@engineersamuel/istruthy NPM

Table of Contents

Why

Most truthiness libraries are either extremely basic or simply adhere to the standard defnition of Truthy in JavaScript.

However, what happens when you want to consider '', [], {}, 0, or [null] false? This is where @engineersamuel/istruthy comes in.

Install

$ npm i -D @engineersamuel/istruthy

Usage

import { isTruthy, isFalsy } from '@engineersamuel/istruthy';

console.log(isTruthy('abc')); // prints true
console.log(isTruthy('', { isEmptyStringFalse: true })); // prints false

console.log(isFalse('abc')); // prints false
console.log(isFalsy('', { isEmptyStringFalse: true })); // prints true

See the *.spec.ts files in the ./test directory for a great reference on using isTruthy.

If you want to reference this library directly in html:

<!DOCTYPE html>
<html lang="en">
<head>
    <title>My Page</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- Other resources here -->
    <!-- ... -->
    <!-- Assembler CSS -->
    <script src="https://cdn.jsdelivr.net/npm/@engineersamuel/istruthy@1.0.0/dist/index.min.js"></script>
</head>
<body>
<!-- Your code here -->
  <script>
    console.log(Truthiness.isTruthy('abc')); // prints true
    console.log(Truthiness.isTruthy('', { isEmptyStringFalse: true })); // prints false

    console.log(Truthiness.isFalse('abc')); // prints false
    console.log(Truthiness.isFalsy('', { isEmptyStringFalse: true })); // prints true
  </script>
</body>
</html>

Note that the UMD is built with rollup.js (Which is minimally necessary considering there are no dependencies) and the global variable name is Truthiness hence in the above browser environment you would access isTruthy via Truthiness.isTruthy.

Config

Option	Default	Description
isZeroFalse	false	When set to `true` then `0` will be will be evaluated to false. Ex. `isTruthy(0, { isZeroFalse: true}); // returns false`
isInfinityFalse	false	When set to `true` then `Infinity` and `-Infinity` will be will be evaluated to false. Ex. `isTruthy(Infinity, { isInfinityFalse: true}); // returns false`
isEmptyStringFalse	false	When set to `true` then `''` will be will be evaluated to false. Ex. `isTruthy('', { isEmptyStringFalse: true}); // returns false`
isEmptyObjectFalse	false	When set to `true` then `{}` will be will be evaluated to false. Ex. `isTruthy({}, { isEmptyObjectFalse: true}); // returns false`
isEmptyArrayFalse	false	When set to `true` then `[]` will be will be evaluated to false. Ex. `isTruthy([], { isEmptyArrayFalse: true}); // returns false`
isFilteredArrayFalse	false	When set to `true` then `[null, undefined]` will be will be evaluated to false. Ex. `isTruthy([null, undefined], { isFilteredArrayFalse: true }); // returns false` Note: This specific flag will recursively check each value, so passing options to isTruthy are recursively respected.
isFalsyArrayFalse	false	When set to `true` then `[null, undefined]` will be will be evaluated to false. Ex. `isTruthy([null, undefined], { isFalsyArrayFalse: true})/ // returns false` Ex. `isTruthy([0, ''], { isFalsyArrayFalse: true, isZeroFalse: true, isEmptyStringFalse: true }); // returns false` Note: This specific flag will recursively check each value, so passing options to isTruthy are recursively respected.

Testing

npm run test

  63 passing (38ms)

----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
----------|---------|----------|---------|---------|-------------------
All files |     100 |      100 |     100 |     100 |
 index.ts |     100 |      100 |     100 |     100 |
----------|---------|----------|---------|---------|-------------------