Fix setNodes when called with 'split' and a collapsed range (#4523)

* Fix setNodes when called with 'split' and a collapsed range

* Only bail if it's a non-empty text node

* Fix comment

.changeset/sharp-donkeys-sparkle.md

@@ -0,0 +1,5 @@
+---
+'slate': patch
+---
+
+Fix setNodes when called with 'split' and a collapsed range

packages/slate/src/interfaces/range.ts

@@ -222,12 +222,16 @@ export const Range: RangeInterface = {
       let affinityFocus: 'forward' | 'backward' | null
 
       if (affinity === 'inward') {
+        // If the range is collapsed, make sure to use the same affinity to
+        // avoid the two points passing each other and expanding in the opposite
+        // direction
+        const isCollapsed = Range.isCollapsed(r)
         if (Range.isForward(r)) {
           affinityAnchor = 'forward'
-          affinityFocus = 'backward'
+          affinityFocus = isCollapsed ? affinityAnchor : 'backward'
         } else {
           affinityAnchor = 'backward'
-          affinityFocus = 'forward'
+          affinityFocus = isCollapsed ? affinityAnchor : 'forward'
         }
       } else if (affinity === 'outward') {
         if (Range.isForward(r)) {

packages/slate/src/transforms/node.ts

@@ -594,6 +594,14 @@ export const NodeTransforms: NodeTransforms = {
       }
 
       if (split && Range.isRange(at)) {
+        if (
+          Range.isCollapsed(at) &&
+          Editor.leaf(editor, at.anchor)[0].text.length > 0
+        ) {
+          // If the range is collapsed in a non-empty node and 'split' is true, there's nothing to
+          // set that won't get normalized away
+          return
+        }
         const rangeRef = Editor.rangeRef(editor, at, { affinity: 'inward' })
         const [start, end] = Range.edges(at)
         const splitMode = mode === 'lowest' ? 'lowest' : 'highest'

packages/slate/test/interfaces/Range/transform/inward-collapsed.tsx

@@ -0,0 +1,34 @@
+import { Range } from 'slate'
+
+export const input = {
+  anchor: {
+    path: [0, 0],
+    offset: 1,
+  },
+  focus: {
+    path: [0, 0],
+    offset: 1,
+  },
+}
+export const test = value => {
+  return Range.transform(
+    value,
+    {
+      type: 'split_node',
+      path: [0, 0],
+      position: 1,
+      properties: {},
+    },
+    { affinity: 'inward' }
+  )
+}
+export const output = {
+  anchor: {
+    path: [0, 1],
+    offset: 0,
+  },
+  focus: {
+    path: [0, 1],
+    offset: 0,
+  },
+}

packages/slate/test/transforms/setNodes/split/noop-collapsed.tsx

@@ -0,0 +1,27 @@
+/** @jsx jsx */
+import { Transforms, Text } from 'slate'
+import { jsx } from '../../..'
+
+export const run = editor => {
+  Transforms.setNodes(
+    editor,
+    { someKey: true },
+    { match: Text.isText, split: true }
+  )
+}
+export const input = (
+  <editor>
+    <block>
+      w<cursor />
+      ord
+    </block>
+  </editor>
+)
+export const output = (
+  <editor>
+    <block>
+      w<cursor />
+      ord
+    </block>
+  </editor>
+)