add keepOnSplit option to splitListItem

packages/core/src/commands/splitListItem.ts

@@ -1,13 +1,123 @@
-import { splitListItem as originalSplitListItem } from 'prosemirror-schema-list'
+import {
-import { NodeType } from 'prosemirror-model'
+  NodeType,
+  Node as ProseMirrorNode,
+  Fragment,
+  Slice,
+} from 'prosemirror-model'
+import { canSplit } from 'prosemirror-transform'
 import { Command } from '../types'
 import getNodeType from '../helpers/getNodeType'
 
 /**
  * Splits one list item into two list items.
  */
-export const splitListItem = (typeOrName: string | NodeType): Command => ({ state, dispatch }) => {
+export const splitListItem = (typeOrName: string | NodeType): Command => ({ state, dispatch, editor }) => {
   const type = getNodeType(typeOrName, state.schema)
+  const { $from, $to } = state.selection
 
-  return originalSplitListItem(type)(state, dispatch)
+  // @ts-ignore
+  // eslint-disable-next-line
+  const node: ProseMirrorNode = state.selection.node
+
+  if ((node && node.isBlock) || $from.depth < 2 || !$from.sameParent($to)) {
+    return false
+  }
+
+  const grandParent = $from.node(-1)
+
+  if (grandParent.type !== type) {
+    return false
+  }
+
+  if ($from.parent.content.size === 0 && $from.node(-1).childCount === $from.indexAfter(-1)) {
+    // In an empty block. If this is a nested list, the wrapping
+    // list item should be split. Otherwise, bail out and let next
+    // command handle lifting.
+    if (
+      $from.depth === 2
+      || $from.node(-3).type !== type
+      || $from.index(-2) !== $from.node(-2).childCount - 1
+    ) {
+      return false
+    }
+
+    if (dispatch) {
+      let wrap = Fragment.empty
+      const keepItem = $from.index(-1) > 0
+
+      // Build a fragment containing empty versions of the structure
+      // from the outer list item to the parent node of the cursor
+      for (let d = $from.depth - (keepItem ? 1 : 2); d >= $from.depth - 3; d -= 1) {
+        wrap = Fragment.from($from.node(d).copy(wrap))
+      }
+
+      // Add a second list item with an empty default start node
+      // @ts-ignore
+      wrap = wrap.append(Fragment.from(type.createAndFill()))
+
+      const tr = state.tr.replace(
+        $from.before(keepItem ? undefined : -1),
+        $from.after(-3),
+        new Slice(wrap, keepItem ? 3 : 2, 2),
+      )
+
+      tr
+        // @ts-ignore
+        .setSelection(state.selection.constructor.near(tr.doc.resolve($from.pos + (keepItem ? 3 : 2))))
+        .scrollIntoView()
+    }
+
+    return true
+  }
+
+  const nextType = $to.pos === $from.end()
+    ? grandParent.contentMatchAt(0).defaultType
+    : null
+
+  const extensionAttributes = editor.extensionManager.attributes
+  const currentTypeAttributes = grandParent.attrs
+  const currentNextTypeAttributes = $from.node().attrs
+  const newTypeAttributes = Object.fromEntries(Object
+    .entries(currentTypeAttributes)
+    .filter(([name]) => {
+      const extensionAttribute = extensionAttributes.find(item => {
+        return item.type === grandParent.type.name && item.name === name
+      })
+
+      if (!extensionAttribute) {
+        return false
+      }
+
+      return extensionAttribute.attribute.keepOnSplit
+    }))
+  const newNextTypeAttributes = Object.fromEntries(Object
+    .entries(currentNextTypeAttributes)
+    .filter(([name]) => {
+      const extensionAttribute = extensionAttributes.find(item => {
+        return item.type === $from.node().type.name && item.name === name
+      })
+
+      if (!extensionAttribute) {
+        return false
+      }
+
+      return extensionAttribute.attribute.keepOnSplit
+    }))
+
+  const tr = state.tr.delete($from.pos, $to.pos)
+  const types = nextType
+    ? [{ type, attrs: newTypeAttributes }, { type: nextType, attrs: newNextTypeAttributes }]
+    : [{ type, attrs: newTypeAttributes }]
+
+  // @ts-ignore
+  if (!canSplit(tr.doc, $from.pos, 2, nextType && [null])) {
+    return false
+  }
+
+  if (dispatch) {
+    // @ts-ignore
+    tr.split($from.pos, 2, types).scrollIntoView()
+  }
+
+  return true
 }

packages/extension-task-item/src/task-item.ts

@@ -34,6 +34,7 @@ export const TaskItem = Node.create({
         renderHTML: attributes => ({
           'data-checked': attributes.checked,
         }),
+        keepOnSplit: false,
       },
     }
   },