fix: check key exisits before accessing

Co-authored-by: Jordan Harband <[email protected]>

Author: HenryBrown0

lib/rules/function-component-definition.js

@@ -34,11 +34,11 @@ const UNNAMED_FUNCTION_TEMPLATES = {
 
 function hasOneUnconstrainedTypeParam(node) {
   const nodeTypeParams = node.typeParameters;
-  if (!nodeTypeParams) {
-    return false;
-  }
 
-  return nodeTypeParams.params.length === 1 && !nodeTypeParams.params[0].constraint;
+  return nodeTypeParams
+    && nodeTypeParams.params
+    && nodeTypeParams.params.length === 1
+    && !nodeTypeParams.params[0].constraint;
 }
 
 function hasName(node) {