[Feature] Export RouteInput type

[thadeucity]

Export RouteInput type to fix a bug in elysia/eden

Today Elysia/eden is unable to infer the route input type, this pull request aims to fix this issue by exporting its input types.

import { Elysia } from "elysia";
import { z } from 'zod'

const app = new Elysia()
  .post(
    "/sum", 
    ({body}) => `Sum of ${body.foo} + 2 = ${body.foo + 2}`, 
    { 
      body: z.object({ foo: z.string().transform((numericVal) => parseInt(numericVal)) })
    }
  ).listen(3000);

type Input = typeof app['~RoutesInput']['sum']['post']['body']
/*
{
    foo: string;
}
*/


type Output = typeof app['~Routes']['sum']['post']['body']
/*
{
    foo: number;
}
*/

Summary by CodeRabbit

• New Features

  • Expanded public type surface with richer route-input and schema input/output typings for higher-fidelity type inference across routes, bodies, headers, query, params and responses.
  • Route-building signatures now expose the enhanced input typing for more accurate developer tooling and autocompletion.

• Tests

  • Added comprehensive type-level tests validating inference for transformed and nested schemas.

• Notes

  • Purely type-level changes — no runtime behavior changes.

[coderabbitai]

Walkthrough

Type-level routing infrastructure expanded: new utilities UnwrapRouteInput, InferRouteInput, StripRouteInput added; Elysia class gains a generic RoutesInput and public member ~RoutesInput; comprehensive TypeBox schema unwrapping/transform metadata utilities introduced. Changes are type-level only.

Changes

Cohort / File(s)	Summary
Core Elysia Public API src/index.ts	Adds generic parameter RoutesInput to Elysia, introduces public member ~RoutesInput, changes ~Routes to StripRouteInput<Routes>, and updates route-building method signatures to propagate UnwrapRouteInput and related input types.
Type System / Schema Utilities src/types.ts	Introduces TypeBox wrapper handling and transform metadata (UnwrapWrappers, TransformMetadata, TypeBoxTransformInput, IsOptionalSchema, TypeBoxStaticEncode), adds schema resolution utilities (UnwrapSchema*, UnwrapBodySchema*, UnwrapRoute*), route-input machinery (routeInputSymbol, StripRouteInput, InferRouteInput, InferElysiaRoutesInput), and updates merge/create types to propagate RoutesInput.
Type Tests test/types/routes-input.ts	Adds comprehensive TypeScript tests verifying route input inference and unwrapping across body, query, headers, params, and responses using transformed/coerced schemas and nested structures; purely type-level tests.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Poem

🐇 I nibble types and hop in delight,
I unwrap inputs through day and night,
Schemas transform — I twitch my nose,
Routes revealed where inference grows,
Hooray! a rabbit's tiny type-joys rite.

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Export RouteInput type' clearly and concisely describes the main change—exposing RouteInput types to the public API to enable type inference improvements in elysia/eden.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

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

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@src/index.ts`:
- Around line 230-231: The current type alias RoutesInput (declared as RouteBase
& InferRouteInput<Routes>) is being lost during composition because downstream
signatures derive from StripRouteInput<Routes> (i.e., NewElysia['~Routes'])
which strips input metadata; update the composition return types to explicitly
thread and merge RoutesInput (e.g., merge with NewElysia['~RoutesInput'])
instead of re-deriving only from StripRouteInput<Routes>, and adjust affected
composition helpers (use, group, guard and any functions producing NewElysia) so
they carry and combine NewElysia['~RoutesInput'] alongside NewElysia['~Routes']
to preserve route-input metadata across merges.

---

ℹ️ Review info

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between bbaf6b7 and cdbdbaa.

📒 Files selected for processing (3)

• src/index.ts
• src/types.ts
• test/types/routes-input.ts

[thadeucity]

Solves #1748

[thadeucity]

Added Code Rabbit suggestion

[coderabbitai]

🧹 Nitpick comments (1)

src/index.ts (1)

5798-5803: Consider extracting a helper alias for repeated route-input unwrapping.

The repeated UnwrapRouteInput<Input, Definitions['typebox'], JoinPath<BasePath, Path>> pattern across handlers is correct but verbose; a local type alias would reduce duplication and drift risk.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@src/index.ts` around lines 5798 - 5803, Create a local type alias to reduce
repeated verbosity of UnwrapRouteInput by declaring something like
RouteInput<Input, Path> = UnwrapRouteInput<Input, Definitions['typebox'],
JoinPath<BasePath, Path>> near the handlers; then replace occurrences of
UnwrapRouteInput<Input, Definitions['typebox'], JoinPath<BasePath, Path>> with
the new alias (referencing the existing symbols UnwrapRouteInput,
Definitions['typebox'], JoinPath, BasePath, Path) so all handlers use the
shorter RouteInput alias and avoid duplication.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@src/index.ts`:
- Around line 5798-5803: Create a local type alias to reduce repeated verbosity
of UnwrapRouteInput by declaring something like RouteInput<Input, Path> =
UnwrapRouteInput<Input, Definitions['typebox'], JoinPath<BasePath, Path>> near
the handlers; then replace occurrences of UnwrapRouteInput<Input,
Definitions['typebox'], JoinPath<BasePath, Path>> with the new alias
(referencing the existing symbols UnwrapRouteInput, Definitions['typebox'],
JoinPath, BasePath, Path) so all handlers use the shorter RouteInput alias and
avoid duplication.

---

ℹ️ Review info

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between cdbdbaa and 4ef7494.

📒 Files selected for processing (1)

• src/index.ts