From ccad8044eaad9505f6efb7ce28055a2c38befacd Mon Sep 17 00:00:00 2001
From: Kacper Wiszczuk <kacperwiszczuk@gmail.com>
Date: Tue, 19 Mar 2019 19:47:26 +0100
Subject: [PATCH] fix: check for undefined/null children (#136)

### Summary

Check for undefined/null values, in `getByText` nodes.

Fixes #135

### Test plan

Passing tests on repro repository https://github.com/wKovacs64/rntl-161-repro.

Have no idea how to create a unit test, to test this behavior.

cc @thymikee @wKovacs64
---
 src/helpers/getByAPI.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/helpers/getByAPI.js b/src/helpers/getByAPI.js
index 91b131a0..28685ff2 100644
--- a/src/helpers/getByAPI.js
+++ b/src/helpers/getByAPI.js
@@ -20,8 +20,10 @@ const getNodeByText = (node, text) => {
     const isTextComponent =
       filterNodeByType(node, Text) || filterNodeByType(node, TextInput);
     if (isTextComponent) {
-      const textChildren = React.Children.map(node.props.children, child =>
-        child.toString()
+      const textChildren = React.Children.map(
+        node.props.children,
+        // In some cases child might be undefined
+        child => (child ? child.toString() : '')
       );
       if (textChildren) {
         const textToTest = textChildren.join('');