handle-change-text-nodes.ts

/*
 *  This file is part of CoCalc: Copyright © 2020 Sagemath, Inc.
 *  License: MS-RSL – see LICENSE.md for details
 */

import { Operation, Text } from "slate";
import { nextPath, splitTextNodes } from "./split-text-nodes";

// Transform some text nodes into some other text nodes.
export function handleChangeTextNodes(
  nodes: Text[],
  nextNodes: Text[],
  path: number[]
): Operation[] {
  if (nodes.length == 0) throw Error("must have at least one nodes");
  if (nextNodes.length == 0) throw Error("must have at least one nextNodes");

  const operations: Operation[] = [];

  let node = nodes[0];
  if (nodes.length > 1) {
    // join together everything in nodes first
    for (let i = 1; i < nodes.length; i++) {
      operations.push({
        type: "merge_node",
        path: nextPath(path),
        position: 0, // make TS happy; seems ignored in source code
        properties: {}, // make TS happy; seems ignored in source code -- probably a typescript error.
      });
      node = { ...node, ...{ text: node.text + nodes[i].text } }; // update text so splitTextNodes can use this below.
    }
  }

  for (const op of splitTextNodes(node, nextNodes, path)) {
    operations.push(op);
  }

  return operations;
}

export function isAllText(nodes: any[]): nodes is Text[] {
  for (const node of nodes) {
    if (!Text.isText(node)) return false;
  }
  return true;
}