From c044d048ad7be295d9e38500a8a0780a1f10b0d1 Mon Sep 17 00:00:00 2001
From: Jamie Talbot <jamie@jamietalbot.com>
Date: Fri, 2 Feb 2018 10:19:01 -0800
Subject: [PATCH] Warn during normalization when range offsets are not numbers.
 (#1578)

---
 packages/slate/src/models/range.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/packages/slate/src/models/range.js b/packages/slate/src/models/range.js
index 68fce7bd2..66ea2e957 100644
--- a/packages/slate/src/models/range.js
+++ b/packages/slate/src/models/range.js
@@ -675,6 +675,12 @@ class Range extends Record(DEFAULTS) {
     const range = this
     let { anchorKey, anchorOffset, focusKey, focusOffset, isBackward } = range
 
+    const anchorOffsetType = typeof anchorOffset
+    const focusOffsetType = typeof focusOffset
+    if (anchorOffsetType != 'number' || focusOffsetType != 'number') {
+      logger.warn(`The range offsets should be numbers, but they were of type "${anchorOffsetType}" and "${focusOffsetType}".`)
+    }
+
     // If the range is unset, make sure it is properly zeroed out.
     if (anchorKey == null || focusKey == null) {
       return range.merge({