feat: introduce tRPC server middleware (#36)

* feat: introduce tRPC server middleware

* chore: add changeset

.changeset/little-tips-end.md

@@ -0,0 +1,5 @@
+---
+'@hono/trpc-server': patch
+---
+
+Initial release

.github/workflows/ci-trpc-server.yml

@@ -0,0 +1,25 @@
+name: ci-trpc-server
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'packages/trpc-server/**'
+  pull_request:
+    branches: ['*']
+    paths:
+      - 'packages/trpc-server/**'
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./packages/trpc-server
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: 18.x
+      - run: yarn install --frozen-lockfile
+      - run: yarn build
+      - run: yarn test

package.json

@@ -12,6 +12,7 @@
     "build:graphql-server": "yarn workspace @hono/graphql-server build",
     "build:sentry": "yarn workspace @hono/sentry build",
     "build:firebase-auth": "yarn workspace @hono/firebase-auth build",
+    "build:trpc-server": "yarn workspace @hono/trpc-server build",
     "build": "run-p build:*"
   },
   "license": "MIT",

packages/trpc-server/README.md

@@ -0,0 +1,76 @@
+# tRPC Server Middleware for Hono
+
+tRPC Server Middleware adapts a [tRPC](https://trpc.io) server as middleware for Hono.
+Hono works on almost any JavaScript runtime, including Cloudflare Workers, Deno, and Bun. So, with this middleware, the same code will run as tRPC server.
+
+## Install
+
+```
+npm install @hono/trpc-server
+```
+
+## Usage
+
+Router:
+
+```ts
+import { initTRPC } from '@trpc/server'
+import { z } from 'zod'
+
+const t = initTRPC.create()
+
+const publicProcedure = t.procedure
+const router = t.router
+
+export const appRouter = router({
+  hello: publicProcedure.input(z.string().nullish()).query(({ input }) => {
+    return `Hello ${input ?? 'World'}!`
+  }),
+})
+
+export type AppRouter = typeof appRouter
+```
+
+Hono app using tRPC Server Middleware:
+
+```ts
+import { Hono } from 'hono'
+import { trpcServer } from '@hono/trpc-server' // Deno 'npm:@hono/trpc-server'
+import { appRouter } from './router'
+
+const app = new Hono()
+
+app.use(
+  '/trpc/*',
+  trpcServer({
+    router: appRouter,
+  })
+)
+
+export default app
+```
+
+Client:
+
+```ts
+import { createTRPCProxyClient, httpBatchLink } from '@trpc/client'
+import type { AppRouter } from './router'
+
+const client = createTRPCProxyClient<AppRouter>({
+  links: [
+    httpBatchLink({
+      url: 'http://localhost:8787/trpc',
+    }),
+  ],
+})
+
+console.log(await client.hello.query('Hono'))
+```
+
+## Author
+
+Yusuke Wada <https://github.com/yusukebe>
+
+## License
+
+MIT

packages/trpc-server/package.json

@@ -0,0 +1,42 @@
+{
+  "name": "@hono/trpc-server",
+  "version": "0.0.0",
+  "description": "tRPC Server Middleware for Hono",
+  "main": "dist/cjs/index.js",
+  "module": "dist/esm/index.js",
+  "types": "dist/esm/index.d.ts",
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "test": "jest",
+    "build:cjs": "tsc -p tsconfig.cjs.json",
+    "build:esm": "tsc -p tsconfig.esm.json",
+    "build": "rimraf dist && yarn build:cjs && yarn build:esm",
+    "prerelease": "yarn build && yarn test",
+    "release": "yarn publish"
+  },
+  "license": "MIT",
+  "private": false,
+  "publishConfig": {
+    "registry": "https://registry.npmjs.org",
+    "access": "public"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/honojs/middleware.git"
+  },
+  "homepage": "https://honojs.dev",
+  "peerDependencies": {
+    "@trpc/server": "^10.10.0",
+    "hono": "^2.7.5"
+  },
+  "devDependencies": {
+    "@trpc/server": "^10.10.0",
+    "hono": "^2.7.5",
+    "zod": "^3.20.2"
+  },
+  "engines": {
+    "node": ">=16.0.0"
+  }
+}

packages/trpc-server/src/index.ts

@@ -0,0 +1,19 @@
+import type { AnyRouter } from '@trpc/server'
+import { fetchRequestHandler } from '@trpc/server/adapters/fetch'
+import type { MiddlewareHandler } from 'hono'
+
+type tRPCOptions = {
+  endpoint?: string
+  router: AnyRouter
+}
+
+export const trpcServer = ({ router, endpoint = '/trpc' }: tRPCOptions): MiddlewareHandler => {
+  return async (c) => {
+    const res = fetchRequestHandler({
+      endpoint: endpoint,
+      req: c.req,
+      router: router,
+    })
+    return res
+  }
+}

