I18next: Make the translation function fully type-safe

[karol-majewski]

🚀 Feature Proposal

With the latest advancements in TypeScript, it's now possible to infer the correct paths from an object type. TypeScript 4.1 introduces recursive conditional types, and there is a PR open that will enable string type concatenation on the type level.

Motivation

18next.t accepts arbitrary strings. This allows silly human errors, since it's easy to make a typo.

Example

I put together a TypeScript Playground illustrating the improved definition.

Once https://github.com/microsoft/TypeScript/pull/40336 is merged and released, the improved definition can be put in a separate file loaded only for the ones using the minimum required TypeScript version. In package.json, it should say:

{
    "typesVersions": {
        ">=4.1.0-0": {
            "*": [
                /* Path to the new definition */
            ]
        }
    }
}

[rosskevin]

Very nice! Once the new TS is released, we can accept a PR for this. We may need to think about modifying our usage tests so that we can properly test it, we currently do not have any expect error notations being used.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[raynor85]

This should be reopened, it is a must have feature and we already have a solution for it.

[jamuhl]

stalebot

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[akosbalogh]

up!?