[Bug]: Namespace-import barrel emits references to nonexistent *2 members

[chenxin-yan]

Description

Bundling declarations for a barrel that gives explicit typeof annotations to namespace-imported exports produces references to nonexistent *2 namespace members.

For example, the generated declaration contains:

declare const makeModel2: typeof ModelModule.makeModel2;
declare const createSession2: typeof SessionModule.createSession2;

But the generated namespaces only export makeModel and createSession, so consumers fail to type-check.

This reproduces with @bunup/dts@0.14.53, which includes the namespace-import alias restoration fix.

Versions

• Bun: 1.3.13
• Bunup: 0.16.32
• @bunup/dts: 0.14.53
• TypeScript: 7.0.2
• Platform: Linux x64

Minimal reproduction

package.json

{
  "name": "bunup-dts-namespace-repro",
  "private": true,
  "type": "module",
  "devDependencies": {
    "bunup": "0.16.32",
    "typescript": "7.0.2"
  }
}

tsconfig.json

{
  "compilerOptions": {
    "declaration": true,
    "isolatedDeclarations": true,
    "module": "Preserve",
    "moduleResolution": "bundler",
    "target": "ESNext",
    "strict": true
  },
  "include": ["src/**/*.ts"]
}

src/model.ts

export interface Model {
  readonly name: string;
}

export const makeModel = (name: string): Model => ({ name });

src/session.ts

import type { Model } from "./model.js";

export interface Session {
  readonly model: Model;
}

export const createSession = (model: Model): Session => ({ model });

src/index.ts

import * as ModelModule from "./model.js";
import * as SessionModule from "./session.js";

export const makeModel: typeof ModelModule.makeModel = ModelModule.makeModel;
export const createSession: typeof SessionModule.createSession = SessionModule.createSession;

export type { Model } from "./model.js";
export type { Session } from "./session.js";

consumer.ts

import { createSession, makeModel } from "./dist/index.js";

createSession(makeModel("demo"));

Commands

bun install
bunup src/index.ts --target bun
tsc --noEmit --module Preserve --moduleResolution bundler --target ESNext consumer.ts

Actual result

Bunup exits successfully, but the consumer type-check fails:

dist/index.d.ts(15,46): error TS2551: Property 'makeModel2' does not exist on type 'typeof ModelModule'. Did you mean 'makeModel'?
dist/index.d.ts(16,52): error TS2551: Property 'createSession2' does not exist on type 'typeof SessionModule'. Did you mean 'createSession'?

Generated dist/index.d.ts excerpt:

declare namespace ModelModule {
  export { makeModel, Model };
}

declare namespace SessionModule {
  export { createSession, Session };
}

declare const makeModel2: typeof ModelModule.makeModel2;
declare const createSession2: typeof SessionModule.createSession2;
export { makeModel2 as makeModel, createSession2 as createSession, Session, Model };

--dts.splitting produces the same invalid declaration. In the larger project where this was discovered, --dts.infer-types also produces the same invalid references.

Expected result

The generated declaration should reference the namespace's existing makeModel and createSession members, and the consumer should type-check successfully.

Workaround

Disable Bunup declaration bundling and let TypeScript emit modular declarations:

bunup src/index.ts --target bun --no-dts && tsc --emitDeclarationOnly --rootDir src --outDir dist