Improve name generation for indexed expressions

pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart

Index: pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart
diff --git a/pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart b/pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart
index 1ba794a3ca9213d4fb41a93e3c1ce91b63040055..e1c881a4c07f5a9f3de3ae0cad73aef3d2f3013a 100644
--- a/pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart
+++ b/pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart
@@ -612,27 +612,48 @@ class DartEditBuilderImpl extends EditBuilderImpl implements DartEditBuilder {
   }
 
   String _getBaseNameFromExpression(Expression expression) {
-    String name = null;
-    // e as Type
     if (expression is AsExpression) {
-      AsExpression asExpression = expression as AsExpression;
-      expression = asExpression.expression;
+      return _getBaseNameFromExpression(expression.expression);
+    } else if (expression is ParenthesizedExpression) {
+      return _getBaseNameFromExpression(expression.expression);
+    }
+    return _getBaseNameFromUnwrappedExpression(expression);
+  }
+
+  String _getBaseNameFromLocationInParent(Expression expression) {
+    // value in named expression
+    if (expression.parent is NamedExpression) {
+      NamedExpression namedExpression = expression.parent as NamedExpression;
+      if (namedExpression.expression == expression) {
+        return namedExpression.name.label.name;
+      }
+    }
+    // positional argument
+    ParameterElement parameter = expression.propagatedParameterElement;
+    if (parameter == null) {
+      parameter = expression.staticParameterElement;
+    }
+    if (parameter != null) {
+      return parameter.displayName;
     }
+
+    // unknown
+    return null;
+  }
+
+  String _getBaseNameFromUnwrappedExpression(Expression expression) {
+    String name = null;
     // analyze expressions
     if (expression is SimpleIdentifier) {
-      SimpleIdentifier node = expression;
-      return node.name;
+      return expression.name;
     } else if (expression is PrefixedIdentifier) {
-      PrefixedIdentifier node = expression;
-      return node.identifier.name;
+      return expression.identifier.name;
     } else if (expression is PropertyAccess) {
-      PropertyAccess node = expression;
-      return node.propertyName.name;
+      return expression.propertyName.name;
     } else if (expression is MethodInvocation) {
       name = expression.methodName.name;
     } else if (expression is InstanceCreationExpression) {
-      InstanceCreationExpression creation = expression;
-      ConstructorName constructorName = creation.constructorName;
+      ConstructorName constructorName = expression.constructorName;
       TypeName typeName = constructorName.type;
       if (typeName != null) {
         Identifier typeNameIdentifier = typeName.name;
@@ -651,6 +672,13 @@ class DartEditBuilderImpl extends EditBuilderImpl implements DartEditBuilder {
           return prefixed.prefix.name;
         }
       }
+    } else if (expression is IndexExpression) {
+      name = _getBaseNameFromExpression(expression.realTarget);
+      if (name.endsWith('es')) {
+        name = name.substring(0, name.length - 2);
+      } else if (name.endsWith('s')) {
+        name = name.substring(0, name.length - 1);
+      }
     }
     // strip known prefixes
     if (name != null) {
@@ -669,27 +697,6 @@ class DartEditBuilderImpl extends EditBuilderImpl implements DartEditBuilder {
     return name;
   }
 
-  String _getBaseNameFromLocationInParent(Expression expression) {
-    // value in named expression
-    if (expression.parent is NamedExpression) {
-      NamedExpression namedExpression = expression.parent as NamedExpression;
-      if (namedExpression.expression == expression) {
-        return namedExpression.name.label.name;
-      }
-    }
-    // positional argument
-    ParameterElement parameter = expression.propagatedParameterElement;
-    if (parameter == null) {
-      parameter = expression.staticParameterElement;
-    }
-    if (parameter != null) {
-      return parameter.displayName;
-    }
-
-    // unknown
-    return null;
-  }
-
   /**
    * Returns all variants of names by removing leading words one by one.
    */