fix: restore handle() return type to Promise<Response>

[eL1fe]

Summary

• Fixes handle used to return a Promise<Response> not it returns Promise<any> #1630
• Restores the handle() method return type from Promise<any> to Promise<Response>
• Also adds explicit return type to the fetch getter

Problem

The handle method was returning Promise<any> instead of Promise<Response> because:

1. composeGeneralHandler creates a function via Function() constructor, which returns any
2. Neither handle nor fetch had explicit return type annotations
3. TypeScript inferred the type as any

Solution

Added explicit return types:

• handle now returns Promise<Response>
• fetch getter now returns (request: Request) => Response | Promise<Response>

Test plan

• Build passes
• Existing tests pass (23 pre-existing failures unrelated to this change)
• Type inference verified with reproduction from handle used to return a Promise<Response> not it returns Promise<any> #1630

Summary by CodeRabbit

• Refactor
  • Enhanced API type signatures with explicit return type annotations to improve type safety and provide clearer contracts for request handling and response processing.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

Walkthrough

This PR restores explicit type annotations to two public method signatures in the Elysia class: the handle method now explicitly returns Promise<Response>, and the fetch getter declares its return type as (request: Request) => Response | Promise<Response>. No functional behavior changes.

Changes

Cohort / File(s)	Change Summary
Type Signature Restoration src/index.ts	handle method explicitly returns Promise<Response> (fixes regression from 1.4.19); fetch getter explicitly typed as (request: Request) => Response | Promise<Response> to enforce type consistency at public API surface

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Poem

🐰 A Promise lost, now found once more,
Type safety restored to our beloved store!
Promise<Response> shines bright and clear,
No more any shadows—type safety here! ✨

Pre-merge checks and finishing touches

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: restoring the handle() method's return type to Promise, which is the primary objective of this PR.
Linked Issues check	✅ Passed	The PR successfully addresses issue #1630 by restoring handle() return type to Promise and adding explicit type annotation to the fetch getter.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to resolving the type inference issue in handle() and fetch getter, with no unrelated modifications present.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

---

📜 Recent review details

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between f751caf and 05af4b8.

📒 Files selected for processing (1)

• src/index.ts

🔇 Additional comments (2)

src/index.ts (2)

8047-8047: LGTM! Explicit return type correctly restores type safety.

The addition of : Promise<Response> to the handle method properly addresses issue #1630. Since handle is async and delegates to this.fetch(request), the Promise wrapper is guaranteed, making Promise<Response> the correct return type.

---

8054-8054: LGTM! Explicit function signature prevents type inference issues.

The explicit return type (request: Request) => Response | Promise<Response> correctly types the fetch getter. This ensures TypeScript doesn't infer any from the dynamically composed handlers created by composeGeneralHandler or createDynamicHandler, directly addressing the root cause described in the PR objectives.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}