fix: add "types" field to conditional exports

[TomAFrench]

I'm experiencing a lot of issues when trying to resolve the types

src/fft/single_fft.ts:1:26 - error TS7016: Could not find a declaration file for module 'threads'. '/home/tom/Programming/turbo-prover-js/node_modules/threads/index.mjs' implicitly has an 'any' type.
  There are types at '/home/tom/Programming/turbo-prover-js/node_modules/threads/dist/index.d.ts', but this result could not be resolved when respecting package.json "exports". The 'threads' library may need to update its package.json or typings.

1 import { Transfer } from 'threads';
                           ~~~~~~~~~

src/pippenger/single_pippenger.ts:3:26 - error TS7016: Could not find a declaration file for module 'threads'. '/home/tom/Programming/turbo-prover-js/node_modules/threads/index.mjs' implicitly has an 'any' type.
  There are types at '/home/tom/Programming/turbo-prover-js/node_modules/threads/dist/index.d.ts', but this result could not be resolved when respecting package.json "exports". The 'threads' library may need to update its package.json or typings.

3 import { Transfer } from 'threads';
                           ~~~~~~~~~

src/wasm/worker.ts:2:37 - error TS7016: Could not find a declaration file for module 'threads/observable'. '/home/tom/Programming/turbo-prover-js/node_modules/threads/observable.mjs' implicitly has an 'any' type.
  Try `npm i --save-dev @types/threads` if it exists or add a new declaration (.d.ts) file containing `declare module 'threads/observable';`

2 import { Subject, Observable } from 'threads/observable';
                                      ~~~~~~~~~~~~~~~~~~~~

src/wasm/worker.ts:3:34 - error TS7016: Could not find a declaration file for module 'threads/worker'. '/home/tom/Programming/turbo-prover-js/node_modules/threads/worker.mjs' implicitly has an 'any' type.
  Try `npm i --save-dev @types/threads` if it exists or add a new declaration (.d.ts) file containing `declare module 'threads/worker';`

3 import { expose, Transfer } from 'threads/worker';
                                   ~~~~~~~~~~~~~~~~

src/wasm/worker_factory.ts:2:39 - error TS7016: Could not find a declaration file for module 'threads'. '/home/tom/Programming/turbo-prover-js/node_modules/threads/index.mjs' implicitly has an 'any' type.
  There are types at '/home/tom/Programming/turbo-prover-js/node_modules/threads/dist/index.d.ts', but this result could not be resolved when respecting package.json "exports". The 'threads' library may need to update its package.json or typings.

2 import { spawn, Thread, Worker } from 'threads';

The last error explicitly calls out that changes need to be made to the threads.js package.json. I've then added a "types" field for each of the conditional exports.

[TomAFrench]

Related to #462

[tien]

default needs to come last else it will throw an error

[Altrue]

Since it's been more than a month now, someone had to do it to stop the PR from stagnating :)

[CMCDragonkai]

Yea the types in this package doesn't work. In my vscode it says:

Could not find a declaration file for module 'threads'. '/home/cmcdragonkai/Projects/js-workers/node_modules/threads/index.mjs' implicitly has an 'any' type.
  There are types at '/home/cmcdragonkai/Projects/js-workers/node_modules/threads/dist/index.d.ts', but this result could not be resolved when respecting package.json "exports". The 'threads' library may need to update its package.json or typings.ts(7016)

This with native ESM support.

When I was using CJS, I could directly import the type files, hacking around the dist. But with ESM, I think you need to specify the types key properly above require, and default... etc.

[CMCDragonkai]

These are the types I care about:

import type { ModuleThread } from 'threads';
import type { ModuleMethods } from 'threads/dist/types/master';
import type { QueuedTask } from 'threads/dist/master/pool-types';

They used to work when I was using CJS. Now I'm transitioning to ESM, and the last 2 imports no longer work.

[TomAFrench]

@Altrue @tien Ah, thank you. I must admit I didn't test that as a required ordering to fields in JSON doesn't really make sense.

I can't quite remember why I was running into this issue anymore (most likely a side project I'm not particularly active in Ah, this was for work but we've gone down a different path) so this isn't a huge priority to me anymore and @andywer doesn't seem to be actively merging PRs currently.

[CMCDragonkai]

@andywer are you still working on this? Without this PR I think ESM downstream projects can't use this.

And I actually care about these types: #470 (comment)