[Fix] no-unused-state: check for class expression

Fixes #2251

Author: jzabala

lib/rules/no-unused-state.js

@@ -219,12 +219,28 @@ module.exports = {
       }
     }
 
+    function handleES6ComponentEnter(node) {
+      if (utils.isES6Component(node)) {
+        classInfo = getInitialClassInfo();
+      }
+    }
+
+    function handleES6ComponentExit() {
+      if (!classInfo) {
+        return;
+      }
+      reportUnusedFields();
+      classInfo = null;
+    }
+
     return {
-      ClassDeclaration(node) {
-        if (utils.isES6Component(node)) {
-          classInfo = getInitialClassInfo();
-        }
-      },
+      ClassDeclaration: handleES6ComponentEnter,
+
+      'ClassDeclaration:exit': handleES6ComponentExit,
+
+      ClassExpression: handleES6ComponentEnter,
+
+      'ClassExpression:exit': handleES6ComponentExit,
 
       ObjectExpression(node) {
         if (utils.isES5Component(node)) {
@@ -243,14 +259,6 @@ module.exports = {
         }
       },
 
-      'ClassDeclaration:exit'() {
-        if (!classInfo) {
-          return;
-        }
-        reportUnusedFields();
-        classInfo = null;
-      },
-
       CallExpression(node) {
         if (!classInfo) {
           return;

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

@@ -1193,6 +1193,16 @@ eslintTester.run('no-unused-state', rule, {
       `,
       parser: parsers.BABEL_ESLINT,
       errors: getErrorMessages(['initial'])
+    }, {
+      code: `
+        wrap(class NotWorking extends React.Component {
+            state = {
+                dummy: null
+            };
+        });
+      `,
+      parser: parsers.BABEL_ESLINT,
+      errors: getErrorMessages(['dummy'])
     }, {
       code: `
       class Foo extends Component {