improved-map

Some trivial convenience methods for Maps.

Installation

npm install improved-map

API

Import/require this library to enhance the Map objects. Nothing is exported.

Map.fromObject(source)

Returns a new Map created from the source object's own enumerable property key, value pairs.

NOTE: Key, value pairs are added to the Map in the order provided by Object.entries, which is implementation dependent.

NOTE: Numeric property keys on an object are actually stored as strings, and will be added to the Map as such, e.g. Map.fromObject({41: 43}) === new Map().set('41', 43).

Map.assign(target, ...sources)

The Map.assign method is used to copy key, value pairs from one or more source Maps to the target Map. It returns the target Map. Values in the target Map will be overwritten by values with the same key in source Maps. Later sources' values will simply overwrite earlier ones.

Map.prototype.update(...sources)

Calls Map.assign with this as the target.

Map.prototype.pop(key[, otherwise])

The pop method returns the value associated with key after deleting the key-value pair from the Map. If key isn't in the Map, it returns otherwise, if provided, or else undefined.

Map.prototype.toObject()

The toObject method returns an object with properties based on the key-value pairs of the Map. Keys of the Map that aren't strings or symbols are converted to strings before being added to the returned object.

Tests

Tests are written using Jest, with TypeScript support provided by ts-jest.