fix(server): routing skips callable/actionable procedures (#1551)

Fixes #1545

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-->
## Summary by CodeRabbit

* **Tests**
* Added test coverage verifying traversal correctly finds callable
procedures augmented with metadata, including nested paths.
* **Refactor**
* Improved router-node validation during traversal to use a stricter
object check while preserving traversal behavior into nested routes.

[![Review Change
Stack](https://storage.googleapis.com/coderabbit_public_assets/review-stack-in-coderabbit-ui.svg)](https://app.coderabbit.ai/change-stack/middleapi/orpc/pull/1551)
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---------

Co-authored-by: GitHub Actions <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: 3 people

packages/server/src/router-utils.test.ts

@@ -176,6 +176,36 @@ describe('traverseContractProcedures', () => {
       path: ['nested', 'pong'],
     })
   })
+
+  it('with callable procedures', () => {
+    const callablePing = Object.assign(() => {}, {
+      '~orpc': ping['~orpc'],
+    })
+
+    const callablePong = Object.assign(() => {}, {
+      '~orpc': pong['~orpc'],
+    })
+
+    const router = { ping: callablePing, nested: { pong: callablePong } }
+
+    const callback = vi.fn()
+    expect(traverseContractProcedures({
+      router,
+      path: [],
+    }, callback)).toEqual([])
+
+    expect(callback).toHaveBeenCalledTimes(2)
+
+    expect(callback).toHaveBeenNthCalledWith(1, {
+      contract: router.ping,
+      path: ['ping'],
+    })
+
+    expect(callback).toHaveBeenNthCalledWith(2, {
+      contract: router.nested.pong,
+      path: ['nested', 'pong'],
+    })
+  })
 })
 
 it('resolveContractProcedures', async () => {

packages/server/src/router-utils.ts

@@ -5,6 +5,7 @@ import type { AnyMiddleware } from './middleware'
 import type { AnyProcedure } from './procedure'
 import type { AnyRouter } from './router'
 import { enhanceRoute, isContractProcedure, mergeErrorMap, mergePrefix } from '@orpc/contract'
+import { isTypescriptObject } from '@orpc/shared'
 import { getLazyMeta, isLazy, lazy, unlazy } from './lazy'
 import { mergeMiddlewares } from './middleware-utils'
 import { isProcedure, Procedure } from './procedure'
@@ -27,7 +28,7 @@ export function getRouter<T extends Lazyable<AnyRouter | undefined>>(
       return undefined as any
     }
 
-    if (typeof current !== 'object') {
+    if (!isTypescriptObject(current)) {
       return undefined as any
     }
 
@@ -192,16 +193,11 @@ export function traverseContractProcedures(
   callback: (options: TraverseContractProcedureCallbackOptions) => void,
   lazyOptions: LazyTraverseContractProceduresOptions[] = [],
 ): LazyTraverseContractProceduresOptions[] {
-  // Guard before reading the hidden-contract symbol so that null/undefined
-  // child exports don't crash in `getHiddenRouterContract`. Primitives like
-  // strings autobox safely; only null/undefined throw on symbol access.
-  if (typeof options.router !== 'object' || options.router === null) {
-    return lazyOptions
-  }
-
   let currentRouter: AnyContractRouter | Lazyable<AnyRouter> = options.router
 
-  const hiddenContract = getHiddenRouterContract(options.router)
+  const hiddenContract = isTypescriptObject(options.router)
+    ? getHiddenRouterContract(options.router)
+    : undefined
 
   if (hiddenContract !== undefined) {
     currentRouter = hiddenContract