Writing your own *.d.ts file

When you are writing your own *.d.ts file, the stakes are very high. Let's create our own *.d.ts file for any module. Say we want to write a module for my-custom-library:

1. Create one blank file called my-custom-library.d.ts and write the following inside it:

declare module my-library

This will silence the compiler and won't throw any errors.

1. Next, you need to define all the methods there and what the return type expected out of each method is. You can find several templates here: http://www.typescriptlang.org/docs/handbook/declaration-files/templates.html. Here, we need to define the available methods and what they are returning. For example, take a look at the following code snippet:

declare function myFunction1(a: string): string; 
declare function myFunction2(a: number): number;