bug(server): input matching { description?: string } breaks built p…

…rocedure (#5297)


---------

Co-authored-by: Alex / KATT <alexander@n1s.se>

examples/.test/internal-types-export/src/server.ts

@@ -16,11 +16,12 @@ const someMiddleware = t.middleware(({ next }) => {
   return next();
 });
 
-export function genericRouter<TSchema extends (value: any) => unknown>(schema: TSchema) {
-  return t.router({
-    foo: t.procedure.output(schema).query(() => 'bar'),
-  });
-}
+// Note, this is not valid in v11: https://github.com/trpc/trpc/pull/3831#discussion_r1450437174
+// export function genericRouter<TSchema extends (value: any) => unknown>(schema: TSchema) {
+//   return t.router({
+//     foo: t.procedure.output(schema).query(() => 'bar'),
+//   });
+// }
 
 export type Foo = { x: Foo | number };
 
@@ -34,7 +35,7 @@ const routerB = t.router({
 const appRouter = t.router({
   foo: t.procedure.query(() => 'bar'),
   hello: t.procedure.use(someMiddleware).query(() => 'hello'),
-  generic: genericRouter((value: string) => value.toUpperCase()),
+  // generic: genericRouter((value: string) => value.toUpperCase()),
   merged: t.mergeRouters(routerA, routerB),
   recursive: t.procedure.query(() => {
     return {

packages/core/src/procedureBuilder.ts

@@ -34,7 +34,7 @@ type ErrorMessage<TMessage extends string> = TMessage;
 /** @internal */
 export const unsetMarker = Symbol('unsetMarker');
 type UnsetMarker = typeof unsetMarker;
-type DefaultValue<TValue, TFallback> = UnsetMarker extends TValue
+type DefaultValue<TValue, TFallback> = TValue extends UnsetMarker
   ? TFallback
   : TValue;
 

packages/tests/server/regression/issue-5297-description-key-on-input-turns-to-void.test.ts

@@ -0,0 +1,49 @@
+import type { QueryProcedure } from '@trpc/core';
+import { initTRPC } from '@trpc/server';
+import * as z from 'zod';
+
+describe('Serialization of Record types', () => {
+  const t = initTRPC.create();
+  const appRouter = t.router({
+    withDescriptionKey: t.procedure
+      .input(
+        z.object({
+          description: z.string(),
+        }),
+      )
+      .query(({ input }) => {
+        expectTypeOf<{ description: string }>(input);
+        return { input };
+      }),
+    maybeDescriptionKey: t.procedure
+      .input(
+        z.object({
+          description: z.string().optional(),
+        }),
+      )
+      .query(({ input }) => {
+        expectTypeOf<{ description?: string }>(input);
+        return { input };
+      }),
+  });
+
+  test("Description key doesn't get matched on unsetMarker", async () => {
+    expectTypeOf<
+      QueryProcedure<{
+        input: {
+          description: string;
+        };
+        output: { input: { description: string } };
+      }>
+    >(appRouter.withDescriptionKey);
+
+    expectTypeOf<
+      QueryProcedure<{
+        input: {
+          description?: string | undefined;
+        };
+        output: { input: { description?: string | undefined } };
+      }>
+    >(appRouter.maybeDescriptionKey);
+  });
+});