feat: readValidatedBody and getValidatedQuery utils

README.md

@@ -168,11 +168,13 @@ H3 has a concept of composable utilities that accept `event` (from `eventHandler
 
 - `readRawBody(event, encoding?)`
 - `readBody(event)`
+- `readValidatedBody(event, validate)`
 - `readMultipartFormData(event)`
 
 #### Request
 
 - `getQuery(event)`
+- `getValidatedBody(event, validate)`
 - `getRouterParams(event)`
 - `getMethod(event, default?)`
 - `isMethod(event, expected, allowHead?)`

package.json

@@ -58,7 +58,8 @@
     "supertest": "^6.3.3",
     "typescript": "^5.1.6",
     "unbuild": "^1.2.1",
-    "vitest": "^0.33.0"
+    "vitest": "^0.33.0",
+    "zod": "^3.21.4"
   },
   "packageManager": "pnpm@8.6.9"
 }

src/types.ts

@@ -1,6 +1,11 @@
 import type { H3Event } from "./event";
 import { Session } from "./utils/session";
 
+export type {
+  ValidateFunction,
+  ValidateResult,
+} from "./utils/internal/validate";
+
 // https://www.rfc-editor.org/rfc/rfc7231#section-4.1
 export type HTTPMethod =
   | "GET"

src/utils/body.ts

@@ -5,6 +5,7 @@ import type { H3Event } from "../event";
 import { createError } from "../error";
 import { parse as parseMultipartData } from "./internal/multipart";
 import { assertMethod, getRequestHeader } from "./request";
+import { ValidateFunction, validateData } from "./internal/validate";
 
 export type { MultiPartData } from "./internal/multipart";
 
@@ -118,6 +119,14 @@ export async function readBody<T = any>(
   return parsed;
 }
 
+export async function readValidatedBody<T>(
+  event: H3Event,
+  validate: ValidateFunction<T>
+): Promise<T> {
+  const _body = await readBody(event, { strict: true });
+  return validateData(_body, validate);
+}
+
 export async function readMultipartFormData(event: H3Event) {
   const contentType = getRequestHeader(event, "content-type");
   if (!contentType || !contentType.startsWith("multipart/form-data")) {

src/utils/internal/validate.ts

@@ -0,0 +1,36 @@
+import { createError } from "../../error";
+
+// TODO: Consider using similar method of typeschema for external library compatibility
+// https://github.com/decs/typeschema/blob/v0.1.3/src/assert.ts
+
+export type ValidateResult<T> = T | true | false | void;
+
+export type ValidateFunction<T> = (
+  data: unknown
+) => ValidateResult<T> | Promise<ValidateResult<T>>;
+
+export async function validateData<T>(
+  data: unknown,
+  fn: ValidateFunction<T>
+): Promise<T> {
+  try {
+    const res = await fn(data);
+    if (res === false) {
+      throw createValidationError();
+    }
+    if (res === true) {
+      return data as T;
+    }
+    return res ?? (data as T);
+  } catch (error) {
+    throw createValidationError(error);
+  }
+}
+
+function createValidationError(validateError?: any) {
+  throw createError({
+    status: 400,
+    message: validateError.message || "Validation Failed",
+    ...validateError,
+  });
+}

src/utils/request.ts

@@ -2,11 +2,20 @@ import { getQuery as _getQuery } from "ufo";
 import { createError } from "../error";
 import type { HTTPMethod, RequestHeaders } from "../types";
 import type { H3Event } from "../event";
+import { validateData, ValidateFunction } from "./internal/validate";
 
 export function getQuery(event: H3Event) {
   return _getQuery(event.path || "");
 }
 
