Extending an interface from a third party definition file

Question

I'm using this definition file in my Typescript code. The problem is that, according to Sequelize documentation to set the length of a string column, I should define its type as:

 Sequelize.STRING(20)

and the current definition file doesn't allow this. It allows only Sequelize.STRING (which makes a default column length of 255).

I want to create my own definition file, patching (extending) this interface so that it supports both situations, or at least setting Sequelize.STRING as any so that I don't get compiler errors.

Any idea how should I do it?

Answer 1

Fix at :

    interface DataTypeString extends DataTypeStringBase {
        (length?:number): any; // ADD this 
    }

A PR + TEST would be appreciated :)

Update

Would it be possible somehow to implement this in my own .d.ts file, extending the provided one?

FAILED ATTEMPT Untested but probably correct:

declare module "sequelize"
{
  module sequelize {
     interface DataTypeString {
            (length?:number): any;
     }
  }
} 

Update 2

Based on how the definition is currently written you can't extend it externally https://github.com/Microsoft/TypeScript/issues/2784