jsonpointer.js

/*
  This file is copied from https://github.com/janl/node-jsonpointer
  because I was not able to use it directly from the jsonpointer package.
*/

var hasExcape = /~/;
var escapeMatcher = /~[01]/g;
function escapeReplacer(m) {
  switch (m) {
    case "~1":
      return "/";
    case "~0":
      return "~";
  }
  throw new Error("Invalid tilde escape: " + m);
}

function untilde(str) {
  if (!hasExcape.test(str)) return str;
  return str.replace(escapeMatcher, escapeReplacer);
}

function setter(obj, pointer, value) {
  var part;
  var hasNextPart;

  for (var p = 1, len = pointer.length; p < len; ) {
    part = untilde(pointer[p++]);
    hasNextPart = len > p;

    if (typeof obj[part] === "undefined") {
      // support setting of /-
      if (Array.isArray(obj) && part === "-") {
        part = obj.length;
      }

      // support nested objects/array when setting values
      if (hasNextPart) {
        if ((pointer[p] !== "" && pointer[p] < Infinity) || pointer[p] === "-")
          obj[part] = [];
        else obj[part] = {};
      }
    }

    if (!hasNextPart) break;
    obj = obj[part];
  }

  var oldValue = obj[part];
  if (value === undefined) delete obj[part];
  else obj[part] = value;
  return oldValue;
}

function compilePointer(pointer) {
  if (typeof pointer === "string") {
    pointer = pointer.split("/");
    if (pointer[0] === "") return pointer;
    throw new Error("Invalid JSON pointer.");
  } else if (Array.isArray(pointer)) {
    return pointer;
  }

  throw new Error("Invalid JSON pointer.");
}

function get(obj, pointer) {
  if (typeof obj !== "object") throw new Error("Invalid input object.");
  pointer = compilePointer(pointer);
  var len = pointer.length;
  if (len === 1) return obj;

  for (var p = 1; p < len; ) {
    obj = obj[untilde(pointer[p++])];
    if (len === p) return obj;
    if (typeof obj !== "object") return undefined;
  }
}

function set(obj, pointer, value) {
  if (typeof obj !== "object") throw new Error("Invalid input object.");
  pointer = compilePointer(pointer);
  if (pointer.length === 0) throw new Error("Invalid JSON pointer for set.");
  return setter(obj, pointer, value);
}

function compile(pointer) {
  var compiled = compilePointer(pointer);
  return {
    get: function (object) {
      return get(object, compiled);
    },
    set: function (object, value) {
      return set(object, compiled, value);
    }
  };
}

if (typeof window === "undefined" || navigator.userAgent.includes("jsdom")) {
  module.exports = {
    get,
    set,
    compile
  };
}