TS1038
A 'declare' modifier cannot be used in an already ambient context.
When defining the shape of a module in a declaration file, all definitions within the declared module are already ambient, so they do not need the declare attribute:
declare module "some-npm-module" {
export declare const a: number;
}Fix: Remove declare keyword.
Remove the unnecessary declare keyword:
declare module "some-npm-module" {
export const a: number;
}