.verb.md

January 31, 2018 · View on GitHub

Usage

const has = require('{%= name %}');

Create an isEmpty function by returning the inverse of the result from has-values:

const isEmpty = val => !has(val);

Supported types

Arrays

console.log(has(['a']));      //=> true
console.log(has([0]));        //=> true
console.log(has([[[]]]));     //=> false
console.log(has([[], []]));   //=> false
console.log(has([]));         //=> false

Booleans

console.log(has(true));  //=> true
console.log(has(false)); //=> true

Buffers

console.log(has(new Buffer()));      //=> false
console.log(has(new Buffer('foo'))); //=> true

Dates

Dates are always true.

console.log(has(new Date())); //=> true

Errors

Returns false if err.message is an empty string.

console.log(has(new Error()));      //=> false
console.log(has(new Error('foo'))); //=> true

Functions

Functions are always true.

console.log(has(function(foo) {})); //=> true
console.log(has(function() {}));    //=> true

Maps

console.log(has(new Map()));                 //=> false
console.log(has(new Map([['foo', 'bar']]))); //=> true

Null

null is always true, as it's assumed that this is a user-defined value, versus undefined which is not.

console.log(has(null)); //=> true

Objects

console.log(has({})); //=> false
console.log(has({ a: 'a' }}));        //=> true
console.log(has({ foo: undefined })); //=> false
console.log(has({ foo: null }));      //=> true

Numbers

console.log(has(1)); //=> true
console.log(has(0)); //=> true

Regular expressions

console.log(has(new RegExp()));      //=> false
console.log(has(new RegExp('foo'))); //=> true

Sets

console.log(has(new Set()));               //=> false
console.log(has(new Set(['foo', 'bar']))); //=> true

Strings

console.log(has('a')); //=> true
console.log(has(''));  //=> false

Undefined

console.log(has());          //=> false
console.log(has(void 0));    //=> false
console.log(has(undefined)); //=> false