[Fix] display-name/component detection: avoid a crash on anonymous components

Fixes #2840.

Author: ljharb

CHANGELOG.md

@@ -10,6 +10,10 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 * [`jsx-newline`]: add new rule ([#2693][] @jzabala)
 * [`jsx-no-constructed-context-values`]: add new rule which checks when the value passed to a Context Provider will cause needless rerenders ([#2763][] @dylanOshima)
 
+### Fixed
+* [`display-name`]/component detection: avoid a crash on anonymous components ([#2840][] @ljharb)
+
+[#2840]: https://github.com/yannickcr/eslint-plugin-react/issues/2840
 [#2835]: https://github.com/yannickcr/eslint-plugin-react/pull/2835
 [#2763]: https://github.com/yannickcr/eslint-plugin-react/pull/2763
 [#2693]: https://github.com/yannickcr/eslint-plugin-react/pull/2693

lib/util/Components.js

@@ -577,7 +577,7 @@ function componentRule(rule, context) {
         return false;
       }).map((val) => {
         if (val.node.type === 'ArrowFunctionExpression') return val.node.parent.id.name;
-        return val.node.id.name;
+        return val.node.id && val.node.id.name;
       });
     },
 

tests/lib/rules/display-name.js

@@ -894,5 +894,32 @@ ruleTester.run('display-name', rule, {
     errors: [{
       message: 'Component definition is missing display name'
     }]
+  }, {
+    code: `
+      export default class extends React.PureComponent {
+        render() {
+          return <Card />;
+        }
+      }
+
+      const Card = (() => {
+        return React.memo(({ }) => (
+          <div />
+        ));
+      })();
+    `,
+    errors: [{
+      message: 'Component definition is missing display name',
+      line: 2,
+      column: 22,
+      endLine: 6,
+      endColumn: 8
+    }, {
+      message: 'Component definition is missing display name',
+      line: 9,
+      column: 16,
+      endLine: 11,
+      endColumn: 11
+    }]
   }]
 });