Relative reference in generated .d.ts file in a monorepo

[wgcrouch]

When generating a .d.ts file, typescript is including a relative reference for an import, which is imported as a module.

import { a } from "@ts-bug/a";

export function b(text: string) {
  return a(text);
}

generated a definition file:

/// <reference path="../../a/index.d.ts" />
export declare function b(text: string): import("@ts-bug/a").AText;

In this case it is in a mono-repo which may be confusing things, but the reference should be the same as the import.

TypeScript Version:
3.0.3, but also happens with 3.1.0-dev.20180901

Search Terms:
relative reference paths
generated reference relative

Code
I have created a repo with a simple reproduction here https://github.com/wgcrouch/ts-bug

Expected behavior:
The reference /// <reference types="@ts-bug/a" />

Actual behavior:
The reference generated is /// <reference path="../../a/index.d.ts" />

Related Issues:
#26439

[RyanCavanaugh]

Probably a duplicate of the linked related issue

[sebinsua]

@RyanCavanaugh Yes - but this one has a reproduction repository so it should be easier for somebody to get to the root cause on.

[andypillip]

In my case the generated .d.ts file contains syntax errors – is that related to this issue?

/// <reference path="../../../../../../../../node_modules/@types/moduleE/dist/index.d.ts" />

declare const myFunc: () => O<'moduleE'.E<any>>;

The above is invalid, hence definitely a bug.

The file causing this error is as follows:

declare module 'moduleE' {
    export interface E<T> {
…

If I remove the declare module, it's at least generating an @import() around the module name.

And if I replace the arrow function by a regular function, everything works:
export function myFunc(): MyResult<any> {

[weswigham]

@andypillip if you could open up a new issue with a repro, that's be great, it's definitely not (directly) related to the issue in the OP here.