doff

doff

A powerful tool to free your objects and arrays from unwanted content

Instalation

npm install --save doff

Features

• wipe, i.e. remove, unwanted content
• blur, i.e. mask, sensitive content
• mutate or accumulate a target
• choose start or end depth
• symbol keys support
• no external dependencies

Instances

Alongside the default instance

const doff = require('doff');

you can also create a new instance with custom options

// Options for a new instance are result of merge between provided and default options
const instance = doff.create({
  mutate: true,
  symbols: true
});

if needed, you can overwrite options of the default instance

// Only provided keys are overwritten
doff.use({
  symbols: true,
  falltrough: true,
  blur: {
    paths: 'top.secret.path'
  }
});

Notice

Overwriting options of the default instance won't affect instances created before, but it will affect instances created later on, if options are not isolated.

Usage

Working with instance options

const target = {
  some: 'value',
  state: false,
  big: 0,
  nest: {
    nothing: null
  },
  sequence: [17, 'is', '', undefined, {}],
  unique: new Set(),
  pattern: /[how]_[does]_[this]_[work]/
};

const output = doff(target);

console.log(target === output);
// => false
console.log(output);
/* =>
{
  some: 'value',
  state: false,
  big: 0,
  sequence: [17, 'is'],
  pattern: /[how]_[does]_[this]_[work]/
}
 */

Working with custom options

const target = [
  'bold statement',
  NaN,
  true,
  {
    now: {
      lets: {
        nest: {
          things: undefined
        }
      }
    }
  },
  null,
  new Set(),
  ['', {}, [null]]
];

doff(target, {
  mutate: true,
  depth: 2
});

console.log(target);
/* =>
[
  'bold statement',
  true,
  {
    now: {
      lets: {
        nest: {
          things: undefined
        }
      }
    }
  },
  [[null]]
]
 */

Working with isolated options

const target = {
  start: undefined,
  with: true,
  empty: {},
  or: '',
  simple: {
    [Symbol('key')]: 17
  },
  pattern: /[0-9]/
};

// Using a instance with isolated options
const instance = doff.create({
  isolate: true
});
let output = instance(target);

// Is equivalent of providing isolated options
output = doff(target, {
  isolate: true
});

console.log(target === output);
// => false
console.log(target.empty === output.empty);
// => true
console.log(target.simple === output.simple);
// => true
console.log(output);
/* =>
{
  start: undefined,
  with: true,
  empty: {},
  or: '',
  simple: {
    [Symbol('key')]: 17
  },
  pattern: /[1-9]/
}
 */

and not providing wipe and blur keys, will output an accumulator which is a clone of a target. However, not all values will be cloned, just ones with a type object that have enumerable keys, symbol keys are dependent on a symbols option.
Providing isolated options to the doff.use is the same as providing non-isolated options.

Options

The list of available options for doffing

• isolate - determines how provided options are used, when true options are used as is, otherwise merged with options of the default instance
• mutate - determines what to do with a provided target, when true a target is mutated, otherwise a new one, with a same prototype, is constructed
• depth - defines how deep to go, accepts
  • number 0 - go all the way
  • number > 0 - go up to the defined depth
  • number < 0 - start from the defined depth
• symbols - determines which keys are taken into consideration, when true symbol keys are also taken into consideration, otherwise they are ignored
• fallthrough - determines what to do with kept entries, when true they will reach the wipe, otherwise they won't
• preserve - takes precedence over the reference and the wipe
  • arrays - determines what to do with arrays, when true array values will stay intact, otherwise they will be inspected
  • objects - determines what to do with objects, when true object values will stay intact, otherwise they will be inspected
  • paths - defines paths to keep, accepts
    • string - a single path to keep, e.g. some.important[0].path
    • Array.<string> - a list of paths to keep, e.g. [some.important[0].path, this.one.also]
  • types - defines types to keep, accepts
    • string - a single type to keep, e.g. [object Map]
    • function - a single type to keep, e.g. Set, evaluated using instanceof
    • Array.<string|function> - a combination of previous two
• reference - an object to take as the reference, i.e. if an object has a path keep it, otherwise inspect, takes precedence over the wipe
• wipe - values to wipe from a target, accepts
  • string falsy.relaxed - falsy values excluding, false and 0
  • string falsy.strict - falsy values
  • string empty.loose - falsy values, excluding 0 and false, objects without own keys, arrays and likes with length of 0, maps and sets with size of 0
  • string empty.relaxed, alias false - falsy values, excluding 0 and false, objects without own string enumerable keys, arrays and likes with length of 0, maps and sets with size of 0
  • string empty.strict, alias true - falsy values, objects without own string enumerable keys, arrays and likes with length of 0, maps and sets with size of 0
  • Array - of values
  • function - with the signature (value, path, target), returning true for wiping or false otherwise
• blur - paths that are not wiped can be blurred, e.g. masked. Suitable for a sensitive data, e.g. passwords
  • paths - to blur, i.e. replace with a mask value, accepts
    • string - a single path to blur using value of the mask key
    • object - where key is a path to blur and value is a mask to use
    • Array.<string|object> - a combination of previous two
    • function - with the signature (value, path, target), returning a mask to use
  • mask - the default mask to use for blurring

Defaults

Default values of available options, i.e. options of the default instance

{
  isolate: false,
  mutate: false,
  depth: 0,
  symbols: false,
  fallthrough: false,
  preserve: {
    arrays: false,
    objects: false,
    paths: undefined,
    types: ['[object Date]', '[object RegExp]']
  },
  reference: undefined,
  wipe: false,
  blur: {
    paths: undefined,
    mask: '*******'
  }
}

Callback

As mentioned above callback provided as wipe and / or blur.paths options should look like

/**
 * @param {Object} value - the value to inspect
 * @param {Object} path - the path of the value inside the target
 * @param {Object} target - the provided target
 */
function (value, path, target) {
  // Hm, what to do now?
}

Path

Parameter path passed to a callback is an object containing asString and asArray properties. Take for a example the following target,

  const target = {
    start: [{
      [Symbol('of')]: 'something'
    }]
  };

path passed to a callback in a case of the 'something' value, would look like

{
  asString: 'start[0].@@of'
  asArray: ['start', 0, Symbol('of')]
}

API

doff(target[, options])

Doff unwanted entries and return the result.

doff.use(options)

Available only on the default instance!
Overwrite options of the default instance with provided ones and return the default instance.

doff.create(options)

Available only on the default instance!
Create a new instance using provided options.

doff.getOptions()

Return options of a target instance.

doff.aim(target[, options])

Alias for the doff.

License

This project is licensed under the terms of the MIT license.