Refine type

examples/express/express.ts

@@ -27,40 +27,40 @@ const newApp = () => {
 
     // validate method is available in res.locals
     // validate(req).query() is equals to pathMap["/users"]["get"].query.safeParse(req.query)
-    const r = res.locals.validate(req).query();
-    if (r.success) {
+    const { data, error } = res.locals.validate(req).query();
+    if (data !== undefined) {
       // res.status(200).json() accepts only the response schema defined in pathMap["/users"]["get"].res["200"]
-      res.status(200).json({ userNames: [`page${r.data.page}#user1`] });
+      res.status(200).json({ userNames: [`page${data.page}#user1`] });
     } else {
       // res.status(400).json() accepts only the response schema defined in pathMap["/users"]["get"].res["400"]
-      res.status(400).json({ errorMessage: r.error.toString() });
+      res.status(400).json({ errorMessage: error.toString() });
     }
   });
   wApp.post("/users", (req, res) => {
     // validate(req).body() is equals to pathMap["/users"]["post"].body.safeParse(req.body)
-    const r = res.locals.validate(req).body();
+    const { data, error } = res.locals.validate(req).body();
     {
       // Request header also can be validated
       res.locals.validate(req).headers();
     }
-    if (r.success) {
+    if (data !== undefined) {
       // res.status(200).json() accepts only the response schema defined in pathMap["/users"]["post"].res["200"]
-      res.status(200).json({ userId: r.data.userName + "#0" });
+      res.status(200).json({ userId: data.userName + "#0" });
     } else {
       // res.status(400).json() accepts only the response schema defined in pathMap["/users"]["post"].res["400"]
-      res.status(400).json({ errorMessage: r.error.toString() });
+      res.status(400).json({ errorMessage: error.toString() });
     }
   });
 
   const getUserHandler: Handlers["/users/:userId"]["get"] = (req, res) => {
-    const params = res.locals.validate(req).params();
+    const { data: params, error } = res.locals.validate(req).params();
 
-    if (params.success) {
+    if (params !== undefined) {
       // res.status(200).json() accepts only the response schema defined in pathMap["/users/:userId"]["get"].res["200"]
-      res.status(200).json({ userName: "user#" + params.data.userId });
+      res.status(200).json({ userName: "user#" + params.userId });
     } else {
       // res.status(400).json() accepts only the response schema defined in pathMap["/users/:userId"]["get"].res["400"]
-      res.status(400).json({ errorMessage: params.error.toString() });
+      res.status(400).json({ errorMessage: error.toString() });
     }
   };
   wApp.get("/users/:userId", getUserHandler);

src/common/spec.ts

@@ -36,7 +36,24 @@ type AsJsonApiEndpoint<AE extends ApiEndpoint> = {
 export type ApiEndpoints = { [Path in string]: ApiEndpoint };
 export type AnyApiEndpoints = { [Path in string]: AnyApiEndpoint };
 
-export interface ApiSpec<
+export interface BaseApiSpec<
+  Params,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  Query,
+  Body,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  ResBody,
+  RequestHeaders,
+  ResponseHeaders,
+> {
+  query?: Query;
+  params?: Params;
+  body?: Body;
+  resBody: ResBody;
+  headers?: RequestHeaders;
+  resHeaders?: ResponseHeaders;
+}
+export type ApiSpec<
   ParamKeys extends string = string,
   Params extends Record<ParamKeys, string | number> = Record<
     ParamKeys,
@@ -52,16 +69,9 @@ export interface ApiSpec<
   >,
   RequestHeaders extends Record<string, string> = Record<string, string>,
   ResponseHeaders extends Record<string, string> = Record<string, string>,
-> {
-  query?: Query;
-  params?: Params;
-  body?: Body;
-  resBody: ResBody;
-  headers?: RequestHeaders;
-  resHeaders?: ResponseHeaders;
-}
+> = BaseApiSpec<Params, Query, Body, ResBody, RequestHeaders, ResponseHeaders>;
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-export type AnyApiSpec = ApiSpec<string, any, any, any, any, any, any>;
+export type AnyApiSpec = BaseApiSpec<any, any, any, any, any, any>;
 
 type JsonHeader = {
   "Content-Type": "application/json";
@@ -89,6 +99,21 @@ export type ApiP<
     : never
   : never;
 
