fix ZodType input/output issue

Author: omermecitoglu

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@omer-x/next-openapi-route-handler",
-  "version": "0.3.1",
+  "version": "0.4.0",
   "description": "a Next.js plugin to generate OpenAPI documentation from route handlers",
   "keywords": [
     "next.js",
@@ -44,7 +44,7 @@
   },
   "devDependencies": {
     "@omer-x/eslint-config": "^1.0.7",
-    "@omer-x/openapi-types": "^0.1.1",
+    "@omer-x/openapi-types": "^0.1.2",
     "@types/node": "^20.14.2",
     "eslint": "^8.57.0",
     "ts-unused-exports": "^10.1.0",

package.json

@@ -2,9 +2,9 @@ import type { HttpMethod } from "~/types/http";
 import type { FixedRequest } from "~/types/request";
 import { resolveContent } from "./content";
 import type { RequestBodyObject } from "@omer-x/openapi-types/request-body";
-import type { ZodError, ZodType } from "zod";
+import type { ZodError, ZodType, ZodTypeDef } from "zod";
 
-export function resolveRequestBody(source?: ZodType<unknown> | string, isFormData: boolean = false) {
+export function resolveRequestBody<I, O>(source?: ZodType<O, ZodTypeDef, I> | string, isFormData: boolean = false) {
   if (!source) return undefined;
   return {
     // description: "", // how to fill this?
@@ -13,12 +13,12 @@ export function resolveRequestBody(source?: ZodType<unknown> | string, isFormDat
   } as RequestBodyObject;
 }
 
-export async function parseRequestBody<B>(
-  request: FixedRequest<B>,
+export async function parseRequestBody<I, O>(
+  request: FixedRequest<NoInfer<I>>,
   method: HttpMethod,
-  schema?: ZodType<B> | string,
+  schema?: ZodType<O, ZodTypeDef, I> | string,
   isFormData: boolean = false
-) {
+): Promise<O | null> {
   if (!schema || typeof schema === "string") return null;
   if (method === "GET") throw new Error("GET routes can't have request body");
   if (isFormData) {

src/core/body.ts

@@ -1,7 +1,7 @@
 import { safeParse } from "./zod-error-handler";
-import type { ZodError, ZodType } from "zod";
+import type { ZodError, ZodType, ZodTypeDef } from "zod";
 
-export default function parsePathParams<T>(source?: T, schema?: ZodType<T>) {
+export default function parsePathParams<I, O>(source?: I, schema?: ZodType<O, ZodTypeDef, I>) {
   if (!schema || !source) return null;
   try {
     return safeParse(schema, source as Record<string, unknown>);

src/core/path-params.ts

@@ -1,5 +1,5 @@
 import { safeParse } from "./zod-error-handler";
-import type { ZodError, ZodType } from "zod";
+import type { ZodError, ZodType, ZodTypeDef } from "zod";
 
 function serializeArray(value: string[]) {
   return value.join(",");
@@ -9,7 +9,7 @@ export function deserializeArray(value: string) {
   return value.split(",");
 }
 
-export default function parseSearchParams<T>(source: URLSearchParams, schema?: ZodType<T>) {
+export default function parseSearchParams<I, O>(source: URLSearchParams, schema?: ZodType<O, ZodTypeDef, I>) {
   if (!schema) return null;
   const sourceKeys = Array.from(new Set(source.keys()));
   const params = sourceKeys.reduce((collection, key) => {

src/core/search-params.ts

@@ -1,5 +1,5 @@
 import { deserializeArray } from "./search-params";
-import type { ZodType } from "zod";
+import type { ZodType, ZodTypeDef } from "zod";
 
 function convertStringToNumber(input: Record<string, unknown>, keys: string[]) {
   return keys.reduce((mutation, key) => {
@@ -25,7 +25,7 @@ function convertStringToArray(input: Record<string, unknown>, keys: string[]) {
   }, input);
 }
 
-export function safeParse<T>(schema: ZodType<T>, input: Record<string, unknown>) {
+export function safeParse<I, O>(schema: ZodType<O, ZodTypeDef, I>, input: Record<string, unknown>) {
   const result = schema.safeParse(input);
   if (!result.success) {
     for (const issue of result.error.issues) {

src/core/zod-error-handler.ts

@@ -1,4 +1,3 @@
-import { type ZodType } from "zod";
 import { parseRequestBody, resolveRequestBody } from "./core/body";
 import { resolveParams } from "./core/params";
 import parsePathParams from "./core/path-params";
@@ -7,6 +6,7 @@ import parseSearchParams from "./core/search-params";
 import type { HttpMethod } from "./types/http";
 import type { RouteHandler, RouteMethodHandler } from "./types/next";
 import type { ResponseDefinition } from "./types/response";
+import type { ZodType, ZodTypeDef } from "zod";
 
 type ActionSource<PathParams, QueryParams, RequestBody> = {
   pathParams: PathParams,
@@ -20,31 +20,39 @@ type RouteWithoutBody = {
   hasFormData?: boolean,
 };
 
