[Fix] jsx-max-depth: avoid crash with childless jsx child

Fixes #2869

CHANGELOG.md

@@ -16,9 +16,11 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 * [`jsx-no-target-blank`]: avoid a crash with a non-string literal ([#2851][] @ljharb)
 * [`jsx-no-script-url`]: avoid crash with boolean `href` ([#2871][] @ljharb, @AriPerkkio)
 * [`no-typos`]: avoid crash with computed method name ([#2870][] @ljharb, @AriPerkkio)
+* [`jsx-max-depth`]: avoid crash with childless jsx child ([#2869][] @ljharb, @AriPerkkio)
 
 [#2871]: https://github.com/yannickcr/eslint-plugin-react/issues/2871
 [#2870]: https://github.com/yannickcr/eslint-plugin-react/issues/2870
+[#2869]: https://github.com/yannickcr/eslint-plugin-react/issues/2869
 [#2851]: https://github.com/yannickcr/eslint-plugin-react/issues/2851
 [#2843]: https://github.com/yannickcr/eslint-plugin-react/pull/2843
 [#2840]: https://github.com/yannickcr/eslint-plugin-react/issues/2840

lib/rules/jsx-max-depth.js

@@ -52,7 +52,7 @@ module.exports = {
     function isLeaf(node) {
       const children = node.children;
 
-      return !children.length || !children.some(hasJSX);
+      return !children || children.length === 0 || !children.some(hasJSX);
     }
 
     function getDepth(node) {

tests/lib/rules/jsx-max-depth.js

@@ -107,6 +107,13 @@ ruleTester.run('jsx-max-depth', rule, {
       '};'
     ].join('\n'),
     options: [{max: 1}]
+  }, {
+    code: [
+      'export function MyComponent() {',
+      '  const A = <>{<div />}</>;',
+      '  return <div>{A}</div>;',
+      '}'
+    ].join('\n')
   }],
 
   invalid: [{