fix(protocols-trpc): apply controller pipes to client input arguments

.changeset/trpc-controller-input-pipes.md

@@ -0,0 +1,8 @@
+---
+"@croco/protocols-trpc": patch
+"@croco/problems-core": patch
+---
+
+Run controller and method pipes on tRPC body, path, query, and header arguments inside the request lifecycle, preserving context arguments and reporting pipe failures through the existing Problem/filter pipeline.
+
+Keep generated tRPC Problem diagnostic source locations synchronized with the pipe-enabled request lifecycle.

docs/problem-code-registry.json

@@ -1,3 +1,3 @@
 {
   "version": "croco.problem-code-registry.v1",
   "problemCount": 981,
@@ -22536,7 +22536,7 @@
       "sources": [
         {
           "file": "packages/protocols-trpc/src/libs/createTrpcRouter.ts",
-          "line": 92,
+          "line": 99,
           "column": 1,
           "kind": "problem-class"
         }
@@ -22566,7 +22566,7 @@
       "sources": [
         {
           "file": "packages/protocols-trpc/src/libs/createTrpcRouter.ts",
-          "line": 216,
+          "line": 224,
           "column": 13,
           "kind": "problem-factory"
         }
@@ -22596,7 +22596,7 @@
       "sources": [
         {
           "file": "packages/protocols-trpc/src/libs/createTrpcRouter.ts",
-          "line": 76,
+          "line": 83,
           "column": 1,
           "kind": "problem-class"
         }
@@ -22686,7 +22686,7 @@
       "sources": [
         {
           "file": "packages/protocols-trpc/src/libs/createTrpcRouter.ts",
-          "line": 63,
+          "line": 70,
           "column": 1,
           "kind": "problem-class"
         }

packages/docs/src/content/docs/en/reference/problem-recovery-cookbook.md

@@ -14513,7 +14513,7 @@ Sources:
 
 Sources:
 
-- `packages/protocols-trpc/src/libs/createTrpcRouter.ts:92:1` (problem-class)
+- `packages/protocols-trpc/src/libs/createTrpcRouter.ts:99:1` (problem-class)
 
 <a id="protocols-trpc-execution-context-missing"></a>
 
@@ -14531,7 +14531,7 @@ Sources:
 
 Sources:
 
-- `packages/protocols-trpc/src/libs/createTrpcRouter.ts:216:13` (problem-factory)
+- `packages/protocols-trpc/src/libs/createTrpcRouter.ts:224:13` (problem-factory)
 
 <a id="protocols-trpc-provider-container-required"></a>
 
@@ -14549,7 +14549,7 @@ Sources:
 
 Sources:
 
-- `packages/protocols-trpc/src/libs/createTrpcRouter.ts:76:1` (problem-class)
+- `packages/protocols-trpc/src/libs/createTrpcRouter.ts:83:1` (problem-class)
 
 <a id="protocols-trpc-request-normalization-failed"></a>
 
@@ -14603,7 +14603,7 @@ Sources:
 
 Sources:
 
-- `packages/protocols-trpc/src/libs/createTrpcRouter.ts:63:1` (problem-class)
+- `packages/protocols-trpc/src/libs/createTrpcRouter.ts:70:1` (problem-class)
 
 <a id="ratelimit-core-duplicate-default-policy"></a>
 

packages/problems-core/src/generated/problem-code-registry.ts

@@ -1,3 +1,3 @@
 import type { TypedProblemDetails } from "../libs/Problem";
 import type { ProblemCodeRegistry } from "../libs/ProblemRegistry";
 
@@ -23461,7 +23461,7 @@
       sources: [
         {
           file: "packages/protocols-trpc/src/libs/createTrpcRouter.ts",
-          line: 92,
+          line: 99,
           column: 1,
           kind: "problem-class",
         },
@@ -23494,7 +23494,7 @@
       sources: [
         {
           file: "packages/protocols-trpc/src/libs/createTrpcRouter.ts",
-          line: 216,
+          line: 224,
           column: 13,
           kind: "problem-factory",
         },
@@ -23527,7 +23527,7 @@
       sources: [
         {
           file: "packages/protocols-trpc/src/libs/createTrpcRouter.ts",
-          line: 76,
+          line: 83,
           column: 1,
           kind: "problem-class",
         },
@@ -23625,7 +23625,7 @@
       sources: [
         {
           file: "packages/protocols-trpc/src/libs/createTrpcRouter.ts",
-          line: 63,
+          line: 70,
           column: 1,
           kind: "problem-class",
         },

packages/protocols-trpc/README.md

@@ -55,6 +55,17 @@ The location schemas run before the controller method. `@Ctx()` and `@Raw()` bot
 unmodified tRPC procedure context and are not client input. For HTTP adapters, include the raw
 request or other transport envelope fields in `createContext` when a controller needs them.
 
