From bbfb53f24839556ee25e6605acbd7e2947f81862 Mon Sep 17 00:00:00 2001
From: Jed Fox <git@twopointzero.us>
Date: Sat, 26 Aug 2017 18:35:09 -0400
Subject: [PATCH] !

---
 lib/rule-context.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/rule-context.js b/lib/rule-context.js
index 209fedde5cd3..d1530ec7320e 100644
--- a/lib/rule-context.js
+++ b/lib/rule-context.js
@@ -196,7 +196,7 @@ class RuleContext {
                 if (descriptor.message) {
                     throw new TypeError("context.report() called with a message and a messageId. Please only pass one.");
                 }
-                if (!messages || Object.prototype.hasOwnProperty.call(messages, id)) {
+                if (!messages || !Object.prototype.hasOwnProperty.call(messages, id)) {
                     throw new TypeError(`context.report() called with a messageId of '${id}' which is not present in the 'messages' config: ${JSON.stringify(messages, null, 2)}`);
                 }