multiple packages, sorted default', () {
@@ -696,7 +696,8 @@ void main() {
         // If EventTarget really does start implementing hashCode, this will
         // fail.
         expect(hashCode.href, equals('dart-core/Object/hashCode.html'));
-        expect(hashCode.canonicalEnclosingContainer, equals(objectModelElement));
+        expect(
+            hashCode.canonicalEnclosingContainer, equals(objectModelElement));
         expect(
             EventTarget.publicSuperChainReversed
                 .any((et) => et.name == 'Interceptor'),
@@ -720,13 +721,17 @@ void main() {
         isDeprecated,
         someLib,
         reexportOneLib,
-        reexportTwoLib;
-    Class SomeClass, SomeOtherClass, YetAnotherClass, AUnicornClass;
+        reexportTwoLib,
+        reexportThreeLib;
+    Class SomeClass,
+        SomeOtherClass,
+        YetAnotherClass,
+        AUnicornClass,
+        ADuplicateClass;
 
     setUpAll(() {
       dartAsyncLib = utils.testPackageGraphSdk.libraries
           .firstWhere((l) => l.name == 'dart:async');
-
       anonLib = packageGraph.libraries
           .firstWhere((lib) => lib.name == 'anonymous_library');
 
@@ -736,10 +741,13 @@ void main() {
           .firstWhere((lib) => lib.name == 'reexport_one');
       reexportTwoLib = packageGraph.libraries
           .firstWhere((lib) => lib.name == 'reexport_two');
+      reexportThreeLib = packageGraph.libraries
+          .firstWhere((lib) => lib.name == 'reexport_three');
       SomeClass = someLib.getClassByName('SomeClass');
       SomeOtherClass = someLib.getClassByName('SomeOtherClass');
       YetAnotherClass = someLib.getClassByName('YetAnotherClass');
       AUnicornClass = someLib.getClassByName('AUnicornClass');
+      ADuplicateClass = reexportThreeLib.getClassByName('ADuplicateClass');
 
       isDeprecated = packageGraph.libraries
           .firstWhere((lib) => lib.name == 'is_deprecated');
@@ -871,6 +879,10 @@ void main() {
       expect(SomeOtherClass.canonicalLibrary, reexportOneLib);
       expect(SomeClass.canonicalLibrary, reexportTwoLib);
     });
+
+    test('with correct show/hide behavior', () {
+      expect(ADuplicateClass.definingLibrary.name, equals('shadowing_lib'));
+    });
   });
 
   group('Macros', () {
@@ -2125,40 +2137,62 @@ void main() {
           .firstWhere((lib) => lib.name == 'reexport_one');
       reexportTwoLib = packageGraph.libraries
           .firstWhere((lib) => lib.name == 'reexport_two');
-      documentOnceReexportOne = reexportOneLib.extensions.firstWhere((e) => e.name == 'DocumentThisExtensionOnce');
-      documentOnceReexportTwo = reexportTwoLib.extensions.firstWhere((e) => e.name == 'DocumentThisExtensionOnce');
+      documentOnceReexportOne = reexportOneLib.extensions
+          .firstWhere((e) => e.name == 'DocumentThisExtensionOnce');
+      documentOnceReexportTwo = reexportTwoLib.extensions
+          .firstWhere((e) => e.name == 'DocumentThisExtensionOnce');
 
       ext = exLibrary.extensions.firstWhere((e) => e.name == 'AppleExtension');
-      extensionReferencer = exLibrary.classes.firstWhere((c) => c.name == 'ExtensionReferencer');
+      extensionReferencer =
+          exLibrary.classes.firstWhere((c) => c.name == 'ExtensionReferencer');
       fancyList = exLibrary.extensions.firstWhere((e) => e.name == 'FancyList');
-      doSomeStuff = exLibrary.classes.firstWhere((c) => c.name == 'ExtensionUser')
-          .allInstanceMethods.firstWhere((m) => m.name == 'doSomeStuff');
-      doStuff = exLibrary.extensions.firstWhere((e) => e.name == 'SimpleStringExtension')
-          .instanceMethods.firstWhere((m) => m.name == 'doStuff');
+      doSomeStuff = exLibrary.classes
+          .firstWhere((c) => c.name == 'ExtensionUser')
+          .allInstanceMethods
+          .firstWhere((m) => m.name == 'doSomeStuff');
+      doStuff = exLibrary.extensions
+          .firstWhere((e) => e.name == 'SimpleStringExtension')
+          .instanceMethods
+          .firstWhere((m) => m.name == 'doStuff');
       extensions = exLibrary.publicExtensions.toList();
     });
 
