Fix splitNode range updates when selection is backward (ianstormtaylo…

…r#2938)

packages/slate/src/models/value.js

@@ -799,16 +799,16 @@ class Value extends Record(DEFAULTS) {
 
     value = value.mapRanges(range => {
       const next = newDocument.getNextText(node.key)
-      const { start, end } = range
+      const { anchor, focus } = range
 
-      // If the start was after the split, move it to the next node.
-      if (node.key === start.key && position <= start.offset) {
-        range = range.moveStartTo(next.key, start.offset - position)
+      // If the anchor was after the split, move it to the next node.
+      if (node.key === anchor.key && position <= anchor.offset) {
+        range = range.moveAnchorTo(next.key, anchor.offset - position)
       }
 
-      // If the end was after the split, move it to the next node.
-      if (node.key === end.key && position <= end.offset) {
-        range = range.moveEndTo(next.key, end.offset - position)
+      // If the focus was after the split, move it to the next node.
+      if (node.key === focus.key && position <= focus.offset) {
+        range = range.moveFocusTo(next.key, focus.offset - position)
       }
 
       range = range.updatePoints(point => point.setPath(null))

packages/slate/test/commands/at-current-range/remove-mark/part-of-mark-backward.js

@@ -0,0 +1,30 @@
+/** @jsx h */
+
+import h from '../../../helpers/h'
+
+export default function(editor) {
+  editor.removeMark('bold')
+}
+
+export const input = (
+  <value>
+    <document>
+      <paragraph>
+        <b>
+          wor<focus />d<anchor />
+        </b>
+      </paragraph>
+    </document>
+  </value>
+)
+
+export const output = (
+  <value>
+    <document>
+      <paragraph>
+        <b>wor</b>
+        <focus />d<anchor />
+      </paragraph>
+    </document>
+  </value>
+)

packages/slate/test/commands/at-current-range/remove-mark/part-of-mark.js

@@ -0,0 +1,30 @@
+/** @jsx h */
+
+import h from '../../../helpers/h'
+
+export default function(editor) {
+  editor.removeMark('bold')
+}
+
+export const input = (
+  <value>
+    <document>
+      <paragraph>
+        <b>
+          wor<anchor />d<focus />
+        </b>
+      </paragraph>
+    </document>
+  </value>
+)
+
+export const output = (
+  <value>
+    <document>
+      <paragraph>
+        <b>wor</b>
+        <anchor />d<focus />
+      </paragraph>
+    </document>
+  </value>
+)