Global namespaces from script files and module files via declare global considered different

[blutorange]

Search Terms

declaration merging declare global script module

Problem

(Yeah, I know, globals again. I would also like to use modules, but that's hard to impossible for large existing projects. primefaces/primefaces#12717)

When you have a global script file (without import / export) and a module file that both amend a namspace in the global scope, typedoc seems to consider these as different.

When using the plugin typedoc-plugin-merge-modules, that results in the namespaces not getting merged. But I think the issue is not with the plugin, as it seems to happen even without the plugin. For example:

// base.ts
namespace PrimeFaces {
  export interface WindowExtensions{}
}
interface Window extends PrimeFaces.WindowExtensions {}

// src/a.ts
import "./module.js"; // make this a module file
declare global {
  namespace PrimeFaces {
    export interface WindowExtensions{
      a: string;
    }
  }
}

// src/b.ts
// similar a.ts

// src/c.ts
namespace PrimeFaces {
  export interface WindowExtensions{
    c: string;
  }
}

// src/d.ts
// similar to c.ts

// index.ts
console.log(window.a, window.b, window.c, window.d);

Now when generate docs from that, d/PrimeFaces is marked as a re-export of c/PrimeFaces. But a/PrimeFaces and b/PrimeFaces are not and contain only a and b, respectively. Interestingly enough though, c/PrimeFaces contains all of a, b, c and d.

With typedoc-plugin-merge-modules, that then results in duplicates:

Repro

git clone https://github.com/blutorange/primefaces-js-refactor-test.git
cd primefaces-js-refactor-test/
git checkout demo-typedoc-merge-script-module
yarn install
yarn tsc # note that this compiles, so all interfaces point to the same thing
yarn typedoc  --out docs src/index.ts src/a.ts src/b.ts src/c.ts src/d.ts src/module.ts
open docs/index.html

[blutorange]

Just to let you know, I Just checked out your commit, seems to be working nicely in our case. 👍

Before there were multiple namespaces

Now they're replaced with nice references: