Update selection in insertText operation

src/models/selection.js

@@ -569,6 +569,32 @@ class Selection extends new Record(DEFAULTS) {
     })
   }
 
+  /**
+   * Extend the start point forward `n` characters.
+   *
+   * @param {Number} n (optional)
+   * @return {Selection} selection
+   */
+
+  extendStartOffset(n = 1) {
+    return this.isBackward
+      ? this.merge({ focusOffset: this.focusOffset + n })
+      : this.merge({ anchorOffset: this.anchorOffset + n })
+  }
+
+  /**
+   * Extend the end point forward `n` characters.
+   *
+   * @param {Number} n (optional)
+   * @return {Selection} selection
+   */
+
+  extendEndOffset(n = 1) {
+      return this.isBackward
+        ? this.merge({ anchorOffset: this.anchorOffset + n })
+        : this.merge({ focusOffset: this.focusOffset + n })
+  }
+
   /**
    * Extend the focus point to the start of a `node`.
    *

src/transforms/apply-operation.js

@@ -106,11 +106,23 @@ function insertNode(state, operation) {
 
 function insertText(state, operation) {
   const { path, offset, text, marks } = operation
-  let { document } = state
+  let { document, selection } = state
+  const { startKey, endKey, startOffset, endOffset } = selection
   let node = document.assertPath(path)
+
+  // Update the document
   node = node.insertText(offset, text, marks)
   document = document.updateDescendant(node)
-  state = state.merge({ document })
+
+  // Update the selection
+  if (startKey == node.key && startOffset > offset) {
+    selection = selection.extendStartOffset(text.length)
+  }
+  if (endKey == node.key && endOffset > offset) {
+    selection = selection.extendEndOffset(text.length)
+  }
+
+  state = state.merge({ document, selection })
   return state
 }