Add new types to package exports definition for ESM support

[ghost]

Description

As of today, it's not possible to resolve the new typings with a TS project using ESM. With these changes, you can import types in ESM project, e.g.:

import type { SearchHit, SearchResponse } from '@opensearch-project/opensearch/api/types'

This is also backwards compatible with projects converting from TS + CommonJS to TS + ESM.

Issues Resolved

Closes #204

Check List

• [ ] New functionality includes testing.
  • [ ] All tests pass
• [x] Linter check was successfull - yarn run lint doesn't show any errors
• [x] Commits are signed per the DCO using --signoff
• [x] Changelog was updated.

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[kavilla]

@AMoo-Miki

[dblock]

Is there a way to add a test for this so we don't break it in the future?

[ghost]

Is there a way to add a test for this so we don't break it in the future?

Unfortunately I'm not sure if there is an easy way to test it - it probably requires setting up a child project with ESM and type checking.

However, after having another look at the type definitions, I noticed the ./api/types -module is already exported from the root typings as opensearchtypes namespace export, similarly as ./api/requestParams. Should we export just the ./api/new as explicit ESM (type) export, and request users to import the types from ./api/types via the root package namespace export? Such as:

import { ApiResponse, opensearchtypes } from '@opensearch-project/opensearch'
import { Client } from '@opensearch-project/opensearch/api/new'

const client: Client
const response: ApiResponse<opensearchtypes.SearchResponse<TDocument>> = await client.search({ ... })

Technically we could export the new types via the root typings as well, but if they're still partially work in progress and opt-in, I'd keep them separate.

[ghost]

@dblock @kavilla @AMoo-Miki not trying to rush anything, but happy to improve upon your request.

I'd suggest we change this PR to export only the new types

    "./api/new": {
      "types": "./api/new.d.ts"
    }

What do you think?

[nhtruong]

@perttukarna Is this related to https://github.com/opensearch-project/opensearch-js/issues/670#issuecomment-1864866676 ?

[ghost]

@nhtruong yes and no. 😄 This won't solve the problem of having two different type definitions for the client, but merely makes the new type definitions available for certain project setups (TS + ESM in particular).

[ghost]

@dblock @kavilla @AMoo-Miki can you take a look, please?

[dblock]

Leaving to @nhtruong to decide and merge.