dcsm-type-helper

A vanilla JavaScript library for checking the type of variables in a more robust and accurate way than the typeof operator.

Features

• Provides a simple and easy-to-use interface for checking the types of values in JavaScript.

• Allows you to check the type of a single value or multiple values at once.

• Provides options for customizing the behavior of the TypeOf class.

• Provides a set of methods for checking the type of values such as isNumber, isObject, isBigInt, etc.

• It also comes with some other useful methods such as isEmptyArray, isBooleanTrue, isNumberZero, etc.

Table of Contents

• Installation
• Usage
  • Using the default export
  • Get help information
  • Using the class directly
  • Handling errors
  • Using the class with options
  • Get the type names of values
• API Reference
  • TypeOf
    • constructor
    • setOptions
    • getOptions
    • isTypeOf
    • notTypeOf
    • isTypeOfValues
    • notTypeOfValues
    • getTypeOf
  • typeOfShorthand
  • getTypeOf
  • getTypeOfPretty
  • typeOf
  • typeOfSilent
  • typeOfHelp
• License

Installation

To install dcsm-type-helper, you can use npm:

npm install dcsm-type-helper

Usage

Using the default export

// See the output of the typeOfHelp method for a list of all the supported types and helper methods.
import typeOfShorthand from "dcsm-type-helper";
const {
  isString
} = typeOfShorthand;
console.log(isString("hello")); // true

Get help information

import { typeOfHelp } from "dcsm-type-helper";
typeOfHelp();

The typeOfHelp function provides help information on the supported types and helper methods. It will console.log the following string to the console:

Using the class directly

import { TypeOf } from "dcsm-type-helper";

const typeOfInstance = new TypeOf("hello", 42, true);
console.log(typeOfInstance.isString); // false
console.log(typeOfInstance.someValueIsString); // true
console.log(typeOfInstance.someValueNotNumber); // true

const types = typeOfInstance.getTypeOf();
console.log(types); // ["string", "number", "boolean"]

Handling errors

A simple try-catch example for handling the error thrown when using the notTypeOf method:

import { TypeOf } from "dcsm-type-helper";
// Create a new instance of the TypeHelper class. Take note that no values are provided to the constructor.
const tryTypeOf = new TypeOf();
try {
  // This will throw an error because there are no values to check provided to the constructor.
  tryTypeOf.notTypeOf('object');
} catch (error) {
  console.error(error.name); // InvalidValuesToCheckError
  console.error(error.message); // No values to check were provided!
}

Using the class with options

import { TypeOf } from "dcsm-type-helper";
const optionsTypeOf = new TypeOf("hello", 42, true);

optionsTypeOf.setOptions = {
  enableCapitalizedTypeNames: true,
  disableThrowErrors: true,
};
console.log(optionsTypeOf.getTypeOf());

Get the type names of values

The getTypeOf function allows you to get the type of a single value or multiple values at once.

import { getTypeOf } from "dcsm-type-helper";
const myString = "hello";
const myNumber = 42;
const myBoolean = true;

const stringType = getTypeOf(myString);
console.log(stringType); // "string"

const types = getTypeOf(myString, myNumber, myBoolean);
console.log(types); // ["string", "number", "boolean"]

API Reference

TypeOf [class]

constructor(...values: any[]): TypeOf

Creates a new instance of the TypeOf class with the specified values and options.

• values: The values to check the type of.

Throws an error if no values are provided to the constructor. With error name InvalidValuesToCheckError and message No values to check were provided!.

TypeOf - setOptions [setter]

setOptions(options: TypeOfOptions): void

Sets the options for an instance of the TypeOf class.

TypeOfOptions = {
  enableCapitalizedTypeNames?: boolean;
  disableThrowErrors?: boolean;
}

options: An optional object with the following properties:

• enableCapitalizedTypeNames: A boolean value indicating whether to use capitalized type names. If true, the TypeOf class will return capitalized type names (e.g. String instead of string). If false (the default), the TypeOf class will use lowercase type names.
• disableThrowErrors: A boolean value indicating whether to disable throwing errors. If

If enableCapitalizedTypeNames is set to true, the getTypeOf method will return capitalized type names (e.g. String instead of string). If enableCapitalizedTypeNames is set to false (the default), the getTypeOf method will return lowercase type names.

If disableThrowErrors is set to true true, the TypeOf class will not throw errors and instead return undefined. It is important to remember that by returning undefined instead of throwing errors, the TypeOf class will not provide any information on why the error occurred. If disableThrowErrors is set to false (the default), the TypeOf class will throw errors with information on why the error occurred.

Throws error if options is not an object. With error name InvalidOptionsTypeError and message Options must be an object!.... Throws error if options.enableCapitalizedTypeNames is not a boolean. With error name InvalidOptionsError and message The options provided are not valid!.... Throws error if options.disableThrowErrors is not a boolean. With error name InvalidOptionsError and message The options provided are not valid!.... Throws error if options.enableCapitalizedTypeNames is not a boolean. With error name InvalidOptionsError and message The options provided are not valid!.... Throws error if options.disableThrowErrors is not a boolean. With error name InvalidOptionsError and message The options provided are not valid!....

Example:

import { TypeOf } from "dcsm-type-helper";
const typeOfInstance = new TypeOf("hello", 42, true);
const options = { enableCapitalizedTypeNames: true, disableThrowErrors: true };
typeOfInstance.setOptions = options;

TypeOf - getOptions [getter]

getOptions(): TypeOfOptions

Gets the options for an instance of the TypeOf class.

• Returns an object with the properties enableCapitalizedTypeNames and disableThrowErrors.

