esModuleInterop flag required to build TypeScript project referencing v5.11.0

[ejizba]

Bug Description

Starting in v5.11.0, it seems like the "esModuleInterop" flag is required to get a TypeScript build passing for a project referencing undici. It worked just fine in 5.10.0, and I believe the change to the types files occurred in the following PR by @arontsang, but I'm not sure if it was intentional: #1338

Reproducible By

1. Clone this simple app: https://github.com/ejizba/undicibug
2. Run npm install
3. Run npm build

Expected Behavior

The build passes

Actual Behavior

The build fails with these errors:

node_modules/undici/types/client.d.ts:5:8 - error TS1259: Module '"/undiciBug/node_modules/undici/types/connector"' can only be default-imported using the 'esModuleInterop' flag

5 import buildConnector, {connector} from "./connector";
         ~~~~~~~~~~~~~~

  node_modules/undici/types/connector.d.ts:4:1
    4 export = buildConnector
      ~~~~~~~~~~~~~~~~~~~~~~~
    This module is declared with 'export =', and can only be used with a default import when using the 'esModuleInterop' flag.

node_modules/undici/types/dispatcher.d.ts:6:13 - error TS1259: Module '"/undiciBug/node_modules/undici/types/readable"' can only be default-imported using the 'esModuleInterop' flag

6 import type BodyReadable from './readable'
              ~~~~~~~~~~~~

  node_modules/undici/types/readable.d.ts:4:1
    4 export = BodyReadable
      ~~~~~~~~~~~~~~~~~~~~~
    This module is declared with 'export =', and can only be used with a default import when using the 'esModuleInterop' flag.

node_modules/undici/types/handlers.d.ts:1:8 - error TS1259: Module '"/undiciBug/node_modules/undici/types/dispatcher"' can only be default-imported using the 'esModuleInterop' flag

1 import Dispatcher from "./dispatcher";
         ~~~~~~~~~~

  node_modules/undici/types/dispatcher.d.ts:12:1
    12 export = Dispatcher;
       ~~~~~~~~~~~~~~~~~~~~
    This module is declared with 'export =', and can only be used with a default import when using the 'esModuleInterop' flag.

Environment

Mac
Node 18

Additional context

I can work around the bug by setting esModuleInterop to true in the sample app linked above, but unfortunately that flag causes other problems in my "real" app 😮‍💨

[mcollina]

@kibertoad could you take a look?

[kibertoad]

Sure!

[kibertoad]

Sorry for the delay, will finally have time to look at it on this weekend.