checkif.js
v0.4.3
Published
Javascript check library
Readme
checkif.js
This library aims to perform various checks in the javascript environment.
Installation
checkif.js is distributed as a npm package.
npm install checkif.jsDocumentation
The library is constituted of a set of checkers to perform different verifications.
is
import { is } from 'checkif.js';Types
This group of methods allows to verify if a given value is from a specific type.
null(value)
Checks if a given value is null.
undefined(value)
Alias und(value)
Checks if a given value is undefined.
nullable(value)
Checks if a given value is null or undefined.
nan(value)
Checks if a given value is NaN. Same as Number.isNaN.
is.nan(NaN); // true
is.nan(Number.NaN); // truearray(value)
Alias arr(value)
Checks if a given value is an array. This method is the same as Array.isArray, if available.
is.array([]); // true
is.array(new Array(0)); // trueboolean(value)
Alias bool(value)
Checks if a given value is a boolean.
is.boolean(true); // true
is.boolean(new Boolean(0)); // truestring(value)
Alias str(value)
Checks if a given value is a string.
is.string(''); // true
is.string(String('')); // true
is.string(new String('')); // truechar(value)
Checks if a given value is a char.
is.char(' '); // true
is.char('1'); // true
is.char(1); // falsedate(value)
Checks if a given value is a date.
is.date(new Date('November 23, 1998 03:24:00')); // true, my birthdate btw ;)number(value)
Alias num(value)
Checks if a given value is a number.
is.number(Number(1)); // true
is.number(new Number(1)); // true
is.number(1); // trueregexp(value)
Alias reg(value)
Checks if a given value is a regular expression.
is.regexp(\a\); // true
is.regexp(RegExp()); // true
is.regexp(new RegExp()); // trueobject(value)
Alias obj(value)
Checks if a given value is an object.
is.object({}); // true
is.object(String(1)); // true
is.object('1'); // falsepureObject(value)
Alias pure(value)
Checks if a given value is a pure JSON object.
is.pureObject({}); // true
is.pureObject({ value: 1 }); // true
is.pureObject(new Date()); // falsefunction(value)
Alias func(value)
Checks if a given value is a function.
is.function(function () { }); // true
is.function(x => x); // true
is.function(new Function('x', 'return x')); // trueerror(value)
Alias err(value)
Checks if a given value is an error.
is.error(Error('Fatal error')); // true
is.error(new Error('Nothing works anymore')); // truedomNode(value)
Alias dom(value)
Checks if a given value is a DOM node.
// Browser
is.domNode(window.document.body); // true
// Node.js
let dom = new JSDOM(`<html !DOCTYPE><body></body></html>`);
is.domNode(dom.window.document.body); // truewindowObject(value)
Alias window(value)
Checks if a given value is a window object.
// Browser
is.windowObject(window); // true
// Node.js
let dom = new JSDOM(`<html !DOCTYPE></html>`)
is.windowObject(dom.window); // trueRegExp
This group of methods allows to verify if a given string is from a specific known type of value.
To be implemented
String
This group of methods allows to verify if a given string is a from a specific format.
lowerCase(value)
Check if a given string is lower case.
is.lowerCase('abc'); // true
is.lowerCase('abc 123'); // true
is.lowerCase('ABC'); // falseupperCase(value)
Check if a given string is upper case.
is.upperCase('ABC'); // true
is.upperCase('ABC 123'); // true
is.upperCase('abc'); // falseArithemetic
This group of methods allows to verify if a given number is a from a specific class of numbers.
even(value)
Checks if a given value is even.
is.even(10); // true
is.even(11); // falseodd(value)
Checks if a given value is odd.
is.odd(9); // true
is.odd(10); // falseinteger(value)
Alias int(value)
Checks if a given value is an integer.
is.integer(12); // true
is.integer(10.0); // true
is.integer(3.14); // false
is.integer(Number.MIN_VALUE); // false
is.integer(Infinity); // false
is.integer('6');// falseEnvironment
This group of methods allows to verify if the current environment is a specific environment.
