feat(cloudflare-pages): Add Cloudflare Pages middleware handler (#3028)

* Add Cloudflare Pages middleware handler

* fix: handle HTTPException

* fix: handle context.error

* fix: remove HonoRequest from conninfo test

src/adapter/cloudflare-pages/handler.test.ts

@@ -1,6 +1,8 @@
+import { getCookie } from '../../helper/cookie'
 import { Hono } from '../../hono'
+import { HTTPException } from '../../http-exception'
 import type { EventContext } from './handler'
-import { handle } from './handler'
+import { handle, handleMiddleware } from './handler'
 
 type Env = {
   Bindings: {
@@ -49,3 +51,193 @@ describe('Adapter for Cloudflare Pages', () => {
     expect(() => handler({ request })).toThrowError('Custom Error')
   })
 })
+
+describe('Middleware adapter for Cloudflare Pages', () => {
+  it('Should return the middleware response', async () => {
+    const request = new Request('http://localhost/api/foo', {
+      headers: {
+        Cookie: 'my_cookie=1234',
+      },
+    })
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware(async (c, next) => {
+      const cookie = getCookie(c, 'my_cookie')
+
+      await next()
+
+      return c.json({ cookie, response: await c.res.json() })
+    })
+
+    const next = vi.fn().mockResolvedValue(Response.json('From Cloudflare Pages'))
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    const res = await handler({ request, env, next })
+
+    expect(next).toHaveBeenCalled()
+
+    expect(await res.json()).toEqual({
+      cookie: '1234',
+      response: 'From Cloudflare Pages',
+    })
+  })
+
+  it('Should return the middleware response when exceptions are handled', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware(async (c, next) => {
+      await next()
+
+      return c.json({ error: c.error?.message })
+    })
+
+    const next = vi.fn().mockRejectedValue(new Error('Error from next()'))
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    const res = await handler({ request, env, next })
+
+    expect(next).toHaveBeenCalled()
+
+    expect(await res.json()).toEqual({
+      error: 'Error from next()',
+    })
+  })
+
+  it('Should return the middleware response if next() is not called', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware(async (c) => {
+      return c.json({ response: 'Skip Cloudflare Pages' })
+    })
+
+    const next = vi.fn()
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    const res = await handler({ request, env, next })
+
+    expect(next).not.toHaveBeenCalled()
+
+    expect(await res.json()).toEqual({
+      response: 'Skip Cloudflare Pages',
+    })
+  })
+
+  it('Should return the Pages response if the middleware does not return a response', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware((c, next) => next())
+
+    const next = vi.fn().mockResolvedValue(Response.json('From Cloudflare Pages'))
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    const res = await handler({ request, env, next })
+
+    expect(next).toHaveBeenCalled()
+
+    expect(await res.json()).toEqual('From Cloudflare Pages')
+  })
+
+  it('Should handle a HTTPException by returning error.getResponse()', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware(() => {
+      const res = new Response('Unauthorized', { status: 401 })
+      throw new HTTPException(401, { res })
+    })
+
+    const next = vi.fn()
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    const res = await handler({ request, env, next })
+
+    expect(next).not.toHaveBeenCalled()
+
+    expect(res.status).toBe(401)
+    expect(await res.text()).toBe('Unauthorized')
+  })
+
+  it('Should handle an HTTPException thrown by next()', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware((c, next) => next())
+
+    const next = vi
+      .fn()
+      .mockRejectedValue(new HTTPException(401, { res: Response.json('Unauthorized') }))
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    const res = await handler({ request, env, next })
+
+    expect(next).toHaveBeenCalled()
+
+    expect(await res.json()).toEqual('Unauthorized')
+  })
+
+  it('Should handle an Error thrown by next()', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware((c, next) => next())
+
+    const next = vi.fn().mockRejectedValue(new Error('Error from next()'))
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    await expect(handler({ request, env, next })).rejects.toThrowError('Error from next()')
+    expect(next).toHaveBeenCalled()
+  })
+
+  it('Should handle a non-Error thrown by next()', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware((c, next) => next())
+
+    const next = vi.fn().mockRejectedValue('Error from next()')
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    await expect(handler({ request, env, next })).rejects.toThrowError('Error from next()')
+    expect(next).toHaveBeenCalled()
+  })
+
+  it('Should rethrow an Error', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware(() => {
+      throw new Error('Something went wrong')
+    })
+
+    const next = vi.fn()
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    await expect(handler({ request, env, next })).rejects.toThrowError('Something went wrong')
+    expect(next).not.toHaveBeenCalled()
+  })
+
+  it('Should rethrow non-Error exceptions', async () => {
+    const request = new Request('http://localhost/api/foo')
+    const env = {
+      TOKEN: 'HONOISCOOL',
+    }
+    const handler = handleMiddleware(() => Promise.reject('Something went wrong'))
+    const next = vi.fn()
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    await expect(handler({ request, env, next })).rejects.toThrowError('Something went wrong')
+    expect(next).not.toHaveBeenCalled()
+  })
+})

src/adapter/cloudflare-pages/handler.ts

@@ -1,5 +1,7 @@
+import { Context } from '../../context'
 import type { Hono } from '../../hono'
-import type { MiddlewareHandler } from '../../types'
+import { HTTPException } from '../../http-exception'
+import type { Env, Input, MiddlewareHandler } from '../../types'
 
 // Ref: https://github.com/cloudflare/workerd/blob/main/types/defines/pages.d.ts
 
@@ -18,6 +20,13 @@ export type EventContext<Env = {}, P extends string = any, Data = {}> = {
   data: Data
 }
 
+declare type PagesFunction<
+  Env = unknown,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  Params extends string = any,
+  Data extends Record<string, unknown> = Record<string, unknown>
+> = (context: EventContext<Env, Params, Data>) => Response | Promise<Response>
+
 interface HandleInterface {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   (app: Hono<any, any, any>): (eventContext: EventContext) => Response | Promise<Response>
@@ -34,6 +43,54 @@ export const handle: HandleInterface = (app: Hono) => (eventContext: EventContex
   )
 }
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export function handleMiddleware<E extends Env = any, P extends string = any, I extends Input = {}>(
+  middleware: MiddlewareHandler<E, P, I>
+): PagesFunction {
+  return async (executionCtx) => {
+    const context = new Context(executionCtx.request, {
+      env: executionCtx.env,
+      executionCtx,
+    })
+
+    let response: Response | void = undefined
+
+    try {
+      response = await middleware(context, async () => {
+        try {
+          context.res = await executionCtx.next()
+        } catch (error) {
+          if (error instanceof Error) {
+            context.error = error
+          } else {
+            throw error
+          }
+        }
+      })
+    } catch (error) {
+      if (error instanceof Error) {
+        context.error = error
+      } else {
+        throw error
+      }
+    }
+
+    if (response) {
+      return response
+    }
+
+    if (context.error instanceof HTTPException) {
+      return context.error.getResponse()
+    }
+
+    if (context.error) {
+      throw context.error
+    }
+
+    return context.res
+  }
+}
+
 declare abstract class FetcherLike {
   fetch(input: RequestInfo, init?: RequestInit): Promise<Response>
 }

src/adapter/cloudflare-pages/index.ts

@@ -3,5 +3,5 @@
  * Cloudflare Pages Adapter for Hono.
  */
 
-export { handle, serveStatic } from './handler'
+export { handle, handleMiddleware, serveStatic } from './handler'
 export type { EventContext } from './handler'