     test('basic canonicalization for extensions', () {
       expect(documentOnceReexportOne.isCanonical, isFalse);
-      expect(documentOnceReexportOne.href, equals(documentOnceReexportTwo.href));
+      expect(
+          documentOnceReexportOne.href, equals(documentOnceReexportTwo.href));
       expect(documentOnceReexportTwo.isCanonical, isTrue);
     });
 
     // TODO(jcollins-g): implement feature and update tests
     test('documentation links do not crash in base cases', () {
-      packageGraph.packageWarningCounter.hasWarning(doStuff, PackageWarning.notImplemented,
+
+      packageGraph.packageWarningCounter.hasWarning(
+          doStuff,
+          PackageWarning.notImplemented,
           'Comment reference resolution inside extension methods is not yet implemented');
-      packageGraph.packageWarningCounter.hasWarning(doSomeStuff, PackageWarning.notImplemented,
+      packageGraph.packageWarningCounter.hasWarning(
+          doSomeStuff,
+          PackageWarning.notImplemented,
           'Comment reference resolution inside extension methods is not yet implemented');
       expect(doStuff.documentationAsHtml, contains('<code>another</code>'));
-      expect(doSomeStuff.documentationAsHtml, contains('<code>String.extensionNumber</code>'));
+      expect(doSomeStuff.documentationAsHtml,
+          contains('<code>String.extensionNumber</code>'));
     });
 
-    test('references from outside an extension refer correctly to the extension', () {
-      expect(extensionReferencer.documentationAsHtml, contains('<code>_Shhh</code>'));
-      expect(extensionReferencer.documentationAsHtml, contains('<a href="ex/FancyList.html">FancyList</a>'));
-      expect(extensionReferencer.documentationAsHtml, contains('<a href="ex/AnExtension/call.html">AnExtension.call</a>'));
-      expect(extensionReferencer.documentationAsHtml, contains('<a href="reexport_two/DocumentThisExtensionOnce.html">DocumentThisExtensionOnce</a>'));
+    test(
+        'references from outside an extension refer correctly to the extension',
+        () {
+      expect(extensionReferencer.documentationAsHtml,
+          contains('<code>_Shhh</code>'));
+      expect(extensionReferencer.documentationAsHtml,
+          contains('<a href="ex/FancyList.html">FancyList</a>'));
+      expect(extensionReferencer.documentationAsHtml,
+          contains('<a href="ex/AnExtension/call.html">AnExtension.call</a>'));
+      expect(
+          extensionReferencer.documentationAsHtml,
+          contains(
+              '<a href="reexport_two/DocumentThisExtensionOnce.html">DocumentThisExtensionOnce</a>'));
     });
 
     test('has a fully qualified name', () {
@@ -2190,10 +2224,8 @@ void main() {
     });
 
     test('extended type has generics', () {
-      expect(
-          fancyList.extendedType.nameWithGenerics,
-          equals(
-              'List&lt;<wbr><span class="type-parameter">Z</span>&gt;'));
+      expect(fancyList.extendedType.nameWithGenerics,
+          equals('List&lt;<wbr><span class="type-parameter">Z</span>&gt;'));
     });
 
     test('get methods', () {
@@ -2231,7 +2263,8 @@ void main() {
 
     setUpAll(() {
       animal = exLibrary.enums.firstWhere((e) => e.name == 'Animal');
-      animalToString = animal.allInstanceMethods.firstWhere((m) => m.name == 'toString');
+      animalToString =
+          animal.allInstanceMethods.firstWhere((m) => m.name == 'toString');
 
