@atlaskit/editor-plugin-list/dist/es2019/pm-plugins/actions/join-list-items-scenarios/join-list-item-with-paragraph.js

List plugin for @atlaskit/editor-core

import { insertContentDeleteRange, isListNode } from '@atlaskit/editor-common/utils';
import { Fragment } from '@atlaskit/editor-prosemirror/model';
// Case for when a users selection is at the end of a paragraph, the paragraph
// is followed by a list, and they delete forward
export const joinListItemWithParagraph = ({
  tr,
  $next,
  $head
}) => {
  // For empty paragraphs before a list
  if ($head.parent.content.size < 1) {
    insertContentDeleteRange(tr, tr => tr.doc.resolve($head.pos), [], [[$head.pos - 1, $head.pos]]);
    return true;
  }
  const paragraphPosition = $head.pos;
  const list = tr.doc.nodeAt($next.pos - 1);
  const firstListItem = tr.doc.nodeAt($next.pos);
  if (!list || !firstListItem) {
    return false;
  }
  const firstChildNodeOfFirstListItem = firstListItem.firstChild;
  if (!firstChildNodeOfFirstListItem) {
    return false;
  }
  const lastChildOfFirstListItem = firstListItem.lastChild;
  const firstGrandchildOfFirstListItem = firstChildNodeOfFirstListItem.firstChild;
  const firstListItemHasOneChildWithNoNestedLists = hasSingleChild(firstListItem) && firstChildNodeOfFirstListItem.childCount < 2 && $next.nodeAfter;
  const firstListItemContainsParagraphAndNestedList = !hasSingleChild(firstListItem) && lastChildOfFirstListItem && isListNode(lastChildOfFirstListItem);
  const insertions = [];
  const deletions = [];

  // For lists that only have one list item with no children - need to remove remaining list
  if (hasSingleChild(list) && hasSingleChild(firstListItem) && $next.nodeAfter) {
    deletions.push([tr.mapping.map($next.pos - 1), tr.mapping.map($next.pos + $next.nodeAfter.nodeSize + 1)]);
  }

  // For first list items that have a paragraph and a list
  if (firstListItemContainsParagraphAndNestedList) {
    // Ignored via go/ees005
    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
    const firstListItemNestedList = Fragment.from(lastChildOfFirstListItem.content);
    insertions.push([firstListItemNestedList, tr.mapping.map($next.pos)]);
  }

  // For first list item has one child & no nested lists OR first list items that have a paragraph and a list
  if (firstListItemHasOneChildWithNoNestedLists || firstListItemContainsParagraphAndNestedList) {
    deletions.push([tr.mapping.map($next.pos), tr.mapping.map($next.pos + firstListItem.nodeSize - 1)]);
    const firstListItemText = Fragment.from(firstChildNodeOfFirstListItem.content);
    insertions.push([firstListItemText, paragraphPosition]);
    insertContentDeleteRange(tr, tr => tr.doc.resolve($head.pos), insertions, deletions);
    return true;
  }

  // For any first list items that have multiple children (eg. multiple paragraphs)
  if (firstListItem.childCount > 1) {
    insertions.push([Fragment.from(firstChildNodeOfFirstListItem.content), paragraphPosition]);
    deletions.push([tr.mapping.map($next.pos + 1), tr.mapping.map($next.pos + firstChildNodeOfFirstListItem.nodeSize + 1)]);
    insertContentDeleteRange(tr, tr => tr.doc.resolve($head.pos), insertions, deletions);
    return true;
  }

  // For any remaining first list items that have a single child (eg. single paragraph, multiple lines of text)
  if (firstGrandchildOfFirstListItem && firstGrandchildOfFirstListItem.type.name === 'hardBreak') {
    const nodeSizeOfGrandchild = firstGrandchildOfFirstListItem ? firstGrandchildOfFirstListItem.nodeSize : 0;
    deletions.push([tr.mapping.map($next.pos + 2), tr.mapping.map($next.pos + 2 + nodeSizeOfGrandchild)]);
  } else {
    insertions.push([Fragment.from(firstChildNodeOfFirstListItem.content), paragraphPosition]);
    const nodeSizeOfFirstChild = firstChildNodeOfFirstListItem.nodeSize;
    deletions.push([tr.mapping.map($next.pos), tr.mapping.map($next.pos + 2 + nodeSizeOfFirstChild)]);
  }
  insertContentDeleteRange(tr, tr => tr.doc.resolve($head.pos), insertions, deletions);
  return true;
};
const hasSingleChild = node => {
  return node.childCount === 1;
};