feat: Add Effect Schema validator (#589)

* First commit

* Add basic Effect Schema validator

* chore(effect-validator): Change name of middleware to `effect-validator` and fix devDependencies

* chores(effect-validator): Update yarn.lock

* Remove bun lock file

* chores(effect-validator): Add github workflow

* chores: Update yarn.lock

* refactor the code and correct settings

* remove unnecessary files

---------

Co-authored-by: Yusuke Wada <[email protected]>

.changeset/poor-clouds-fix.md

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+---
+'@hono/schema-validator': major
+---
+
+Add new basic Effect Schema validator middleware

.github/workflows/ci-effect-validator.yml

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+name: ci-effect-validator
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'packages/effect-validator/**'
+  pull_request:
+    branches: ['*']
+    paths:
+      - 'packages/effect-validator/**'
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./packages/effect-validator
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20.x
+      - run: yarn install --frozen-lockfile
+      - run: yarn build
+      - run: yarn test

packages/effect-validator/README.md

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+# Effect Schema Validator Middleware for Hono
+
+This package provides a validator middleware using [Effect Schema](https://github.com/Effect-TS/effect/blob/main/packages/schema/README.md) for [Hono](https://honojs.dev) applications. With this middleware, you can define schemas using Effect Schema and validate incoming data in your Hono routes.
+
+## Why Effect Schema?
+
+Effect Schema offers several advantages over other validation libraries:
+
+1. Bidirectional transformations: Effect Schema can both decode and encode data.
+2. Integration with Effect: It inherits benefits from the Effect ecosystem, such as dependency tracking in transformations.
+3. Highly customizable: Users can attach meta-information through annotations.
+4. Functional programming style: Uses combinators and transformations for schema definition.
+
+## Usage
+
+```ts
+import { Hono } from 'hono'
+import { Schema as S } from '@effect/schema'
+import { effectValidator } from '@hono/effect-validator'
+
+const app = new Hono()
+
+const User = S.Struct({
+  name: S.String,
+  age: S.Number,
+})
+
+app.post('/user', effectValidator('json', User), (c) => {
+  const user = c.req.valid('json')
+
+  return c.json({
+    success: true,
+    message: `${user.name} is ${user.age}`,
+  })
+})
+```
+
+## API
+
+### `effectValidator(target, schema)`
+
+- `target`: The target of validation ('json', 'form', 'query', etc.)
+- `schema`: An Effect Schema schema
+
+## Author
+
+Günther Brunner <https://github.com/gunta>
+
+## License
+
+MIT

packages/effect-validator/package.json

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+{
+  "name": "@hono/effect-validator",
+  "version": "0.0.0",
+  "description": "Validator middleware using Effect Schema",
+  "type": "module",
+  "main": "dist/cjs/index.js",
+  "module": "dist/esm/index.js",
+  "types": "dist/esm/index.d.ts",
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist/index.d.ts",
+        "default": "./dist/index.js"
+      },
+      "require": {
+        "types": "./dist/index.d.cts",
+        "default": "./dist/index.cjs"
+      }
+    }
+  },
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "test": "vitest --run",
+    "build": "tsup ./src/index.ts --format esm,cjs --dts",
+    "publint": "publint",
+    "release": "yarn build && yarn test && yarn publint && yarn publish"
+  },
+  "license": "MIT",
+  "publishConfig": {
+    "registry": "https://registry.npmjs.org",
+    "access": "public"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/honojs/middleware.git"
+  },
+  "homepage": "https://github.com/honojs/middleware",
+  "peerDependencies": {
+    "@effect/schema": ">=0.68.18",
+    "hono": ">=4.4.13"
+  },
+  "devDependencies": {
+    "@effect/schema": "^0.68.21",
+    "effect": "^3.4.8",
+    "hono": "^4.4.13",
+    "tsup": "^8.1.0",
+    "typescript": "^5.5.3",
+    "vitest": "^2.0.1"
+  }
+}