+export type ApiHasP<
+  E extends ApiEndpoints,
+  Path extends keyof E & string,
+  M extends Method,
+> = E[Path] extends ApiEndpoint
+  ? E[Path][M] extends ApiSpec<ParseUrlParams<Path>>
+    ? // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      E[Path][M]["body"] extends Record<string, any>
+      ? true
+      : E[Path][M]["headers"] extends Record<string, string>
+        ? true
+        : false
+    : never
+  : never;
+
 export type ApiRes<
   AResponses extends ApiResponses,
   SC extends keyof AResponses & StatusCode,

src/common/validate.ts

@@ -2,6 +2,33 @@ import { Result } from "../utils";
 import { AnyApiEndpoint, AnyApiEndpoints, isMethod } from "./spec";
 import { ParsedQs } from "qs";
 
+export type Validators<
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  ParamsValidator extends AnyValidator | never,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  QueryValidator extends AnyValidator | never,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  BodyValidator extends AnyValidator | never,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  HeadersValidator extends AnyValidator | never,
+> = {
+  // FIXME: FilterNeverにしたい
+  params: ParamsValidator;
+  query: QueryValidator;
+  body: BodyValidator;
+  headers: HeadersValidator;
+};
+export type AnyValidators = Validators<
+  AnyValidator | never,
+  AnyValidator | never,
+  AnyValidator | never,
+  AnyValidator | never
+>;
+
+export type Validator<Data, Error> = () => Result<Data, Error>;
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type AnyValidator = Validator<any, any>;
+
 export type ValidatorsInput = {
   path: string;
   method: string;

src/express/index.test.ts

@@ -1,9 +1,14 @@
 import { describe, it, expect, vi } from "vitest";
 import request from "supertest";
 import express from "express";
-import { asAsync, typed, ValidateLocals, validatorMiddleware } from "./index";
+import {
+  asAsync,
+  typed,
+  ZodValidateLocals,
+  validatorMiddleware,
+} from "./index";
 import { ZodApiEndpoints } from "../zod";
-import { z } from "zod";
+import { z, ZodError } from "zod";
 import { Request } from "express";
 import { ParseUrlParams } from "../common";
 
@@ -55,23 +60,29 @@ describe("validatorMiddleware", () => {
       middleware(req as Request, res, next);
       expect(next).toHaveBeenCalled();
       expect(res.locals.validate).toEqual(expect.any(Function));
-      const locals = res.locals as ValidateLocals<
+      const locals = res.locals as ZodValidateLocals<
         (typeof pathMap)["/"]["get"],
         ParseUrlParams<"/">
       >;
       const validate = locals.validate(req as Request);
 
-      const query = validate.query();
-      expect(query.success).toBe(true);
-      expect(query.data!.name).toBe("alice");
+      {
+        const r = validate.query();
+        expect(r.error).toBeUndefined();
+        expect(r.data?.name).toBe("alice");
+      }
 
-      const body = validate.body();
-      expect(body.success).toBe(true);
-      expect(body.data!.name).toBe("alice");
+      {
+        const r = validate.body();
+        expect(r.error).toBeUndefined();
+        expect(r.data?.name).toBe("alice");
+      }
 
-      const headers = validate.headers();
-      expect(headers.success).toBe(true);
-      expect(headers.data!["content-type"]).toBe("application/json");
+      {
+        const r = validate.headers();
+        expect(r.error).toBeUndefined();
+        expect(r.data?.["content-type"]).toBe("application/json");
+      }
     });
 
     it("should fail if request schema is invalid", () => {
@@ -89,21 +100,57 @@ describe("validatorMiddleware", () => {
       middleware(req as Request, res, next);
       expect(next).toHaveBeenCalled();
       expect(res.locals.validate).toEqual(expect.any(Function));
-      const locals = res.locals as ValidateLocals<
+      const locals = res.locals as ZodValidateLocals<
         (typeof pathMap)["/"]["get"],
         ParseUrlParams<"/">
       >;
       const validate = locals.validate(req as Request);
 
-      console.log("validate", validate);
-      const query = validate.query();
-      expect(query.success).toBe(false);
+      {
+        const r = validate.query();
+        expect(r.error).toEqual(
+          new ZodError([
+            {
+              code: "invalid_type",
+              expected: "string",
+              received: "undefined",
+              path: ["name"],
+              message: "Required",
+            },
+          ]),
+        );
+        expect(r.data).toBeUndefined();
+      }
 