       /// Trigger code reference resolution
       animal.documentationAsHtml;
@@ -2876,11 +2909,11 @@ String topLevelFunction(int param1, bool param2, Cool coolBeans,
     });
 
     test('Fields always have line and column information', () {
-        expect(implicitGetterExplicitSetter.characterLocation, isNotNull);
-        expect(explicitGetterImplicitSetter.characterLocation, isNotNull);
-        expect(explicitGetterSetter.characterLocation, isNotNull);
-        expect(constField.characterLocation, isNotNull);
-        expect(aProperty.characterLocation, isNotNull);
+      expect(implicitGetterExplicitSetter.characterLocation, isNotNull);
+      expect(explicitGetterImplicitSetter.characterLocation, isNotNull);
+      expect(explicitGetterSetter.characterLocation, isNotNull);
+      expect(constField.characterLocation, isNotNull);
+      expect(aProperty.characterLocation, isNotNull);
     });
 
     test('covariant fields are recognized', () {
@@ -3387,7 +3420,10 @@ String topLevelFunction(int param1, bool param2, Cool coolBeans,
     Constructor appleConstructorFromString;
     Constructor constructorTesterDefault, constructorTesterFromSomething;
     Constructor syntheticConstructor;
-    Class apple, constCat, constructorTester, referToADefaultConstructor,
+    Class apple,
+        constCat,
+        constructorTester,
+        referToADefaultConstructor,
         withSyntheticConstructor;
     setUpAll(() {
       apple = exLibrary.classes.firstWhere((c) => c.name == 'Apple');
@@ -3405,7 +3441,8 @@ String topLevelFunction(int param1, bool param2, Cool coolBeans,
           .firstWhere((c) => c.name == 'ConstructorTester.fromSomething');
       referToADefaultConstructor = fakeLibrary.classes
           .firstWhere((c) => c.name == 'ReferToADefaultConstructor');
-      withSyntheticConstructor = exLibrary.classes.firstWhere((c) => c.name == 'WithSyntheticConstructor');
+      withSyntheticConstructor = exLibrary.classes
+          .firstWhere((c) => c.name == 'WithSyntheticConstructor');
       syntheticConstructor = withSyntheticConstructor.defaultConstructor;
     });
 
diff --git a/testing/test_package/lib/reexport_three.dart b/testing/test_package/lib/reexport_three.dart
new file mode 100644
index 0000000000..10e4b1a399
--- /dev/null
+++ b/testing/test_package/lib/reexport_three.dart
@@ -0,0 +1,6 @@
+library reexport_three;
+
+// Test show/hide handling.
+export 'src/shadowing_lib.dart' show ADuplicateClass;
+// ignore: directives_ordering
+export 'src/shadow_lib.dart' hide ADuplicateClass;
diff --git a/testing/test_package/lib/reexport_two.dart b/testing/test_package/lib/reexport_two.dart
index e922e8aed6..d69e151bdb 100644
--- a/testing/test_package/lib/reexport_two.dart
+++ b/testing/test_package/lib/reexport_two.dart
@@ -5,6 +5,6 @@
 /// {@category Unreal}
 library reexport_two;
 
-export 'src/somelib.dart';
-
+// Intentionally create some duplicates via reexporting.
 export 'src/mixins.dart' show MixedIn, AMixin;
+export 'src/somelib.dart';
diff --git a/testing/test_package/lib/src/shadow_lib.dart b/testing/test_package/lib/src/shadow_lib.dart
new file mode 100644
index 0000000000..8afe83d6aa
--- /dev/null
+++ b/testing/test_package/lib/src/shadow_lib.dart
@@ -0,0 +1,7 @@
+library shadow_lib;
+
+class ADuplicateClass {
+  bool get aCompletelyDifferentGetter => true;
+}
+
+class SomeOtherClass {}
diff --git a/testing/test_package/lib/src/shadowing_lib.dart b/testing/test_package/lib/src/shadowing_lib.dart
new file mode 100644
index 0000000000..4e728dc58f
--- /dev/null
+++ b/testing/test_package/lib/src/shadowing_lib.dart
@@ -0,0 +1,7 @@
+library shadowing_lib;
+
+class ADuplicateClass {
+  bool get aGetter => true;
+}
+
+class SomeMoreClassDeclaration {}
\ No newline at end of file
diff --git a/testing/test_package/lib/src/somelib.dart b/testing/test_package/lib/src/somelib.dart
index 075745e6f5..697ec1f2b6 100644
--- a/testing/test_package/lib/src/somelib.dart
+++ b/testing/test_package/lib/src/somelib.dart
@@ -8,7 +8,6 @@ class YetAnotherClass {}
 
 class AUnicornClass {}
 
-
 /// A private extension.
 extension _Unseen on Object {
   void doYouSeeMe() { }