To be implemented
Time
This group of methods allows to verify if a date is a specific kind.
past(value)
Checks if a given value is a Date object in the past.
is.past(new Date(0)); // true
let pastDate = new Date();
pastDate.setUTCFullYear(pastDate.getUTCFullYear() - 1);
is.past(pastDate); // true
let futureDate = new Date();
futureDate.setUTCFullYear(futureDate.getUTCFullYear() + 1);
is.past(futureDate); // falsefuture(value)
Checks if a given value is a Date object in the future.
let futureDate = new Date();
futureDate.setUTCFullYear(futureDate.getUTCFullYear() + 1);
is.future(futureDate); // true
is.future(new Date(0)); // false
let pastDate = new Date();
pastDate.setUTCFullYear(pastDate.getUTCFullYear() - 1);
is.future(pastDate); // falsetoday(value)
Checks if a given value is a Date object set today.
let date = new Date();
date.setUTCHours(12);
date.setUTCMinutes(30);
is.today(date); // true
is.today(new Date()); // true
is.today(new Date(0)); // false
let pastDate = new Date();
pastDate.setUTCFullYear(pastDate.getUTCFullYear() - 1);
is.today(pastDate); // false
let futureDate = new Date();
futureDate.setUTCFullYear(futureDate.getUTCFullYear() + 1);
is.today(futureDate); // falseall
all(enumerable, matcher, strict = false)
import { all } from 'checkif.js';This method verifies if all elements in a given enumerable (array or object) match a specific value or function.
all on arrays
all([0, 0, 0, 0], 0); // true
all([2, 4, 6, 8], x => x%2 === 0); // true
all([0, 1, 2, 3], 1); // falseall on objects
all({ x: 1, y: 1 }, 1); // true
let a = {};
all({ x: a, y: a }, x => x === a); // true
all({ x: 0, y: new Number(0) }, function(x){ return x === 0; }); // falseStrict mode
The second parameter of all is automatically resolved as a matcher function when it's a function. But you may want to check if the values are exactly equal to the function (as a value). In this case, you should use the strict mode by setting the 3rd parameter to true (default false).
import { all } from 'checkif.js';
let _function = function (x) { ... };
all({ x: _function, y: _function }, _function, true); // trueFeel free to build complex logic for your checks.
import { all, is } from 'checkif.js';
all({ x: ['a', 'b'], y: ['a', 'c'] }, x => all(x, is.char)); // trueany
any(enumerable, matcher, strict = false)
This method verifies if any element in a given enumerable (array or object) matches a specific value or function.
import { any } from 'checkif.js';
any([0,1,2,3], 2); // true
any([0,1,2,3], x => x === 0); // true
any({ x : 1, y : 0}, x => x === 1); // true
any([0, 1, 2, 3], 1); // false
any({ x : 1, y : 1}, 2); // false
any([0,1,2,3], x => x === 5); //falseany also supports strict mode.
has
This group of methods allows to verify if a given enumerable (array or object) has an element verifying a specific condition. This checker contains the same methods as is. In fact, has.method(array) is equivalent to any(array, is.method).
import { any } from 'checkif.js';
has.uppercase(['abc', 'Abc', 'ABC']); // true
has.even({ x : 1, y : 2, z : 3}); // true
has.function({ x : function(){}}); // true
has.nan([0, 1, 2, 3]); // false
has.integer([1.2, 1.3]); // false
has.null([]); // falsehasOnly
This group of methods allows to verify if a given enumerable (array or object) has only elements verifying a specific condition. This checker contains the same methods as is.
hasOnly.method(array) is equivalent to all(array, is.method).
import { any } from 'checkif.js';
hasOnly.lowercase(['abc', 'def', 'ghi']); // true
hasOnly.integer({ x : 1, y : 2, z : 3}); // true
hasOnly.function({ x : function(){}, y : x => x}); // true
hasOnly.null([null, 1, 2, 3]); // false
hasOnly.odd([1, 2, 3]); // falseatLeast
atLeast(enumerable, count, matcher, strict = false)
Alias atl(enumerable, count, matcher, strict = false)
This method verifies if at least a number of elements in a given enumerable (array or object) match a specific value or function.
import { atLeast } from 'checkif.js';
atLeast([1,1,2,3], 2, 1); // true
atLeast([0,0,2,0], 3, x => x === 0); // true
atLeast({ x : 1, y : 0}, 1, x => x === 1); // true
atLeast([0, 1, 2, 3], 2, 1); // false
atLeast({ x : 1, y : 1}, 3, 2); // false
atLeast([0,1,2,3], 1, x => x === 5); //falseatLeast also supports strict mode.
atMost
atMost(enumerable, count, matcher, strict = false)
Alias atm(enumerable, count, matcher, strict = false)
This method verifies if at most a number of elements in a given enumerable (array or object) match a specific value or function.
import { atMost } from 'checkif.js';
atMost([0, 0, 1, 2], 2, 0); // true
atMost([true, true, true, false], 3, x => x === true); // true
atMost({ x: a, y: a }, 3, x => x === a); // true
atMost([0, 0, 1, 1], 1, 0); // false
atMost({ x: 1, y: 0 }, 0, 1); // false
let _function = function () { return true };
atMost({ x: _function, y: _function }, 1, _function); // falseatMost also supports strict mode.
Contributing
Any help is wanted and welcome. You can check out our github issues and projects or our slack page.
Please follow our contributing guidelines.