packages/trpc-server/test/index.test.ts

@@ -0,0 +1,43 @@
+import { initTRPC } from '@trpc/server'
+import { Hono } from 'hono'
+import { z } from 'zod'
+import { trpcServer } from '../src'
+
+describe('tRPC Adapter Middleware', () => {
+  const t = initTRPC.create()
+
+  const publicProcedure = t.procedure
+  const router = t.router
+
+  const appRouter = router({
+    hello: publicProcedure.input(z.string().nullish()).query(({ input }) => {
+      return `Hello ${input ?? 'World'}`
+    }),
+  })
+
+  const app = new Hono()
+
+  app.use(
+    '/trpc/*',
+    trpcServer({
+      router: appRouter,
+    })
+  )
+
+  it('Should return 200 response', async () => {
+    const searchParams = new URLSearchParams({
+      input: JSON.stringify({ '0': 'Hono' }),
+      batch: '1',
+    })
+    const req = new Request(`http://localhost/trpc/hello?${searchParams.toString()}`)
+    const res = await app.request(req)
+    expect(res.status).toBe(200)
+    expect(await res.json()).toEqual([
+      {
+        result: {
+          data: 'Hello Hono',
+        },
+      },
+    ])
+  })
+})

packages/trpc-server/tsconfig.cjs.json

@@ -0,0 +1,8 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "module": "CommonJS",
+    "declaration": false,
+    "outDir": "./dist/cjs"
+  }
+}

packages/trpc-server/tsconfig.esm.json

@@ -0,0 +1,8 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "module": "ESNext",
+    "declaration": true,
+    "outDir": "./dist/esm"
+  }
+}

packages/trpc-adapter/tsconfig.json → packages/trpc-server/tsconfig.json

@@ -2,7 +2,6 @@
   "extends": "../../tsconfig.json",
   "compilerOptions": {
     "rootDir": "./src",
-    "outDir": "./dist",
   },
   "include": [
     "src/**/*.ts"

yarn.lock

@@ -1511,6 +1511,11 @@
   resolved "https://registry.yarnpkg.com/@tootallnate/once/-/once-2.0.0.tgz#f544a148d3ab35801c1f633a7441fd87c2e484bf"
   integrity sha512-XCuKFP5PS55gnMVu3dty8KPatLqUoy/ZYzDzAGCQ8JNFCkLXzmI7vNHCR+XpbZaMWQK/vQubr7PkYq8g470J/A==
 
+"@trpc/server@^10.10.0":
+  version "10.10.0"
+  resolved "https://registry.yarnpkg.com/@trpc/server/-/server-10.10.0.tgz#0b494335140d4fd5e1452f7b57dcc9b8886720a4"
+  integrity sha512-tCTqcqBT+3nebYFTHtwM877qo5xQPtVlptxKdUzMVWleWT4lFTL4oddk45qVURToci2iMbVJjd4jQU9y9/XwlQ==
+
 "@types/acorn@^4.0.0":
   version "4.0.6"
   resolved "https://registry.yarnpkg.com/@types/acorn/-/acorn-4.0.6.tgz#d61ca5480300ac41a7d973dd5b84d0a591154a22"
@@ -5185,12 +5190,7 @@ hono@3.0.0-rc.9:
   resolved "https://registry.yarnpkg.com/hono/-/hono-3.0.0-rc.9.tgz#6077bc67fce850dca99cd58452bda21ff8984da8"
   integrity sha512-gW/I51Uay6RhrDhtRN/3WTg7ALT3VRdk0NZBdGpkEOgF+TrzFwmWHDbzHUPa9MffiXSlrkFtMmJVvdKO3Iab8Q==
 
-hono@^2.3.0:
-  version "2.6.2"
-  resolved "https://registry.yarnpkg.com/hono/-/hono-2.6.2.tgz#1e32a4b4b3bf557a8aa87e392b00b505a1ec1fdd"
-  integrity sha512-Y4Uv6dPPx6u7TNoWN245tLw8jycBf97w0FJGJoEMdgdBqQEv1dqIvg5IfDhiYMkimSIt4SXxmMgiyPf2wzwFWQ==
-
-hono@^2.6.1:
+hono@^2.6.1, hono@^2.7.5:
   version "2.7.5"
   resolved "https://registry.yarnpkg.com/hono/-/hono-2.7.5.tgz#2b0c39d39a057575962a7025373be4304dedca9c"
   integrity sha512-UYrhUT1Xtalh7Xw/YGXee25wlWMiVIRfr0FbAJMEMyRpX9TFZ/6JKmVdCK7ioRnhAw7PfWBasjSBhdNXQ8/okQ==
@@ -10806,6 +10806,11 @@ zod@3.19.1:
   resolved "https://registry.yarnpkg.com/zod/-/zod-3.19.1.tgz#112f074a97b50bfc4772d4ad1576814bd8ac4473"
   integrity sha512-LYjZsEDhCdYET9ikFu6dVPGp2YH9DegXjdJToSzD9rO6fy4qiRYFoyEYwps88OseJlPyl2NOe2iJuhEhL7IpEA==
 
+zod@^3.20.2:
+  version "3.20.2"
+  resolved "https://registry.yarnpkg.com/zod/-/zod-3.20.2.tgz#068606642c8f51b3333981f91c0a8ab37dfc2807"
+  integrity sha512-1MzNQdAvO+54H+EaK5YpyEy0T+Ejo/7YLHS93G3RnYWh5gaotGHwGeN/ZO687qEDU2y4CdStQYXVHIgrUl5UVQ==
+
 zwitch@^2.0.0:
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/zwitch/-/zwitch-2.0.4.tgz#c827d4b0acb76fc3e685a4c6ec2902d51070e9d7"