Fix no-unused-state to detect usage of this.state as an object (fixes #1572)

Author: yannickcr

lib/rules/no-unused-state.js

@@ -352,6 +352,9 @@ module.exports = {
           }
           // Otherwise, record that we saw this property being accessed.
           addUsedStateField(node.property);
+        // If we see a `this.state` access in a CallExpression, give up.
+        } else if (isStateReference(node) && node.parent.type === 'CallExpression') {
+          classInfo = null;
         }
       },
 

tests/lib/rules/no-unused-state.js

@@ -479,6 +479,18 @@ eslintTester.run('no-unused-state', rule, {
         }
       }`,
       parser: 'babel-eslint'
+    },
+    {
+      code: `class ThisStateAsAnObject extends React.Component {
+        state = {
+          active: true
+        };
+
+        render() {
+          return <div className={classNames('overflowEdgeIndicator', className, this.state)} />;
+        }
+      }`,
+      parser: 'babel-eslint'
     }
   ],