@atlaskit/editor-plugin-show-diff/dist/es2019/pm-plugins/decorations/utils/getMarkChangeRanges.js

ShowDiff plugin for @atlaskit/editor-core

import { AddMarkStep, RemoveMarkStep } from '@atlaskit/editor-prosemirror/transform';
const extractMarkStep = step => {
  if (step instanceof AddMarkStep) {
    return {
      type: 'add',
      from: step.from,
      to: step.to,
      markName: step.mark.type.name
    };
  }
  if (step instanceof RemoveMarkStep) {
    return {
      type: 'remove',
      from: step.from,
      to: step.to,
      markName: step.mark.type.name
    };
  }
  return undefined;
};
export const getMarkChangeRanges = steps => {
  const resultRanges = [];
  let lastOp;
  for (const step of steps) {
    const op = extractMarkStep(step);
    if (!op) {
      continue;
    }

    // Check if previous operation cancels this one
    if (lastOp && lastOp.from === op.from && lastOp.to === op.to && lastOp.markName === op.markName && lastOp.type !== op.type) {
      resultRanges.pop();
    } else {
      resultRanges.push({
        fromB: op.from,
        toB: op.to
      });
    }
    lastOp = op;
  }
  return resultRanges;
};