Expose meaningful $r as fallback for functions (#1281)

Author: gaearon

backend/attachRendererFiber.js

@@ -322,6 +322,7 @@ function attachRendererFiber(hook: Hook, rid: string, renderer: ReactRenderer):
         break;
       case HostText:
         nodeType = 'Text';
+        publicInstance = fiber.stateNode;
         text = fiber.memoizedProps;
         break;
       case Fragment:
@@ -456,6 +457,14 @@ function attachRendererFiber(hook: Hook, rid: string, renderer: ReactRenderer):
       treeBaseDuration = fiber.treeBaseDuration;
     }
 
+    if (publicInstance === null) {
+      // publicInstance is used for $r.
+      // If we have nothing useful to expose, at least give props and state.
+      // This is an escape hatch to avoid a situation where there is useful
+      // data in the tree but DevTools don't offer any way to get it through console.
+      publicInstance = { props, state, type };
+    }
+
     // $FlowFixMe
     return {
       nodeType,