From 6807e45e1eb507184d1da64f54684e26f6e5cf0c Mon Sep 17 00:00:00 2001
From: Adam Wathan <adam.wathan@gmail.com>
Date: Thu, 16 Nov 2017 07:51:56 -0500
Subject: [PATCH] Expect onError function is always provided

This can't really be optional.
---
 src/lib/substituteClassApplyAtRules.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/substituteClassApplyAtRules.js b/src/lib/substituteClassApplyAtRules.js
index ed5971d45..4bb3eb09a 100644
--- a/src/lib/substituteClassApplyAtRules.js
+++ b/src/lib/substituteClassApplyAtRules.js
@@ -23,7 +23,7 @@ function findMixin(css, mixin, onError) {
     }
   })
 
-  if (_.isEmpty(matches) && _.isFunction(onError)) {
+  if (_.isEmpty(matches)) {
     onError(`\`@apply\` cannot be used with ${mixin} because ${mixin} either does not exist, or it's actual definition includes a pseudo-class like :hover, :active, etc.`)
   }