From 9e64bf18e11828d6b4c0363bff5ed2eca1ccd838 Mon Sep 17 00:00:00 2001
From: Hristo Kanchev <hristokkanchev@gmail.com>
Date: Wed, 14 Aug 2019 15:44:06 +0200
Subject: [PATCH] [eslint-plugin-react-hooks] Fixed crash when referencing
 arguments in arrow functions. (#16356)

* Fixed issue with def being undefined while referencing arguments.

* Removed todo comment.

* Skip exhaustive deps check if def is null.

* Fixed code formatting in ExhaustiveDeps.

* Removed unneeded comment in ExhaustiveDeps.
---
 .../ESLintRuleExhaustiveDeps-test.js          | 22 +++++++++++++++++++
 .../src/ExhaustiveDeps.js                     | 13 ++++++-----
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/packages/eslint-plugin-react-hooks/__tests__/ESLintRuleExhaustiveDeps-test.js b/packages/eslint-plugin-react-hooks/__tests__/ESLintRuleExhaustiveDeps-test.js
index 72130f4b830a0..a9648151a2d77 100644
--- a/packages/eslint-plugin-react-hooks/__tests__/ESLintRuleExhaustiveDeps-test.js
+++ b/packages/eslint-plugin-react-hooks/__tests__/ESLintRuleExhaustiveDeps-test.js
@@ -1023,6 +1023,28 @@ const tests = {
         }
       `,
     },
+    // Ignore arguments keyword for arrow functions.
+    {
+      code: `
+        function Example() {
+          useEffect(() => {
+            arguments
+          }, [])
+        }
+      `,
+    },
+    {
+      code: `
+        function Example() {
+          useEffect(() => {
+            const bar = () => {
+              arguments;
+            };
+            bar();
+          }, [])
+        }
+      `,
+    },
   ],
   invalid: [
     {
diff --git a/packages/eslint-plugin-react-hooks/src/ExhaustiveDeps.js b/packages/eslint-plugin-react-hooks/src/ExhaustiveDeps.js
index 4a2c4f16ce335..37e315b429b3f 100644
--- a/packages/eslint-plugin-react-hooks/src/ExhaustiveDeps.js
+++ b/packages/eslint-plugin-react-hooks/src/ExhaustiveDeps.js
@@ -397,13 +397,14 @@ export default {
             });
           }
 
-          // Ignore references to the function itself as it's not defined yet.
           const def = reference.resolved.defs[0];
-          if (
-            def != null &&
-            def.node != null &&
-            def.node.init === node.parent
-          ) {
+
+          if (def == null) {
+            continue;
+          }
+
+          // Ignore references to the function itself as it's not defined yet.
+          if (def.node != null && def.node.init === node.parent) {
             continue;
           }