From 9a4051476b71804095678225f0c305f354ee8e9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Antonio=20P=C3=A9rez=20Barrero?= <antonio.perez@devo.com>
Date: Tue, 12 Jul 2022 18:40:06 +0200
Subject: [PATCH] [Fix] display-name: fix false positive for assignment of
 function returning null

---
 lib/util/Components.js          | 9 +++++++++
 tests/lib/rules/display-name.js | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/lib/util/Components.js b/lib/util/Components.js
index b6114717c5..dec1143162 100644
--- a/lib/util/Components.js
+++ b/lib/util/Components.js
@@ -508,6 +508,15 @@ function componentRule(rule, context) {
           return undefined;
         }
 
+        // case: any = () => { return => null }
+        // case: any = () => null
+        if (node.parent.type === 'AssignmentExpression' && !isPropertyAssignment && utils.isReturningJSXOrNull(node)) {
+          if (isFirstLetterCapitalized(node.parent.left.name)) {
+            return node;
+          }
+          return undefined;
+        }
+
         // for case abc = { [someobject.somekey]: props => { ... return not-jsx } }
         if (node.parent && node.parent.key && node.parent.key.type === 'MemberExpression' && !utils.isReturningJSX(node) && !utils.isReturningOnlyNull(node)) {
           return undefined;
diff --git a/tests/lib/rules/display-name.js b/tests/lib/rules/display-name.js
index 445add83a5..39bdb59cb5 100644
--- a/tests/lib/rules/display-name.js
+++ b/tests/lib/rules/display-name.js
@@ -588,6 +588,15 @@ ruleTester.run('display-name', rule, {
         }
       `,
     },
+    {
+      // issue #3329
+      code: `
+        let demo = null;
+        demo = (a) => {
+          if (a == null) return null;
+          return f(a);
+        };`,
+    },
     {
       // issue #3303
       code: `