JSDoc doesnt support generics correctly

🔎 Search Terms

jsdoc generics

🕗 Version & Regression Information

• This is a crash
• This changed between versions ______ and _______
• This changed in commit or PR _______
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________
• I was unable to test this on prior versions because _______

⏯ Playground Link

No response

💻 Code

Given the following code:

function api<T>(endpoint: string): Promise<T> {
  return fetch(endpoint).then(res => res.json());
}

When I consume the api function in a .js file, I'd still like to leverage the T generic via JSDoc-only. There currently isnt a straightforward way to do this, and the DX of this could definitely be improved.

🙁 Actual behavior

Cant leverage the T generic

🙂 Expected behavior

I can leverage the T generic

Additional information about the issue

This is a long overdue feature :)

Reproduce the api example in a .js consumer and investigate how TypeScript currently handles JSDoc generics. No specific source file or test is identified in the issue; done means JavaScript users can express and consume the T generic through JSDoc with improved developer experience.