Adding declarations file manually (TypeScript)

Question

I didn't find a declaration file for 'google-spreadsheet' so I'm trying to create one by myself:

in typings -> modules, I've added a new folder named "google-spreadsheet", and there I've added a new file named "index.d.ts" which has the following content:

export class GoogleSpreadsheet {

}

In the client file I have this:

import * as GoogleSpreadsheet from 'google-spreadsheet';

But 'google-spreadsheet' is marked with red, saying:

TS2307 Cannot find module 'google-spreadsheet'.

BTW I've NPM-installed 'google-spreadsheet' and it works JavaScriptly. Only the TypeScript bothers me here.

Any ideas how to solve that?

Answer 1

From the root of your project:

1. mkdir -p src/@types/google-spreadsheet - create a folder for your module's type declarations.
2. echo "declare module 'google-spreadsheet';" > src/@types/google-spreadsheet/index.d.ts

Also, ensure your tsconfig is configured to include the @types folders using the typeRoots option.

{
  "compilerOptions": {
    "typeRoots": ["src/@types", "node_modules/@types"]
  }
}

Also, you might want to take a look at the documentation on declaration files.

Answer 2

If you dont need to care about the typings inside this module you can only create a *.d.ts file and put the following content (e.g. create a typings.d.ts):

declare module 'google-spreadsheet';

To define the types inside the module you can change the above code to:

declare module 'google-spreadsheet' {
    // define the types...
}