-type RouteWithBody<Body> = {
+type RouteWithBody<I, O> = {
   method: Exclude<HttpMethod, "GET" | "DELETE" | "HEAD">,
-  requestBody?: ZodType<Body> | string,
+  requestBody?: ZodType<O, ZodTypeDef, I> | string,
   hasFormData?: boolean,
 };
 
-type RouteOptions<Method, PathParams, QueryParams, RequestBody> = {
+type RouteOptions<
+  Method,
+  PathParamsInput,
+  PathParamsOutput,
+  QueryParamsInput,
+  QueryParamsOutput,
+  RequestBodyInput,
+  RequestBodyOutput,
+> = {
   operationId: string,
   method: Method,
   summary: string,
   description: string,
   tags: string[],
-  pathParams?: ZodType<PathParams>,
-  queryParams?: ZodType<QueryParams>,
-  action: (source: ActionSource<PathParams, QueryParams, RequestBody>) => Response | Promise<Response>,
+  pathParams?: ZodType<PathParamsOutput, ZodTypeDef, PathParamsInput>,
+  queryParams?: ZodType<QueryParamsOutput, ZodTypeDef, QueryParamsInput>,
+  action: (source: ActionSource<PathParamsOutput, QueryParamsOutput, RequestBodyOutput>) => Response | Promise<Response>,
   responses: Record<string, ResponseDefinition>,
-} & (RouteWithBody<RequestBody> | RouteWithoutBody);
+} & (RouteWithBody<RequestBodyInput, RequestBodyOutput> | RouteWithoutBody);
 
-export default function createRoute<M extends HttpMethod, PP, QP, RB>(input: RouteOptions<M, PP, QP, RB>) {
-  const handler: RouteMethodHandler<PP> = async (request, props) => {
+function createRoute<M extends HttpMethod, PPI, PPO, QPI, QPO, RBI, RBO>(input: RouteOptions<M, PPI, PPO, QPI, QPO, RBI, RBO>) {
+  const handler: RouteMethodHandler<PPI> = async (request, props) => {
     try {
       const { searchParams } = new URL(request.url);
-      const pathParams = parsePathParams<PP>(props.params, input.pathParams) as PP;
-      const queryParams = parseSearchParams(searchParams, input.queryParams) as QP;
-      const body = await parseRequestBody(request, input.method, input.requestBody ?? undefined, input.hasFormData) as RB;
+      const pathParams = parsePathParams(props.params, input.pathParams) as PPO;
+      const queryParams = parseSearchParams(searchParams, input.queryParams) as QPO;
+      const body = await parseRequestBody(request, input.method, input.requestBody ?? undefined, input.hasFormData) as RBO;
       return await input.action({ pathParams, queryParams, body });
     } catch (error) {
       if (error instanceof Error) {
@@ -83,5 +91,7 @@ export default function createRoute<M extends HttpMethod, PP, QP, RB>(input: Rou
     responses: responses,
   };
 
-  return { [input.method]: handler } as RouteHandler<M, PP>;
+  return { [input.method]: handler } as RouteHandler<M, PPI>;
 }
+
+export default createRoute;

src/index.ts

@@ -5,13 +5,13 @@ type RouteHandlerProps<PathParams> = {
   params?: PathParams,
 };
 
-export type RouteMethodHandler<PathParams> = ((
+export type RouteMethodHandler<PathParamsInput> = ((
   request: Request,
-  props: RouteHandlerProps<PathParams>
+  props: RouteHandlerProps<PathParamsInput>
 ) => Promise<Response>) & {
   apiData?: OperationObject,
 };
 
-export type RouteHandler<HM extends HttpMethod, PathParams> = {
-  [key in HM]: RouteMethodHandler<PathParams>;
+export type RouteHandler<HM extends HttpMethod, PathParamsInput> = {
+  [key in HM]: RouteMethodHandler<PathParamsInput>;
 };

src/types/next.ts

@@ -1,5 +1,5 @@
-export interface FixedRequest<RequestBody> {
+export interface FixedRequest<RequestBodyInput> {
   url: string,
-  json: () => Promise<RequestBody>,
+  json: () => Promise<RequestBodyInput>,
   formData: () => Promise<FormData>,
 }