From 230ffe1a18057e682c76e57241a85683b7d0e637 Mon Sep 17 00:00:00 2001
From: Jordan Harband <ljharb@gmail.com>
Date: Sun, 5 Sep 2021 09:15:00 -0700
Subject: [PATCH] [Fix] `prefer-read-only-props`: avoid crash from #3064

See #3068
---
 lib/rules/prefer-read-only-props.js       |  2 +-
 tests/lib/rules/prefer-read-only-props.js | 37 +++++++++++++++++++++--
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/lib/rules/prefer-read-only-props.js b/lib/rules/prefer-read-only-props.js
index 028cf304cb..d97df5af67 100644
--- a/lib/rules/prefer-read-only-props.js
+++ b/lib/rules/prefer-read-only-props.js
@@ -51,7 +51,7 @@ module.exports = {
         Object.keys(component.declaredPropTypes).forEach((propName) => {
           const prop = component.declaredPropTypes[propName];
 
-          if (!isFlowPropertyType(prop.node)) {
+          if (!prop.node || !isFlowPropertyType(prop.node)) {
             return;
           }
 
diff --git a/tests/lib/rules/prefer-read-only-props.js b/tests/lib/rules/prefer-read-only-props.js
index b6e66dfeed..4f27fce90c 100644
--- a/tests/lib/rules/prefer-read-only-props.js
+++ b/tests/lib/rules/prefer-read-only-props.js
@@ -29,7 +29,7 @@ const parserOptions = {
 const ruleTester = new RuleTester({parserOptions});
 ruleTester.run('prefer-read-only-props', rule, {
 
-  valid: [
+  valid: [].concat(
     {
       // Class component with type parameter
       code: `
@@ -162,8 +162,39 @@ ruleTester.run('prefer-read-only-props', rule, {
         }
       `,
       parser: parsers.BABEL_ESLINT
-    }
-  ],
+    },
+    parsers.TS([{
+      code: `
+        import React from "react";
+
+        interface Props {
+          name: string;
+        }
+        
+        const MyComponent: React.FC<Props> = ({ name }) => {
+          return <div>{name}</div>;
+        };
+        
+        export default MyComponent;
+      `,
+      parser: parsers.TYPESCRIPT_ESLINT
+    }, {
+      code: `
+        import React from "react";
+
+        interface Props {
+          name: string;
+        }
+        
+        const MyComponent: React.FC<Props> = ({ name }) => {
+          return <div>{name}</div>;
+        };
+        
+        export default MyComponent;
+      `,
+      parser: parsers['@TYPESCRIPT_ESLINT']
+    }])
+  ),
 
   invalid: [
     {