map-object-facade

map-object-facade

Use map as object (e.g. map.a instead of map.get('a'))

Features

• Get and set values using the object dot notation.
• Supports Object calls like Object.keys(map) and delete map[key].
• Supports readonly (sealed) mode and noAdditions (frozen) mode.
• Provides a single function for maps (mapAsObject).
• Transparent: existing Map functionality is not changed.

Usage examples

import mapAsObject from 'map-object-facade'

let map = mapAsObject(new Map());
map.a = 1;
map['b'] = 2;
map.set('c', 3);

map.a === map.get('a');
map.size === 3
Object.keys(map) === map.keys() === ['a', 'b', 'c']

delete map.b
map.size === 2
map.b === map.get('b') === undefined
Object.keys(map) === map.keys() === ['a', 'c']

let readMap = mapAsObject(map, {readonly:true});

Readonly or noAdditions

Object.seal and Object.freeze cannot be set independently on a proxy (which is used in the implementation of objectFacade). Instead, options can be given in the mapAsObject(..) call.

Current supported options are:

• noAdditions (alias: seal) that allows changing values, but no new keys (default: false)
• readonly (alias: freeze) that allows no changes whatsoever (default: false)
• throwOnIgnoredSet will throw if set is ignored due to noAdditions / readonly (default: false -- meaning sets will be silently ignored if not allowed).

For example:

mapAsObject(map, {noAdditions:true, throwOnIgnoredSet:true})

'seal' and 'freeze' are used as alias because they are known names (though not very descriptive).

Changelog

Install

$ npm install map-object-facade

License

MIT (C) Nicolas de Jong