+export function getValidatedQuery<T>(
+  event: H3Event,
+  validate: ValidateFunction<T>
+): Promise<T> {
+  const query = getQuery(event);
+  return validateData(query, validate);
+}
+
 export function getRouterParams(
   event: H3Event
 ): NonNullable<H3Event["context"]["params"]> {

test/validate.test.ts

@@ -0,0 +1,146 @@
+import supertest, { SuperTest, Test } from "supertest";
+import { describe, it, expect, beforeEach } from "vitest";
+import { z } from "zod";
+import {
+  createApp,
+  toNodeListener,
+  App,
+  eventHandler,
+  readValidatedBody,
+  getValidatedQuery,
+  ValidateFunction,
+} from "../src";
+
+// Custom validator
+const customValidate: ValidateFunction<{
+  invalidKey: never;
+  default: string;
+  field?: string;
+}> = (data: any) => {
+  if (data.invalid) {
+    throw new Error("Invalid key");
+  }
+  data.default = "default";
+  return data;
+};
+
+// Zod validator (example)
+const zodValidate = z.object({
+  default: z.string().default("default"),
+  field: z.string().optional(),
+  invalid: z.never().optional() /* WTF! */,
+}).parse;
+
+describe("Validate", () => {
+  let app: App;
+  let request: SuperTest<Test>;
+
+  beforeEach(() => {
+    app = createApp({ debug: true });
+    request = supertest(toNodeListener(app));
+  });
+
+  describe("readValidatedBody", () => {
+    beforeEach(() => {
+      app.use(
+        "/custom",
+        eventHandler(async (event) => {
+          console.log(event.headers);
+          const data = await readValidatedBody(event, customValidate);
+          return data;
+        })
+      );
+
+      app.use(
+        "/zod",
+        eventHandler(async (event) => {
+          const data = await readValidatedBody(event, zodValidate);
+          return data;
+        })
+      );
+    });
+
+    describe("custom validator", () => {
+      it("Valid JSON", async () => {
+        const res = await request.post("/custom").send({ field: "value" });
+        expect(res.body).toEqual({ field: "value", default: "default" });
+        expect(res.status).toEqual(200);
+      });
+
+      it("Valid x-www-form-urlencoded", async () => {
+        const res = await request
+          .post("/custom")
+          .set("Content-Type", "application/x-www-form-urlencoded")
+          .send("field=value");
+        expect(res.body).toEqual({ field: "value", default: "default" });
+        expect(res.status).toEqual(200);
+      });
+
+      it("Invalid JSON", async () => {
+        const res = await request.post("/custom").send({ invalid: true });
+        expect(res.text).include("Invalid key");
+        expect(res.status).toEqual(400);
+      });
+    });
+
+    describe("zod validator", () => {
+      it("Valid", async () => {
+        const res = await request.post("/zod").send({ field: "value" });
+        expect(res.body).toEqual({ field: "value", default: "default" });
+        expect(res.status).toEqual(200);
+      });
+
+      it("Invalid", async () => {
+        const res = await request.post("/zod").send({ invalid: true });
+        expect(res.status).toEqual(400);
+      });
+    });
+  });
+
+  describe("getQuery", () => {
+    beforeEach(() => {
+      app.use(
+        "/custom",
+        eventHandler(async (event) => {
+          const data = await getValidatedQuery(event, customValidate);
+          return data;
+        })
+      );
+
+      app.use(
+        "/zod",
+        eventHandler(async (event) => {
+          const data = await getValidatedQuery(event, zodValidate);
+          return data;
+        })
+      );
+    });
+
+    describe("custom validator", () => {
+      it("Valid", async () => {
+        const res = await request.get("/custom?field=value");
+        expect(res.body).toEqual({ field: "value", default: "default" });
+        expect(res.status).toEqual(200);
+      });
+
+      it("Invalid", async () => {
+        const res = await request.get("/custom?invalid=true");
+        expect(res.text).include("Invalid key");
+        expect(res.status).toEqual(400);
+      });
+    });
+
+    describe("zod validator", () => {
+      it("Valid", async () => {
+        const res = await request.get("/zod?field=value");
+        expect(res.body).toEqual({ field: "value", default: "default" });
+        expect(res.status).toEqual(200);
+      });
+
+      it("Invalid", async () => {
+        const res = await request.get("/zod?invalid=true");
+        expect(res.status).toEqual(400);
+      });
+    });
+  });
+});