Request type definitions in package.json or DefinitelyTyped

[ajvincent]

import { spy } from "spyfs";

Could not find a declaration file for module 'spyfs'. '/home/ajvincent/filesystem/filterfs/node_modules/spyfs/lib/index.js' implicitly has an 'any' type.
Try npm i --save-dev @types/spyfs if it exists or add a new declaration (.d.ts) file containing declare module 'spyfs';ts(7016)

Obviously I can add the declare line, but it would not have any type definition information for me to use...

https://www.typescriptlang.org/docs/handbook/declaration-files/publishing.html#handbook-content