[Fix] display-name: fix false positive for HOF returning only nulls

Author: chiawendt

lib/util/Components.js

@@ -498,8 +498,13 @@ function componentRule(rule, context) {
           return undefined;
         }
 
-        // case: function any() { return (props) { return not-jsx-and-not-null } }
-        if (node.parent.type === 'ReturnStatement' && !utils.isReturningJSX(node) && !utils.isReturningOnlyNull(node)) {
+        // case: const any = () => { return (props) => null }
+        // case: const any = () => (props) => null
+        if (
+          (node.parent.type === 'ReturnStatement' || (node.parent.type === 'ArrowFunctionExpression' && node.parent.expression))
+          && !utils.isReturningJSX(node)
+          && !utils.isReturningOnlyNull(node)
+        ) {
           return undefined;
         }
 

tests/lib/rules/display-name.js

@@ -579,6 +579,15 @@ ruleTester.run('display-name', rule, {
         }
       `,
     },
+    {
+      // issue #3289
+      code: `
+        export const demo = (a) => (b) => {
+          if (a == null) return null;
+          return b;
+        }
+      `,
+    },
   ]),
 
   invalid: parsers.all([