From 1fe2285f83e2a29d889fac2db941f2b1165f7bba Mon Sep 17 00:00:00 2001
From: Nikola Telkedzhiev <ntelkedzhiev@gmail.com>
Date: Thu, 26 Jul 2018 17:35:31 +0300
Subject: [PATCH] Throw if headerTransform is set but it is not a function

---
 papaparse.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/papaparse.js b/papaparse.js
index 1b8eb28..1b227f0 100755
--- a/papaparse.js
+++ b/papaparse.js
@@ -1113,8 +1113,12 @@
 						header = header.trim();
 					}
 
-					if (typeof _config.headerTransform === 'function') {
-						header = _config.headerTransform(header);
+					if (_config.headerTransform) {
+						if (typeof _config.headerTransform === 'function') {
+							header = _config.headerTransform(header);
+						} else {
+							throw 'headerTransform must be a function';
+						}	
 					}
 
 					_fields.push(header);