is-a

legible type checking "micro library"

Installation

$ npm install is-a

Usage

var is = require('is-a');

var StringOrRegExp = [is.STRING, is.REGEXP];

var thing1 = /mischief/;

console.log(is(thing1).a.String); //false
console.log(is(thing1).not.a.Number); //true
console.log(is(thing1).an.Array); //false
console.log(is(thing1).a.RegExp); //true
console.log(is(thing1).a(StringOrRegExp)); //true
console.log(is(thing1).a.Primitive); //false
console.log(is(thing1).a.CoreObject); //true
console.log(is(thing1).not.a.JsonBasicType); //true
console.log(is(thing1).a.BuiltinType); //true


var thing2 = "mayhem";

console.log(is(thing2).a.String); //true
console.log(is(thing2).not.a.Number); //true
console.log(is(thing2).an.Array); //false
console.log(is(thing2).a.RegExp); //false
console.log(is(thing2).a(StringOrRegExp)); //true
console.log(is(thing2).a.Primitive); //true
console.log(is(thing2).a.CoreObject); //true
console.log(is(thing2).not.a.JsonBasicType); //false
console.log(is(thing2).a.BuiltinType); //true


var myType = is.ARRAY;

console.log(myType.is.a.String); //false
console.log(myType.is.not.a.Number); //true
console.log(myType.is.an.Array); //true
console.log(myType.is.a.RegExp); //false
console.log(myType.is.a(StringOrRegExp)); //false
console.log(myType.is.a.Primitive); //false
console.log(myType.is.a.CoreObject); //true
console.log(myType.is.not.a.JsonBasicType); //false
console.log(myType.is.a.BuiltinType); //true

Tests

this is the complete list of tests. .a, .an, and .is are optional, is(x).not... is the same as !is(x)...

Testing: is X a Type

• is(x).Arguments
• is(x).an.Array
• is(x).a.Boolean
• is(x).a.Date
• is(x).a.Function
• is(x).a.Math
• is(x).Null
• is(x).a.Number
• is(x).an.Object
• is(x).a.RegExp
• is(x).a.String
• is(x).Undefined

Testing: is X not a Type

• is(x).not.Arguments
• is(x).not.an.Array
• is(x).not.a.Boolean
• is(x).not.a.Date
• is(x).not.a.Function
• is(x).not.a.Math
• is(x).not.Null
• is(x).not.a.Number
• is(x).not.an.Object
• is(x).not.a.RegExp
• is(x).not.a.String
• is(x).not.Undefined

Testing: is X a GeneralType

general types are

• BuiltinType: one of (Arguments, Array, Boolean, Date, Function, Math, Null, Number, Object, RegExp, String, Undefined)
• JsonBasicType: one of (Array, Boolean, Null, Number, Object, String, Undefined)
• CoreObject: one of (Array, Boolean, Date, Function, Math, Number, RegExp, String)
• Primitive: one of (Boolean, Null, Number, String, Undefined)

general types can be tested for just like simple types

• is(x).a.BuiltinType
• is(x).a.JsonBasicType
• is(x).a.CoreObject
• is(x).a.Primitive
• is(x).a([is.STRING, is.ARRAY])

.not still works

• is(x).not.a.BuiltinType
• is(x).not.a.JsonBasicType
• is(x).not.a.CoreObject
• is(x).not.a.Primitive
• is(x).not.a([is.STRING, is.ARRAY])

builtin types can be tested too

• is.ARRAY.a.JsonBasicType
• is.REGEXP.a([is.STRING, is.ARRAY])

everything else

var is = require('is-a');

var thing1 = /mischief/;

console.log(is(thing1).toString()); // "RegExp"
console.log(is(thing1).toType()); // "[object RegExp]"