Handle sibling moves in moveNodes transform (#3978)

* Handle sibling moves better in move nodes.

packages/slate/src/transforms/node.ts

@@ -487,6 +487,17 @@ export const NodeTransforms: NodeTransforms = {
         if (path.length !== 0) {
           editor.apply({ type: 'move_node', path, newPath })
         }
+
+        if (
+          toRef.current &&
+          Path.isSibling(newPath, path) &&
+          Path.isAfter(newPath, path)
+        ) {
+          // When performing a sibling move to a later index, the path at the destination is shifted
+          // to before the insertion point instead of after. To ensure our group of nodes are inserted
+          // in the correct order we increment toRef to account for that
+          toRef.current = Path.next(toRef.current)
+        }
       }
 
       toRef.unref()

packages/slate/test/transforms/moveNodes/selection/block-siblings-after.tsx

@@ -0,0 +1,37 @@
+/** @jsx jsx */
+import { Editor, Transforms } from 'slate'
+import { jsx } from '../../..'
+
+export const run = editor => {
+  Transforms.moveNodes(editor, {
+    match: n => Editor.isBlock(editor, n),
+    to: [2],
+  })
+}
+export const input = (
+  <editor>
+    <block>
+      <anchor />
+      one
+    </block>
+    <block>
+      two
+      <focus />
+    </block>
+    <block>three</block>
+  </editor>
+)
+
+export const output = (
+  <editor>
+    <block>three</block>
+    <block>
+      <anchor />
+      one
+    </block>
+    <block>
+      two
+      <focus />
+    </block>
+  </editor>
+)

packages/slate/test/transforms/moveNodes/selection/block-siblings-before.tsx

@@ -0,0 +1,37 @@
+/** @jsx jsx */
+import { Editor, Transforms } from 'slate'
+import { jsx } from '../../..'
+
+export const run = editor => {
+  Transforms.moveNodes(editor, {
+    match: n => Editor.isBlock(editor, n),
+    to: [0],
+  })
+}
+export const input = (
+  <editor>
+    <block>one</block>
+    <block>
+      two
+      <anchor />
+    </block>
+    <block>
+      three
+      <focus />
+    </block>
+  </editor>
+)
+
+export const output = (
+  <editor>
+    <block>
+      two
+      <anchor />
+    </block>
+    <block>
+      three
+      <focus />
+    </block>
+    <block>one</block>
+  </editor>
+)