From da7a0458d46d88ba33a81b8806edd94313077e29 Mon Sep 17 00:00:00 2001
From: Chiawen Chen <golopot@gmail.com>
Date: Sun, 8 Mar 2020 18:39:06 +0800
Subject: [PATCH] [Fix] `no-unused-state`: handle optional chaining

Fixes #2515
---
 lib/rules/no-unused-state.js                |  2 +-
 tests/helpers/parsers.js                    | 10 +++++++-
 tests/lib/rules/jsx-no-comment-textnodes.js | 13 ++---------
 tests/lib/rules/no-unused-state.js          | 26 +++++++++++++++++++--
 4 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/lib/rules/no-unused-state.js b/lib/rules/no-unused-state.js
index 05bc08b29a..e05ef73cd4 100644
--- a/lib/rules/no-unused-state.js
+++ b/lib/rules/no-unused-state.js
@@ -415,7 +415,7 @@ module.exports = {
         handleAssignment(node.id, node.init);
       },
 
-      MemberExpression(node) {
+      'MemberExpression, OptionalMemberExpression'(node) {
         if (!classInfo) {
           return;
         }
diff --git a/tests/helpers/parsers.js b/tests/helpers/parsers.js
index be4994e0e0..73b7a2248a 100644
--- a/tests/helpers/parsers.js
+++ b/tests/helpers/parsers.js
@@ -1,11 +1,19 @@
 'use strict';
 
 const path = require('path');
+const semver = require('semver');
+const version = require('eslint/package.json').version;
 
 const NODE_MODULES = '../../node_modules';
 
 module.exports = {
   BABEL_ESLINT: path.join(__dirname, NODE_MODULES, 'babel-eslint'),
   TYPESCRIPT_ESLINT: path.join(__dirname, NODE_MODULES, 'typescript-eslint-parser'),
-  '@TYPESCRIPT_ESLINT': path.join(__dirname, NODE_MODULES, '@typescript-eslint/parser')
+  '@TYPESCRIPT_ESLINT': path.join(__dirname, NODE_MODULES, '@typescript-eslint/parser'),
+  TS: function TS(tests) {
+    if (semver.satisfies(version, '>= 5')) {
+      return tests;
+    }
+    return [];
+  }
 };
diff --git a/tests/lib/rules/jsx-no-comment-textnodes.js b/tests/lib/rules/jsx-no-comment-textnodes.js
index a01f5de1e3..20fcd9171e 100644
--- a/tests/lib/rules/jsx-no-comment-textnodes.js
+++ b/tests/lib/rules/jsx-no-comment-textnodes.js
@@ -9,20 +9,11 @@
 // Requirements
 // ------------------------------------------------------------------------------
 
-const semver = require('semver');
-const version = require('eslint/package.json').version;
 const RuleTester = require('eslint').RuleTester;
 const rule = require('../../../lib/rules/jsx-no-comment-textnodes');
 
 const parsers = require('../../helpers/parsers');
 
-function TS(tests) {
-  if (semver.satisfies(version, '>= 5')) {
-    return tests;
-  }
-  return [];
-}
-
 const parserOptions = {
   ecmaVersion: 2018,
   sourceType: 'module',
@@ -182,7 +173,7 @@ ruleTester.run('jsx-no-comment-textnodes', rule, {
       code: '<pre>&#x2F;&#42; TODO: Write perfect code &#42;&#x2F;</pre>',
       parser: parsers.BABEL_ESLINT
     }
-  ].concat(TS([
+  ].concat(parsers.TS([
     {
       code: `
       class Comp1 extends Component {
@@ -388,7 +379,7 @@ ruleTester.run('jsx-no-comment-textnodes', rule, {
       parser: parsers.BABEL_ESLINT,
       errors: [{message: 'Comments inside children section of tag should be placed inside braces'}]
     }
-  ].concat(TS([
+  ].concat(parsers.TS([
     {
       code: `
       class Comp1 extends Component {
diff --git a/tests/lib/rules/no-unused-state.js b/tests/lib/rules/no-unused-state.js
index f6ded949bd..bc6b4caf55 100644
--- a/tests/lib/rules/no-unused-state.js
+++ b/tests/lib/rules/no-unused-state.js
@@ -25,7 +25,7 @@ function getErrorMessages(unusedFields) {
 }
 
 eslintTester.run('no-unused-state', rule, {
-  valid: [
+  valid: [].concat(
     `function StatelessFnUnaffectedTest(props) {
        return <SomeComponent foo={props.foo} />;
     };`,
@@ -231,6 +231,28 @@ eslintTester.run('no-unused-state', rule, {
           }
         }`,
       parser: parsers.BABEL_ESLINT
+    }, parsers.TS([{
+      code: `
+        class OptionalChaining extends React.Component {
+          constructor() {
+            this.state = { foo: 0 };
+          }
+          render() {
+            return <SomeComponent foo={this.state?.foo} />;
+          }
+        }`,
+      parser: parsers['@TYPESCRIPT_ESLINT']
+    }]), {
+      code: `
+        class OptionalChaining extends React.Component {
+          constructor() {
+            this.state = { foo: 0 };
+          }
+          render() {
+            return <SomeComponent foo={this.state?.foo} />;
+          }
+        }`,
+      parser: parsers.BABEL_ESLINT
     },
     `class VariableDeclarationTest extends React.Component {
         constructor() {
@@ -795,7 +817,7 @@ eslintTester.run('no-unused-state', rule, {
       `,
       parser: parsers.TYPESCRIPT_ESLINT
     }
-  ],
+  ),
 
   invalid: [
     {