Add showing docs of overridden accessors [#1266] (#1297)

For methods, in case there's a method, which overrides another method,
and it doesn't have docs, we show the docs from the overridden method.

@Hixie noticed we don't do the same thing for accessors. He and
@devoncarew think we should do the same for accessors as well.

This commit adds that functionality.

Author: astashov

lib/src/model.dart

@@ -102,6 +102,22 @@ class Accessor extends ModelElement
 
   bool get isGetter => _accessor.isGetter;
 
+  @override
+  Accessor get overriddenElement {
+    Element parent = element.enclosingElement;
+    if (parent is ClassElement) {
+      for (InterfaceType t in getAllSupertypes(parent)) {
+        var accessor = this.isGetter
+            ? t.getGetter(element.name)
+            : t.getSetter(element.name);
+        if (accessor != null) {
+          return new Accessor(accessor, library);
+        }
+      }
+    }
+    return null;
+  }
+
   @override
   String get kind => 'accessor';
 
@@ -1548,7 +1564,7 @@ abstract class ModelElement implements Comparable, Nameable, Documentable {
     return __documentation;
   }
 
-  bool canOverride() => element is ClassMemberElement;
+  bool canOverride() => element is ClassMemberElement || element is PropertyAccessorElement;
 
   @override
   int compareTo(dynamic other) {

test/model_test.dart

@@ -1196,6 +1196,8 @@ String topLevelFunction(int param1, bool param2, Cool coolBeans,
         onlySetterGetter,
         onlySetterSetter;
 
+    Class classB;
+
     setUp(() {
       TopLevelVariable justGetter =
           fakeLibrary.properties.firstWhere((p) => p.name == 'justGetter');
@@ -1205,6 +1207,8 @@ String topLevelFunction(int param1, bool param2, Cool coolBeans,
           fakeLibrary.properties.firstWhere((p) => p.name == 'justSetter');
       onlySetterSetter = justSetter.setter;
       onlySetterGetter = justSetter.getter;
+
+      classB = exLibrary.classes.singleWhere((c) => c.name == 'B');
     });
 
     test('are available on top-level variables', () {
@@ -1213,6 +1217,11 @@ String topLevelFunction(int param1, bool param2, Cool coolBeans,
       expect(onlySetterGetter, isNull);
       expect(onlySetterSetter.name, equals('justSetter='));
     });
+
+    test('if overridden, gets documentation from superclasses', () {
+      final doc = classB.allInstanceProperties.firstWhere((p) => p.name == "s").getter.documentation;
+      expect(doc, equals("The getter for `s`"));
+    });
   });
 
   group('Top-level Variable', () {

testing/test_package/lib/example.dart

@@ -151,6 +151,9 @@ class B extends Apple with Cat {
   @override
   bool get isImplemented => false;
 
+  @override
+  String get s => "123";
+
   @deprecated
   Future doNothing() async {}
 

testing/test_package_docs/ex/B-class.html

@@ -239,6 +239,16 @@ <h2>Properties</h2>
           <div class="features">
     read-only, inherited
   </div>
+</dd>
+        <dt id="s" class="property">
+          <span class="name"><a href="ex/B/s.html">s</a></span>
+          <span class="signature">&#8594; String</span>
+        </dt>
+        <dd>
+          <p></p>
+          <div class="features">
+    read-only
+  </div>
 </dd>
         <dt id="s" class="property inherited">
           <span class="name"><a href="ex/Apple/s.html">s</a></span>
@@ -389,6 +399,7 @@ <h5>B</h5>
       <li><a href="ex/B/list.html">list</a></li>
       <li class="inherited"><a href="ex/Apple/m.html">m</a></li>
       <li class="inherited"><a href="ex/B/runtimeType.html">runtimeType</a></li>
+      <li><a href="ex/B/s.html">s</a></li>
       <li class="inherited"><a href="ex/Apple/s.html">s</a></li>
 
       <li class="section-title inherited"><a href="ex/B-class.html#operators">Operators</a></li>

testing/test_package_docs/ex/B/B.html

@@ -89,6 +89,7 @@ <h5><a href="ex/B-class.html">B</a></h5>
       <li><a href="ex/B/list.html">list</a></li>
       <li class="inherited"><a href="ex/Apple/m.html">m</a></li>
       <li class="inherited"><a href="ex/B/runtimeType.html">runtimeType</a></li>
+      <li><a href="ex/B/s.html">s</a></li>
       <li class="inherited"><a href="ex/Apple/s.html">s</a></li>
 
       <li class="section-title inherited"><a href="ex/B-class.html#operators">Operators</a></li>

testing/test_package_docs/ex/B/abstractMethod.html

@@ -88,6 +88,7 @@ <h5><a href="ex/B-class.html">B</a></h5>
       <li><a href="ex/B/list.html">list</a></li>
       <li class="inherited"><a href="ex/Apple/m.html">m</a></li>
       <li class="inherited"><a href="ex/B/runtimeType.html">runtimeType</a></li>
+      <li><a href="ex/B/s.html">s</a></li>
       <li class="inherited"><a href="ex/Apple/s.html">s</a></li>
 
       <li class="section-title inherited"><a href="ex/B-class.html#operators">Operators</a></li>

testing/test_package_docs/ex/B/autoCompress.html

@@ -88,6 +88,7 @@ <h5><a href="ex/B-class.html">B</a></h5>
       <li><a href="ex/B/list.html">list</a></li>
       <li class="inherited"><a href="ex/Apple/m.html">m</a></li>
       <li class="inherited"><a href="ex/B/runtimeType.html">runtimeType</a></li>
+      <li><a href="ex/B/s.html">s</a></li>
       <li class="inherited"><a href="ex/Apple/s.html">s</a></li>
 
       <li class="section-title inherited"><a href="ex/B-class.html#operators">Operators</a></li>

testing/test_package_docs/ex/B/doNothing.html

@@ -88,6 +88,7 @@ <h5><a href="ex/B-class.html">B</a></h5>
       <li><a href="ex/B/list.html">list</a></li>
       <li class="inherited"><a href="ex/Apple/m.html">m</a></li>
       <li class="inherited"><a href="ex/B/runtimeType.html">runtimeType</a></li>
+      <li><a href="ex/B/s.html">s</a></li>
       <li class="inherited"><a href="ex/Apple/s.html">s</a></li>
 
       <li class="section-title inherited"><a href="ex/B-class.html#operators">Operators</a></li>

testing/test_package_docs/ex/B/hashCode.html

@@ -88,6 +88,7 @@ <h5><a href="ex/B-class.html">B</a></h5>
       <li><a href="ex/B/list.html">list</a></li>
       <li class="inherited"><a href="ex/Apple/m.html">m</a></li>
       <li class="inherited"><a href="ex/B/runtimeType.html">runtimeType</a></li>
+      <li><a href="ex/B/s.html">s</a></li>
       <li class="inherited"><a href="ex/Apple/s.html">s</a></li>
 
       <li class="section-title inherited"><a href="ex/B-class.html#operators">Operators</a></li>

testing/test_package_docs/ex/B/isImplemented.html

@@ -88,6 +88,7 @@ <h5><a href="ex/B-class.html">B</a></h5>
       <li><a href="ex/B/list.html">list</a></li>
       <li class="inherited"><a href="ex/Apple/m.html">m</a></li>
       <li class="inherited"><a href="ex/B/runtimeType.html">runtimeType</a></li>
+      <li><a href="ex/B/s.html">s</a></li>
       <li class="inherited"><a href="ex/Apple/s.html">s</a></li>
 
       <li class="section-title inherited"><a href="ex/B-class.html#operators">Operators</a></li>