Make mixins appear with reexports (#1786)

* Make mixins appear with reexports

* Rebuild test package docs

Author: jcollins-g

lib/src/model.dart

@@ -440,9 +440,11 @@ class Mixin extends Class {
       _inheritanceChain.add(this);
 
       // Mix-in interfaces come before other interfaces.
-      _inheritanceChain.addAll(superclassConstraints.expand(
-          (ParameterizedElementType i) =>
-              (i.element as Class).inheritanceChain));
+      _inheritanceChain.addAll(superclassConstraints
+          .expand((ParameterizedElementType i) =>
+              (i.element as Class).inheritanceChain)
+          .where((Class c) =>
+              c != packageGraph.specialClasses[SpecialClass.object]));
 
       // Interfaces need to come last, because classes in the superChain might
       // implement them even when they aren't mentioned.
@@ -2151,9 +2153,13 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
   @override
   List<Mixin> get mixins {
     if (_mixins != null) return _mixins;
-    List<MixinElementImpl> mixinClasses = [];
-    mixinClasses.addAll(
-        _exportedNamespace.definedNames.values.whereType<MixinElementImpl>());
+
+    /// 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) => new ModelElement.from(e, this, packageGraph) as Mixin)
         .toList(growable: false)
@@ -2302,7 +2308,7 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
     }
 
     types.addAll(_exportedNamespace.definedNames.values
-        .where((e) => e is ClassElement && e is! MixinElementImpl)
+        .where((e) => e is ClassElement && !e.isMixin)
         .cast<ClassElement>()
         .where((element) => !element.isEnum));
 
@@ -2311,6 +2317,7 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
         .toList(growable: false)
           ..sort(byName);
 
+    assert(!_classes.any((Class c) => c is Mixin));
     return _classes;
   }
 

test/model_test.dart

@@ -543,6 +543,11 @@ void main() {
       expect(exLibrary.hasPublicExceptions, isTrue);
     });
 
+    test('has mixins', () {
+      expect(fakeLibrary.hasPublicMixins, isTrue);
+      expect(reexportTwoLib.hasPublicMixins, isTrue);
+    });
+
     test('has enums', () {
       expect(exLibrary.hasPublicEnums, isTrue);
     });
@@ -1204,7 +1209,8 @@ void main() {
     test('doc comment inherited from getter', () {
       Field getterWithDocs = subForDocComments.instanceProperties
           .firstWhere((m) => m.name == 'getterWithDocs');
-      expect(getterWithDocs.documentationAsHtml, contains('Some really great topics.'));
+      expect(getterWithDocs.documentationAsHtml,
+          contains('Some really great topics.'));
     });
 
     test(

testing/test_package/lib/reexport_two.dart

@@ -5,3 +5,5 @@
 library reexport_two;
 
 export 'src/somelib.dart';
+
+export 'src/mixins.dart' show MixedIn, AMixin;

testing/test_package/lib/src/mixins.dart

@@ -0,0 +1,3 @@
+library mixins;
+
+export 'mixins_base.dart';

testing/test_package/lib/src/mixins_base.dart

@@ -0,0 +1,11 @@
+library mixins_base;
+
+mixin AMixin {}
+
+class ThisClass {
+  String property;
+}
+
+/// A class that extends another class with a new-style mixin, then is
+/// reexported a couple of times similar to how Flutter does things.
+class MixedIn extends ThisClass with AMixin {}

testing/test_package_docs/index.json

@@ -9620,6 +9620,83 @@
   "type": "library",
   "overriddenDepth": 0
  },
+ {
+  "name": "AMixin",
+  "qualifiedName": "reexport_two.AMixin",
+  "href": "reexport_two/AMixin/AMixin.html",
+  "type": "constructor",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "AMixin",
+   "type": "mixin"
+  }
+ },
+ {
+  "name": "AMixin",
+  "qualifiedName": "reexport_two.AMixin",
+  "href": "reexport_two/AMixin-mixin.html",
+  "type": "mixin",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "reexport_two",
+   "type": "library"
+  }
+ },
+ {
+  "name": "operator ==",
+  "qualifiedName": "reexport_two.AMixin.==",
+  "href": "reexport_two/AMixin/operator_equals.html",
+  "type": "method",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "AMixin",
+   "type": "mixin"
+  }
+ },
+ {
+  "name": "hashCode",
+  "qualifiedName": "reexport_two.AMixin.hashCode",
+  "href": "reexport_two/AMixin/hashCode.html",
+  "type": "property",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "AMixin",
+   "type": "mixin"
+  }
+ },
+ {
+  "name": "noSuchMethod",
+  "qualifiedName": "reexport_two.AMixin.noSuchMethod",
+  "href": "reexport_two/AMixin/noSuchMethod.html",
+  "type": "method",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "AMixin",
+   "type": "mixin"
+  }
+ },
+ {
+  "name": "runtimeType",
+  "qualifiedName": "reexport_two.AMixin.runtimeType",
+  "href": "reexport_two/AMixin/runtimeType.html",
+  "type": "property",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "AMixin",
+   "type": "mixin"
+  }
+ },
+ {
+  "name": "toString",
+  "qualifiedName": "reexport_two.AMixin.toString",
+  "href": "reexport_two/AMixin/toString.html",
+  "type": "method",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "AMixin",
+   "type": "mixin"
+  }
+ },
  {
   "name": "AUnicornClass",
   "qualifiedName": "reexport_two.AUnicornClass",
@@ -9697,6 +9774,39 @@
    "type": "class"
   }
  },
+ {
+  "name": "MixedIn",
+  "qualifiedName": "reexport_two.MixedIn",
+  "href": "reexport_two/MixedIn-class.html",
+  "type": "class",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "reexport_two",
+   "type": "library"
+  }
+ },
+ {
+  "name": "MixedIn",
+  "qualifiedName": "reexport_two.MixedIn",
+  "href": "reexport_two/MixedIn/MixedIn.html",
+  "type": "constructor",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "MixedIn",
+   "type": "class"
+  }
+ },
+ {
+  "name": "property",
+  "qualifiedName": "reexport_two.MixedIn.property",
+  "href": "reexport_two/MixedIn/property.html",
+  "type": "property",
+  "overriddenDepth": 0,
+  "enclosedBy": {
+   "name": "MixedIn",
+   "type": "class"
+  }
+ },
  {
   "name": "SomeClass",
   "qualifiedName": "reexport_two.SomeClass",