packages/effect-validator/src/index.ts

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+import * as S from '@effect/schema/Schema'
+import { Either } from 'effect'
+import type { Env, Input, MiddlewareHandler, ValidationTargets } from 'hono'
+import type { Simplify } from 'hono/utils/types'
+import { validator } from 'hono/validator'
+
+type RemoveReadonly<T> = { -readonly [P in keyof T]: RemoveReadonly<T[P]> }
+
+type HasUndefined<T> = undefined extends T ? true : false
+
+export const effectValidator = <
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  T extends S.Schema.Variance<any, any, any>,
+  Target extends keyof ValidationTargets,
+  E extends Env,
+  P extends string,
+  In = Simplify<RemoveReadonly<S.Schema.Type<T>>>,
+  Out = Simplify<RemoveReadonly<S.Schema.Type<T>>>,
+  I extends Input = {
+    in: HasUndefined<In> extends true
+      ? {
+          [K in Target]?: K extends 'json'
+            ? In
+            : HasUndefined<keyof ValidationTargets[K]> extends true
+            ? { [K2 in keyof In]?: ValidationTargets[K][K2] }
+            : { [K2 in keyof In]: ValidationTargets[K][K2] }
+        }
+      : {
+          [K in Target]: K extends 'json'
+            ? In
+            : HasUndefined<keyof ValidationTargets[K]> extends true
+            ? { [K2 in keyof In]?: ValidationTargets[K][K2] }
+            : { [K2 in keyof In]: ValidationTargets[K][K2] }
+        }
+    out: { [K in Target]: Out }
+  },
+  V extends I = I
+>(
+  target: Target,
+  schema: T
+): MiddlewareHandler<E, P, V> =>
+  // @ts-expect-error not typed well
+  validator(target, async (value, c) => {
+    // @ts-expect-error not typed well
+    const result = S.decodeUnknownEither(schema)(value)
+
+    return Either.match(result, {
+      onLeft: (error) => c.json({ success: false, error: JSON.parse(JSON.stringify(error)) }, 400),
+      onRight: (data) => {
+        c.req.addValidatedData(target, data as object)
+        return data
+      },
+    })
+  })

packages/effect-validator/test/index.test.ts

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+import { Schema as S } from '@effect/schema'
+import { Hono } from 'hono'
+import type { StatusCode } from 'hono/utils/http-status'
+import type { Equal, Expect } from 'hono/utils/types'
+import { effectValidator } from '../src'
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+type ExtractSchema<T> = T extends Hono<infer _, infer S> ? S : never
+
+describe('Basic', () => {
+  const app = new Hono()
+
+  const jsonSchema = S.Struct({
+    name: S.String,
+    age: S.Number,
+  })
+
+  const querySchema = S.Union(
+    S.Struct({
+      name: S.optional(S.String),
+    }),
+    S.Undefined
+  )
+
+  const route = app.post(
+    '/author',
+    effectValidator('json', jsonSchema),
+    effectValidator('query', querySchema),
+    (c) => {
+      const data = c.req.valid('json')
+      const query = c.req.valid('query')
+
+      return c.json({
+        success: true,
+        message: `${data.name} is ${data.age}`,
+        queryName: query?.name,
+      })
+    }
+  )
+
+  type Actual = ExtractSchema<typeof route>
+
+  type Expected = {
+    '/author': {
+      $post: {
+        input: {
+          json: {
+            name: string
+            age: number
+          }
+        } & {
+          query?: {
+            name?: string | string[] | undefined
+          }
+        }
+        output: {
+          success: boolean
+          message: string
+          queryName: string | undefined
+        }
+        outputFormat: 'json'
+        status: StatusCode
+      }
+    }
+  }
+
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  type verify = Expect<Equal<Expected, Actual>>
+
+  it('Should return 200 response', async () => {
+    const req = new Request('http://localhost/author?name=Metallo', {
+      body: JSON.stringify({
+        name: 'Superman',
+        age: 20,
+      }),
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    })
+    const res = await app.request(req)
+    expect(res).not.toBeNull()
+    expect(res.status).toBe(200)
+    expect(await res.json()).toEqual({
+      success: true,
+      message: 'Superman is 20',
+      queryName: 'Metallo',
+    })
+  })
+
+  it('Should return 400 response', async () => {
+    const req = new Request('http://localhost/author', {
+      body: JSON.stringify({
+        name: 'Superman',
+        age: '20',
+      }),
+      method: 'POST',
+      headers: {
+        'content-type': 'application/json',
+      },
+    })
+    const res = await app.request(req)
+    expect(res).not.toBeNull()
+    expect(res.status).toBe(400)
+
+    const data = (await res.json()) as { success: boolean }
+    expect(data.success).toBe(false)
+  })
+})
+
+describe('coerce', () => {
+  const app = new Hono()
+
+  const querySchema = S.Struct({
+    page: S.NumberFromString,
+  })
+
+  const route = app.get('/page', effectValidator('query', querySchema), (c) => {
+    const { page } = c.req.valid('query')
+    return c.json({ page })
+  })
+
+  type Actual = ExtractSchema<typeof route>
+  type Expected = {
+    '/page': {
+      $get: {
+        input: {
+          query: {
+            page: string | string[]
+          }
+        }
+        output: {
+          page: number
+        }
+        outputFormat: 'json'
+        status: StatusCode
+      }
+    }
+  }
+
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  type verify = Expect<Equal<Expected, Actual>>
+
+  it('Should return 200 response', async () => {
+    const res = await app.request('/page?page=123')
+    expect(res).not.toBeNull()
+    expect(res.status).toBe(200)
+    expect(await res.json()).toEqual({
+      page: 123,
+    })
+  })
+})

packages/effect-validator/tsconfig.json

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+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "./src",
+    "exactOptionalPropertyTypes": true
+  },
+  "include": [
+    "src/**/*.ts"
+  ],
+}

packages/effect-validator/vitest.config.ts

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+/// <reference types="vitest" />
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    globals: true,
+  },
+})