push-and-pop

Scoping the easy way.

Installation

$ npm install push-and-pop

Usage

const {scope: settings, push, pop} = require("./index.js")({
  angleMode: "radians"
});

const cosine = (n) => {
  switch (settings.angleMode) {
    case "degrees": return Math.cos(n * Math.PI / 180);
    case "radians": return Math.cos(n);
    default: throw Error("settings.angleMode must be degrees or radians");
  }
};

const {deepStrictEqual: equal} = require("assert");

cosine(Math.PI * 2); // 1

// Change the settings...
push({angleMode: "degrees"});
cosine(360); // 1

// ...And change them back.
pop();

API

require("push-and-pop")(properties = {})

Create an object p containing scope, push, and pop The scope is a null object, so it doesn't have methods like toString.

p.scope

An object with properties from a call to require("push-and-pop").

p.push(properties = {})

Add properties to a scope that can be popped off later.

p.pop(times = 1)

Pop a layer off the scope zero or more times.