typescript global type code example
Example: typescript declare global
ts// Type definitions for [~THE LIBRARY NAME~] [~OPTIONAL VERSION NUMBER~]
// Project: [~THE PROJECT NAME~]
// Definitions by: [~YOUR NAME~] <[~A URL FOR YOU~]>
/*~ If this library is callable (e.g. can be invoked as myLib(3)),
*~ include those call signatures here.
*~ Otherwise, delete this section.
*/
declare function myLib(a: string): string;
declare function myLib(a: number): number;
/*~ If you want the name of this library to be a valid type name,
*~ you can do so here.
*~
*~ For example, this allows us to write 'var x: myLib';
*~ Be sure this actually makes sense! If it doesn't, just
*~ delete this declaration and add types inside the namespace below.
*/
interface myLib {
name: string;
length: number;
extras?: string[];
}
/*~ If your library has properties exposed on a global variable,
*~ place them here.
*~ You should also place types (interfaces and type alias) here.
*/
declare namespace myLib {
//~ We can write 'myLib.timeout = 50;'
let timeout: number;
//~ We can access 'myLib.version', but not change it
const version: string;
//~ There's some class we can create via 'let c = new myLib.Cat(42)'
//~ Or reference e.g. 'function f(c: myLib.Cat) { ... }
class Cat {
constructor(n: number);
//~ We can read 'c.age' from a 'Cat' instance
readonly age: number;
//~ We can invoke 'c.purr()' from a 'Cat' instance
purr(): void;
}
//~ We can declare a variable as
//~ 'var s: myLib.CatSettings = { weight: 5, name: "Maru" };'
interface CatSettings {
weight: number;
name: string;
tailLength?: number;
}
//~ We can write 'const v: myLib.VetID = 42;'
//~ or 'const v: myLib.VetID = "bob";'
type VetID = string | number;
//~ We can invoke 'myLib.checkCat(c)' or 'myLib.checkCat(c, v);'
function checkCat(c: Cat, s?: VetID);
}