-      const body = validate.body();
-      expect(body.success).toBe(false);
+      {
+        const r = validate.body();
+        expect(r.error).toEqual(
+          new ZodError([
+            {
+              code: "invalid_type",
+              expected: "string",
+              received: "undefined",
+              path: ["name"],
+              message: "Required",
+            },
+          ]),
+        );
+        expect(r.data).toBeUndefined();
+      }
 
-      const headers = validate.headers();
-      expect(headers.success).toBe(false);
+      const r = validate.headers();
+      expect(r.error).toEqual(
+        new ZodError([
+          {
+            code: "invalid_literal",
+            expected: "application/json",
+            received: undefined,
+            path: ["content-type"],
+            message: `Invalid literal value, expected "application/json"`,
+          },
+        ]),
+      );
+      expect(r.data).toBeUndefined();
     });
   });
 
@@ -123,10 +170,8 @@ describe("validatorMiddleware", () => {
       middleware(req as unknown as Request, res, next);
       expect(next).toHaveBeenCalled();
       expect(res.locals.validate).toEqual(expect.any(Function));
-      const locals = res.locals as ValidateLocals<
-        undefined,
-        ParseUrlParams<"">
-      >;
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const locals = res.locals as ZodValidateLocals<any, ParseUrlParams<"">>;
       const validate = locals.validate(req as Request);
 
       const query = validate.query;
@@ -157,10 +202,8 @@ describe("validatorMiddleware", () => {
       middleware(req as unknown as Request, res, next);
       expect(next).toHaveBeenCalled();
       expect(res.locals.validate).toEqual(expect.any(Function));
-      const locals = res.locals as ValidateLocals<
-        undefined,
-        ParseUrlParams<"">
-      >;
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const locals = res.locals as ZodValidateLocals<any, ParseUrlParams<"">>;
       const validate = locals.validate(req as Request);
 
       const query = validate.query;
@@ -220,19 +263,19 @@ describe("typed", () => {
       return res.json([{ id: "1", name: "alice" }]);
     });
     wApp.post("/users", (req, res) => {
-      const body = res.locals.validate(req).body();
-      if (!body.success) {
+      const { data } = res.locals.validate(req).body();
+      if (data === undefined) {
         return res.status(400).json({ message: "invalid body" });
       }
-      return res.json({ id: "1", name: body.data.name });
+      return res.json({ id: "1", name: data.name });
     });
     wApp.get("/users/:id", (req, res) => {
       const qResult = res.locals.validate(req).query();
       const pResult = res.locals.validate(req).params();
-      if (!pResult.success) {
+      if (pResult.data === undefined) {
         return res.status(400).json({ message: "invalid query" });
       }
-      if (qResult.success) {
+      if (qResult.data !== undefined) {
         return res.status(200).json({ id: pResult.data.id, name: "alice" });
       }
       return res.status(200).json({ id: pResult.data.id, name: "alice" });

src/express/index.ts

@@ -19,6 +19,7 @@ import {
 import { StatusCode } from "../common";
 import { ParseUrlParams } from "../common";
 import { ParsedQs } from "qs";
+import { AnyValidators } from "../common/validate";
 
 /**
  * Express Request Handler, but with more strict type information.
@@ -46,7 +47,9 @@ export type ToHandler<
   M extends Method,
 > = Handler<
   ToApiEndpoints<ZodE>[Path][M],
-  ValidateLocals<ZodE[Path][M], ParseUrlParams<Path>>
+  ZodE[Path][M] extends ZodApiSpec
+    ? ZodValidateLocals<ZodE[Path][M], ParseUrlParams<Path>>
+    : Record<string, never>
 >;
 
 /**
@@ -75,16 +78,13 @@ export type ExpressResponse<
   ) => Response<ApiRes<Responses, SC>, LocalsObj, SC>;
 };
 
-export type ValidateLocals<
-  AS extends ZodApiSpec | undefined,
-  ParamKeys extends string,
-> = {
-  validate: (
-    req: Request<ParamsDictionary, unknown, unknown, unknown>,
-  ) => AS extends ZodApiSpec
-    ? ZodValidators<AS, ParamKeys>
-    : Record<string, never>;
+export type ValidateLocals<Vs extends AnyValidators | Record<string, never>> = {
+  validate: (req: Request<ParamsDictionary, unknown, unknown, unknown>) => Vs;
 };
+export type ZodValidateLocals<
+  AS extends ZodApiSpec,
+  ParamKeys extends string,
+> = ValidateLocals<ZodValidators<AS, ParamKeys>>;
 
 /**
  * Express Router, but with more strict type information.