Use arrow function to get actual this

packages/enzyme-adapter-react-16/src/ReactSixteenAdapter.js

@@ -247,7 +247,7 @@ function childrenToTree(node) {
   return flatten(children.map(toTree));
 }
 
-function nodeToHostNode(_node, supportsArray = false) {
+function nodeToHostNode(_node) {
   // NOTE(lmr): node could be a function component
   // which wont have an instance prop, but we can get the
   // host node associated with its return value at that point.
@@ -266,20 +266,13 @@ function nodeToHostNode(_node, supportsArray = false) {
     if (item && item.instance) return ReactDOM.findDOMNode(item.instance);
     return null;
   };
-
-  let nodes;
   if (Array.isArray(node)) {
-    nodes = node.map(mapper);
-  } else if (Array.isArray(node.rendered) && node.nodeType === 'class') {
-    nodes = node.rendered.map(mapper);
-  } else {
-    nodes = mapper(node);
+    return node.map(mapper);
   }
-
-  if (Array.isArray(nodes) && !supportsArray) {
-    return nodes[0];
+  if (Array.isArray(node.rendered) && node.nodeType === 'class') {
+    return node.rendered.map(mapper);
   }
-  return nodes;
+  return mapper(node);
 }
 
 const eventOptions = {
@@ -428,13 +421,13 @@ class ReactSixteenAdapter extends EnzymeAdapter {
           is166 ? catchingType : undefined,
         );
       },
-      simulateEvent(node, event, mock) {
+      simulateEvent: (node, event, mock) => {
         const mappedEvent = mapNativeEventNames(event, eventOptions);
         const eventFn = TestUtils.Simulate[mappedEvent];
         if (!eventFn) {
           throw new TypeError(`ReactWrapper::simulate() event '${event}' does not exist`);
         }
-        eventFn(nodeToHostNode(node), mock);
+        eventFn(this.nodeToHostNode(node), mock);
       },
       batchedUpdates(fn) {
         return fn();
@@ -662,7 +655,11 @@ class ReactSixteenAdapter extends EnzymeAdapter {
   }
 
   nodeToHostNode(node, supportsArray = false) {
-    return nodeToHostNode(node, supportsArray);
+    const nodes = nodeToHostNode(node);
+    if (Array.isArray(nodes) && !supportsArray) {
+      return nodes[0];
+    }
+    return nodes;
   }
 
   displayNameOfNode(node) {