Simple Guards

Description

Simple utilities to add guard clauses to yout JS code.

Guards raises an Error if a given condition is truthy.

Features

• Guards not executed in production environment (process.env.NODE_ENV !== "production")
• Guards can be checked lazily

Install

npm instal simple-guards

Usage

To set a simple guard:

import { guard } from "simple-guards";

function division(numerator, denominator) {
  guard(denominator === 0, "denominator cannot be zero");

  // more awful code
}

You can also pass a function to lazy evaluate an expensive guard:

function division(numerator, denominator) {
  guard(() => expensiveDetectionOfZero(denominator), "denominator cannot be zero");

  // more awful code
}

If you want to lazy evaluate many guards you can use the guards method to avoid excessive wrapper functions:

import { guards } from "simple-guards";

function division(numerator, denominator) {
  guards((guard) => {
    guard(expensiveDetectionOfZero(numerator), "we don't want numerator to be zero");
    guard(expensiveDetectionOfZero(denominator), "denominator cannot be zero");
  })

  // more awful code
}