TypeOf - isTypeOf [method]

isTypeOf(type: string, options?: TypeOfOptions): boolean | undefined

Checks if all values are of the specified type.

• type: The type to check the values against.
• Returns true if all values are of the specified type, or false if not. If disableThrowErrors is set to true, it will return undefined instead of throwing an error.

TypeOf - notTypeOf [method]

notTypeOf(type: string, options?: TypeOfOptions): boolean | undefined

Checks if all values are not of the specified type.

• type: The type to check the values against.
• Returns true if all values are not of the specified type, or false if not. If disableThrowErrors is set to true, it will return undefined instead of throwing an error.
• This method is the opposite of the isTypeOf method.

TypeOf - isTypeOfValues [method]

isTypeOfValues(type: string, options?: TypeOfOptions): boolean[] | undefined

Checks if all values are of the specified type. Returns an array of booleans.

• type: The type to check the values against.
• Returns an array of booleans with the same length as the number of values passed to the constructor. Each boolean indicates whether the corresponding value is of the specified type or not. If disableThrowErrors is set to true, it will return undefined instead of throwing an error.
• This method is the same as the isTypeOf method, except that it returns an array of booleans instead of a single boolean.
• This method is useful if you want to check the type of multiple values at once.
• Example:

import { TypeOf } from "dcsm-type-helper";
const typeOfInstance = new TypeOf("hello", 42, true);
const types = typeOfInstance.isTypeOfValues("string");
console.log(types); // [true, false, false]

TypeOf - notTypeOfValues [method]

notTypeOfValues(type: string, options?: TypeOfOptions): boolean[] | undefined

Checks if all values are not of the specified type. Returns an array of booleans.

• type: The type to check the values against.
• Returns an array of booleans with the same length as the number of values passed to the constructor. Each boolean indicates whether the corresponding value is not of the specified type or not. If disableThrowErrors is set to true, it will return undefined instead of throwing an error.
• This method is the same as the notTypeOf method, except that it returns an array of booleans instead of a single boolean.
• This method is useful if you want to check the type of multiple values at once.
• Example:

import { TypeOf } from "dcsm-type-helper";
const typeOfInstance = new TypeOf("hello", 42, true);
const types = typeOfInstance.notTypeOfValues("string");
console.log(types); // [false, true, true]

TypeOf - getTypeOf [method]

getTypeOf(options?: TypeOfOptions): string | string[] | undefined

Gets the type of the values as a string or an array of strings.

• Returns a string with the type of the value if a single value is passed, or an array of strings with the types of the values if multiple values are passed.
• Example:

import { TypeOf } from "dcsm-type-helper";
const typeOfInstance = new TypeOf("hello", 42, true);
const options = { enableCapitalizedTypeNames: true, disableThrowErrors: true };
// since the you can pass options directly to the getTypeOf method, you can also do this instead of setting the options on the instance of the TypeOf class. 
const types = typeOfInstance.getTypeOf(options);
console.log(types); // ["String", "Number", "Boolean"]

typeOfShorthand [object] (default export)

[method]: (...values: any[]) => boolean | boolean[]

An object with shorthand methods for checking the type of values. Each method is named after the type it checks prefixed with the use case.

See the output of the typeOfHelp method for a list of all the supported types and helper methods.

For example, the isString method checks if a value is a string.

getTypeOf [function]

getTypeOf(...values: any[]): string | string[]

Checks the type of a single value or multiple values at once.

• values: The values to check the type of.

getTypeOfPretty [function]

getTypeOfPretty(...values: any[]): string | string[]

Checks the type of a single value or multiple values at once and returns a pretty string.

• values: The values to check the type of.
• same as getTypeOf but returns a pretty string

typeOf [function]

typeOf(...values: any[]): TypeOf

Creates a new instance of the TypeOf class with the specified values and options.

• values: The values to check the type of.

typeOfSilent [function]

typeOfSilent(...values: any[]): TypeOf

Creates a new instance of the TypeOf class with the specified values and options.

• values: The values to check the type of.
• same as typeOf but does not throw errors

typeOfHelp [function]

typeOfHelp(): void

Console logs the following string with help information:

The name of each type and helper method is a combination of a 'use case' name and a 'type/helper' name.
For instance, the method 'isString' which checks if one or all values are a string is a combination of the 'use case' name 'is' and the 'type/helper' name 'String'.

The 'use case' names are:
is            // checks if all values are of the specified 'type/helper'
not           // checks if all values are not of the specified 'type/helper'
everyValueIs  // same as the 'is' 'use case'
everyValueNot // same as the 'not' 'use case'
someValueIs   // checks if at least one value is of the specified 'type/helper'
someValueNot  // checks if at least one value is not of the specified 'type/helper'

The 'type/helper' names are:
Arguments
Array
Arraybuffer
Arrayiterator
Asyncfunction
Asyncgenerator
Asyncgeneratorfunction
Bigint
Bigint64array
Biguint64array
Boolean
Dataview
Date
Error
Float32array
Float64array
Function
Generator
Generatorfunction
Infinity
Int16array
Int32array
Int8array
Internal
Map
Mapiterator
Module
Modulenamespaceobject
Nan
Null
Number
Object
Promise
Proxy
Regexp
Set
Setiterator
String
Stringiterator
Symbol
Typedarray
Uint16array
Uint32array
Uint8array
Uint8clampedarray
Undefined
Weakmap
Weakset
EmptyArray
EmptyObject
EmptyString
Empty
BooleanTrue
BooleanFalse
NumberZero
NumberPositive
NumberNegative
NumberMaxSafeInteger

License

This project is licensed under the Mozilla Public License 2.0 - see the LICENSE file for details.