feat: implement azure-functions adapter

src/adapter/azure-functions/handler.ts

@@ -0,0 +1,59 @@
+import type {
+  Context as AzureFunctionsContext,
+  HttpRequest as AzureFunctionsHttpRequest,
+} from '@azure/functions'
+import type { Hono } from '../../hono'
+
+export interface AzureFunctionsHTTPEvent {
+  context: AzureFunctionsContext
+  req: AzureFunctionsHttpRequest
+}
+
+export const handle = (app: Hono) => {
+  return async (event: AzureFunctionsHTTPEvent): Promise<AzureFunctionsContext> => {
+    const req = createRequest(event)
+    const res = await app.fetch(req)
+
+    return createResult(event.context, res)
+  }
+}
+
+const createRequest = (event: AzureFunctionsHTTPEvent): Request => {
+  const urlPath = event.req.url
+  const url = urlPath
+
+  const headersKV = {}
+  for (const [k, v] of Object.entries(event.req.headers)) {
+    if (v) headersKV[k] = v
+  }
+
+  const headers = new Headers(headersKV)
+
+  const method = event.req.method
+  const requestInit: RequestInit = {
+    headers,
+    method,
+  }
+
+  if (event.req.body) {
+    requestInit.body = JSON.stringify(event.req.body)
+  }
+
+  return new Request(url, requestInit)
+}
+
+const createResult = async (
+  context: AzureFunctionsContext,
+  res: Response
+): Promise<AzureFunctionsContext> => {
+  const contentType = res.headers.get('content-type')
+
+  res.headers.forEach((value, key) => {
+    context.res.headers[key] = value
+  })
+
+  context.res.headers['Content-Type'] = contentType ?? 'text/plain'
+  context.res.body = await res.text()
+
+  return context
+}

src/adapter/azure-functions/index.ts

@@ -0,0 +1 @@
+export { handle } from './handler'