How to disable default import if declare module has no default export?

[枯萎の花 (Withered-Flower-0422)]

// foo.d.ts
declare module "foo" {
    export const bar: () => void
    // no default export
}

// test.ts
import foo from "foo" // no errors

Before ts6.0, there's an option allowSyntheticDefaultImports, set which to false can solve this problem. But now allowSyntheticDefaultImports=false has been removed.

[Ryan Cavanaugh (RyanCavanaugh)]

There's not really a way to do this since we don't know from declare module "foo" { if it's a CommonJS or ESM module. One way you can fix that ambiguity is to add export const __esModule: boolean to declare module "foo", though.