CocoRoboDesktop/pdf1.js/node_modules/fast-safe-stringify/index.js

module.exports = stringify
stringify.default = stringify
stringify.stable = deterministicStringify
stringify.stableStringify = deterministicStringify

var arr = []

// Regular stringify
function stringify (obj, replacer, spacer) {
  decirc(obj, '', [], undefined)
  var res = JSON.stringify(obj, replacer, spacer)
  while (arr.length !== 0) {
    var part = arr.pop()
    part[0][part[1]] = part[2]
  }
  return res
}
function decirc (val, k, stack, parent) {
  var i
  if (typeof val === 'object' && val !== null) {
    for (i = 0; i < stack.length; i++) {
      if (stack[i] === val) {
        parent[k] = '[Circular]'
        arr.push([parent, k, val])
        return
      }
    }
    stack.push(val)
    // Optimize for Arrays. Big arrays could kill the performance otherwise!
    if (Array.isArray(val)) {
      for (i = 0; i < val.length; i++) {
        decirc(val[i], i, stack, val)
      }
    } else {
      var keys = Object.keys(val)
      for (i = 0; i < keys.length; i++) {
        var key = keys[i]
        decirc(val[key], key, stack, val)
      }
    }
    stack.pop()
  }
}

// Stable-stringify
function compareFunction (a, b) {
  if (a < b) {
    return -1
  }
  if (a > b) {
    return 1
  }
  return 0
}

function deterministicStringify (obj, replacer, spacer) {
  var tmp = deterministicDecirc(obj, '', [], undefined) || obj
  var res = JSON.stringify(tmp, replacer, spacer)
  while (arr.length !== 0) {
    var part = arr.pop()
    part[0][part[1]] = part[2]
  }
  return res
}

function deterministicDecirc (val, k, stack, parent) {
  var i
  if (typeof val === 'object' && val !== null) {
    for (i = 0; i < stack.length; i++) {
      if (stack[i] === val) {
        parent[k] = '[Circular]'
        arr.push([parent, k, val])
        return
      }
    }
    if (typeof val.toJSON === 'function') {
      return
    }
    stack.push(val)
    // Optimize for Arrays. Big arrays could kill the performance otherwise!
    if (Array.isArray(val)) {
      for (i = 0; i < val.length; i++) {
        deterministicDecirc(val[i], i, stack, val)
      }
    } else {
      // Create a temporary object in the required way
      var tmp = {}
      var keys = Object.keys(val).sort(compareFunction)
      for (i = 0; i < keys.length; i++) {
        var key = keys[i]
        deterministicDecirc(val[key], key, stack, val)
        tmp[key] = val[key]
      }
      if (parent !== undefined) {
        arr.push([parent, k, val])
        parent[k] = tmp
      } else {
        return tmp
      }
    }
    stack.pop()
  }
}