objectPath.js

// --- Object path operations

export const objGetPathList = ({ path }) => {
  let pathList;
  if (Array.isArray(path)) {
    pathList = path;
  } else if (typeof path === "string") {
    pathList = path.split("/");
  }
  return pathList;
};

export const objTraverseTo = ({ root, pathList, create = false }) => {
  let obj = root;
  for (let i = 0; i < pathList.length - 1; i++) {
    const key = pathList[i];
    let nextObj = obj[key];
    if (!nextObj) {
      if (!create) return;
      obj[key] = nextObj = {};
    }
    obj = nextObj;
  }
  return obj;
};

export const objGetAtPath = ({ root, path }) => {
  const pathList = objGetPathList({ path });
  if (!pathList || !pathList.length) return;
  const obj = objTraverseTo({ root, pathList });
  if (!obj) return;
  return obj[pathList[pathList.length - 1]];
};

export const objSetAtPath = ({ root, path, value }) => {
  const pathList = objGetPathList({ path });
  if (!pathList || !pathList.length) return;
  const obj = objTraverseTo({ root, pathList, create: true });
  if (!obj) return;
  obj[pathList[pathList.length - 1]] = value;
  return root;
};

export const objAddAtPath = ({ root, path, value }) => {
  const pathList = objGetPathList({ path });
  if (!pathList || !pathList.length) return;
  const obj = objTraverseTo({
    root,
    pathList,
    create: true
  });
  const key = pathList[pathList.length - 1];
  const list = obj[key] || [];
  const len = list.push(value);
  obj[key] = list;
  return len - 1;
};