Package Exports

typechecker

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (typechecker) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

TypeChecker

Utilities to get and check variable types (isString, isPlainObject, isRegExp, etc)

Install

Backend

Install Node.js
npm install --save typechecker

Frontend

See Browserify

Usage

Example

require('typechecker').isRegExp(/^a/)  // returns true

Methods

getObjectType - returns the object string of the value, e.g. when passed /^a/ it'll return "[object RegExp]"
getType - returns lower case string of the type, e.g. when passed /^a/ it'll return "regex"
isPlainObject - returns true if the value doesn't have a custom prototype
isError - returns true if the value an error, otherwise false
isDate - returns true if the value is a date, otherwise false
isArguments - returns true if the value is function arguments, otherwise false
isFunction - returns true if the value is a function, otherwise false
isRegExp - returns true if the value is a regular expression instance, otherwise false
isArray - returns true if the value is an array, otherwise false
isNumber - returns true if the value is a number ("2" is a string), otherwise false
isString - returns true if the value is a string, otherwise false
isBoolean - returns true if the value is a boolean, otherwise false
isNull - returns true if the value is null, otherwise false
isUndefined - returns true if the value is undefined, otherwise false
isEmpty - returns true if the value is null or undefined
isEmptyObject - returns true if the object has no keys that are its own

Notes

Why should I use this instead of say instanceof? Under certain circumstances instanceof may not return the correct results. This occurs with node's vm module especially, and circumstances where an object's prototype has been dereferenced from the original. As such, for basic == and === checks (like a === null), you're fine not using this, but for checks when you would have done instanceof (like err instanceof Error), you should try to use this instead. Plus things like isEmptyObject and isPlainObject are darn useful!

History

You can discover the history inside the History.md file

typechecker