assert-types.js

A small JavaScript library for arguments assertion. Browser and Node.JS compatible.

• What's the mission
• Dependencies
• How to install
• How to use
  • Loading library
  • Assertions
  • Conditions
• License

What's the mission

The main mission is to provide simple and slick API for checking arguments and throwing exceptions. Let's get rid of explicit complex conditions.

Dependencies

• Underscore.js

7.5 Kb unminified with comments, 3.6 Kb minified

How to install

NPM

npm install assert-types

Development and contributing

Install dependencies

npm install && bower install

Build Project

npm run build

Run Tests

npm run test

How to use

Loading library

If you're running in Node.js, you can require assertTypes.js like so:

var assertTypes = require('assert-types');

It also supports Require.js:

require.config({
	paths: {
		'assert-types': 'assert-types.js/dist/assert-types.min.js'
	}
});

require(['assert-types'], function(assert) {});

Also assertTypes.js could be included with an HTML <script> tag and assertTypes variable will be visible globally.

Assertions

// Numbers

assertTypes.number(num);
assertTypes.numberPositive(num);
assertTypes.numberNegative(num);
assertTypes.numberOdd(num);
assertTypes.numberEven(num);
assertTypes.numberInt(num);
assertTypes.numberFloat(num);
assertTypes.numberRange(num, min, max);

// Equals

assertTypes.equal(value, expectedValue);

// Boolean

assertTypes.bool(value);
assertTypes.boolTrue(value);
assertTypes.boolFalse(value);

// String

assertTypes.string(value);
assertTypes.stringNotEmpty(value);

// Other 

assertTypes.object(value);
assertTypes.fn(value);
assertTypes.array(value);
assertTypes.instance(value, instance);
assertTypes.nulled(value); 
assertTypes.defined(value);
assertTypes.date(value);

In case if assertion is failed, assertTypes will throw Error.

Conditions

Also the library has possibility to define conditions. Let's take a look here:

// These could be translated as: if value is defined then it should be a number
assertTypes.number(value, assertTypes.conditionIfDefined);

// Other examples
assertTypes.object(value, assertTypes.conditionIfDefined);

// You can define your own conditions
assertTypes.defined(value, today === 'Friday'); 

// Condition could be a function
assertTypes.numberPositive(value, function(value) {
    
    return today === 'Friday' || today === 'Monday';
    
});

The assertion will be performed if condition is true;

Maintainers

• Alexander Suevalov

License

MIT