@geronimus/resolve-type-name

resolveTypeName

Gives the name of the type of a value, whether that type is a primitive, an object literal, or an object returned by a constructor function.

• If the value is a primitive type (eg, boolean, number, string ), then it returns the name of that type.

• If the value is null, then it returns the text null.

• If the value is a function, then it returns the text function.

• If the value was defined as an object literal, then it returns the text object.

• If the value is an object defined with a constructor function (eg, new Date()), then it returns the name of the constructor (eg, "Date").

However, BEWARE!!!

This function is intended primarily to construct meaningful error and log messages during the development phase of a project.

It is not intended for use in program logic, and certainly never to produce any user-facing content.

The reason is that - for objects created using a constructor function - the value returned is the value of Object.prototype.constructor.name. If your code gets minified, then the constructor function's original name will be replaced by a shortened, unrecognizable, and potentially randomized name.

This means that this function:

• Should never be used to determine the type of a user-defined object in program logic. (Use the instanceof operator instead.)
• Will likely be unhelpful for production logging, and should not be used to produce error messages that may become visible to the end user.

Example

const resolveTypeName = require( "@geronimus/resolve-type-name" );

function resolveTypeName( undefined ); \\ => "undefined"
function resolveTypeName( true ); \\ => "boolean"
function resolveTypeName( 1 ); \\ => "number"
function resolveTypeName( "text" ); \\ => "string"
function resolveTypeName( null ); \\ => "null"
function resolveTypeName( () => {} ); \\ => "function"
function resolveTypeName( {} ); \\ => "object"
function resolveTypeName( new Date() ); \\ => "Date"