+`@UsePipes` runs class pipes before method pipes on each body, path, query, or header argument,
+inside the interceptor-wrapped handler and the Croco request DI boundary. Async transformations
+are awaited; pipe failures reach the existing Problem/filter pipeline. Pipes receive REST
+argument metadata (`body`, `param`, `query`, or `header`, plus the parameter name when declared).
+Context and authentication arguments are preserved.
+
+tRPC validates its input schema before running these pipes. HTTP runs route pipes before
+parameter-level validation pipes, while contract-bound path/query schemas are parsed before
+route pipes. A tRPC pipe therefore receives schema-parsed input and cannot repair input that
+the tRPC schema rejects. The existing body-only and location-envelope shapes are preserved.
+
 ## Verification
 
 ```bash

packages/protocols-trpc/src/libs/createTrpcRouter.ts

@@ -3,7 +3,14 @@ import type { RequestContext } from "@croco/framework-context";
 import { Problem, ProblemCategory, ProblemFactory } from "@croco/problems-core";
 import type { RouteContractSourceLocation, RouteIR } from "@croco/protocols-core";
 import { extractRouteIR } from "@croco/protocols-core";
-import { getFilters, getGuards, getInterceptors, type Constructor } from "@croco/protocols-rest";
+import {
+  getFilters,
+  getGuards,
+  getInterceptors,
+  getPipes,
+  type Constructor,
+  type PipeTransform,
+} from "@croco/protocols-rest";
 import {
   type AnyProcedure,
   type AnyRouter,
@@ -170,6 +177,7 @@ function createProcedure(
   const guardProviders = getGuards(controller, route.methodName);
   const filterProviders = getFilters(controller, route.methodName);
   const interceptorProviders = getInterceptors(controller, route.methodName);
+  const pipeProviders = getPipes(controller, route.methodName);
   const createFilters = (): TrpcPipelineConfig["filters"] =>
     filterProviders.map((provider) => instantiateProvider(provider, options));
   const createGuards = (): TrpcPipelineConfig["guards"] =>
@@ -221,7 +229,14 @@ function createProcedure(
 
     return executionPipeline.runInterceptors(
       context,
-      async () => callRoute(controllerInstance, route, input, ctx),
+      async () =>
+        callRoute(
+          controllerInstance,
+          route,
+          input,
+          ctx,
+          pipeProviders.map((provider) => instantiateProvider(provider, options)),
+        ),
       createInterceptors(),
     );
   };
@@ -233,19 +248,41 @@ function createProcedure(
   return procedure.mutation(resolver);
 }
 
-function callRoute(
+async function callRoute(
   controllerInstance: object,
   route: RouteIR,
   input: unknown,
   context: unknown,
-): unknown {
+  pipes: readonly PipeTransform[],
+): Promise<unknown> {
   const handler = Reflect.get(controllerInstance, route.methodName);
 
   if (!isRouteHandler(handler)) {
     throw new TrpcRouteHandlerError(route.methodName);
   }
 
-  return handler.apply(controllerInstance, resolveTrpcRouteParams(route, input, context));
+  const args = resolveTrpcRouteParams(route, input, context);
+  for (const [position, param] of route.params.entries()) {
+    if (
+      param.kind !== "body" &&
+      param.kind !== "path" &&
+      param.kind !== "query" &&
+      param.kind !== "header"
+    ) {
+      continue;
+    }
+
+    const index = param.index ?? position;
+    const metadata = {
+      type: param.kind === "path" ? ("param" as const) : param.kind,
+      ...(param.name ? { name: param.name } : {}),
+    };
+    for (const pipe of pipes) {
+      args[index] = await pipe.transform(args[index], metadata);
+    }
+  }
+
+  return handler.apply(controllerInstance, args);
 }
 
 function getDomainName(route: RouteIR): string {