feat: setup test for koa application

package.json

@@ -51,9 +51,13 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.12.0",
+    "@koa/router": "^13.1.0",
     "@types/debug": "^4.1.12",
     "@types/express": "^5.0.0",
     "@types/jest": "^29.5.13",
+    "@types/koa": "^2.15.0",
+    "@types/koa-static": "^4.0.4",
+    "@types/koa__router": "^12.0.4",
     "@types/node": "^22.7.4",
     "@typescript-eslint/eslint-plugin": "^8.8.0",
     "@typescript-eslint/parser": "^8.8.0",
@@ -65,6 +69,9 @@
     "globals": "^15.10.0",
     "husky": "^9.1.6",
     "jest": "^29.7.0",
+    "koa": "^2.15.3",
+    "koa-body": "^6.0.1",
+    "koa-static": "^5.0.0",
     "prettier": "^3.3.3",
     "ts-jest": "^29.2.5",
     "ts-node": "^10.9.2",

src/context.ts

@@ -1,7 +1,6 @@
 import { Context, Event } from './types';
 import ServerlessRequest from './serverlessRequest';
 import url from 'node:url';
-import ServerlessResponse from './serverlessResponse';
 import { debug } from './common';
 
 // const requestRemoteAddress = (event) => {
@@ -11,23 +10,56 @@
 //   return event.requestContext.identity.sourceIp;
 // };
 
+const requestBody = (event: Event) => {
+  if (event.body === undefined || event.body === null) {
+    return undefined;
+  }
+  const type = typeof event.body;
+
+  if (Buffer.isBuffer(event.body)) {
+    return event.body;
+  } else if (type === 'string') {
+    return Buffer.from(event.body as string, event.isBase64Encoded ? 'base64' : 'utf8');
+  } else if (type === 'object') {
+    return Buffer.from(JSON.stringify(event.body));
+  }
+
+  throw new Error(`Unexpected event.body type: ${typeof event.body}`);
+};
+
+const requestHeaders = (event: Event) => {
+  const initialHeader = {} as Record<string, string>;
+
+  // if (event.multiValueHeaders) {
+  //   Object.keys(event.multiValueHeaders).reduce((headers, key) => {
+  //     headers[key.toLowerCase()] = event.multiValueHeaders[key].join(', ');
+  //     return headers;
+  //   }, initialHeader);
+  // }
+
+  return Object.keys(event.headers).reduce((headers, key) => {
+    headers[key.toLowerCase()] = event.headers[key];
+    return headers;
+  }, initialHeader);
+};
+
 export const constructFrameworkContext = (event: Event, context: Context) => {
   debug(`constructFrameworkContext: ${JSON.stringify({ event, context })}`);
+  const body = requestBody(event);
+  const headers = requestHeaders(event);
+
   const request = new ServerlessRequest({
     method: event.httpMethod,
-    headers: event.headers,
-    body:
-      event.body !== undefined && event.body !== null
-        ? Buffer.from(event.body, event.isBase64Encoded ? 'base64' : 'utf8')
-        : undefined,
+    path: event.path,
+    headers,
+    body,
     remoteAddress: '',
     url: url.format({
       pathname: event.path,
       query: event.queryParameters,
     }),
     isBase64Encoded: event.isBase64Encoded,
   });
-  const response = new ServerlessResponse(request);
 
-  return { request, response };
+  return { request };
 };

src/framework.ts

@@ -0,0 +1,25 @@
+import { Express } from 'express';
+import Application from 'koa';
+import ServerlessResponse from './serverlessResponse';
+import ServerlessRequest from './serverlessRequest';
+
+// eslint-disable-next-line
+const callableFn = (callback: (req: any, res: any) => Promise<void>) => {
+  return async (request: ServerlessRequest) => {
+    const response = new ServerlessResponse(request);
+
+    callback(request, response);
+
+    return response;
+  };
+};
+
+export const constructFramework = (app: Express | Application) => {
+  if (app instanceof Application) {
+    return callableFn(app.callback());
+  } else if (typeof app === 'function') {
+    return callableFn(app);
+  } else {
+    throw new Error(`Unsupported framework ${app}`);
+  }
+};

src/index.ts

@@ -1,18 +1,18 @@
 import { Express } from 'express';
+import Application from 'koa';
 import { ServerlessAdapter } from './types';
-import sendRequest from './sendRequest';
 import { IncomingHttpHeaders } from 'http';
 import { constructFrameworkContext } from './context';
 import { buildResponse, waitForStreamComplete } from './transport';
+import { constructFramework } from './framework';
 
-const serverlessAdapter: ServerlessAdapter = (app: Express) => {
+const serverlessAdapter: ServerlessAdapter = (app: Express | Application) => {
+  const serverlessFramework = constructFramework(app);
   return async (event, context) => {
-    const { request, response } = constructFrameworkContext(event, context);
+    const { request } = constructFrameworkContext(event, context);
 
     try {
-      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-      // @ts-expect-error
-      await sendRequest(app, request, response);
+      const response = await serverlessFramework(request);
       await waitForStreamComplete(response);
       return buildResponse({ request, response });
     } catch (err) {

src/serverlessRequest.ts

@@ -6,6 +6,7 @@ const HTTPS_PORT = 443;
 interface ServerlessRequestOptions {
   method: string;
   url: string;
+  path: string;
   headers: { [key: string]: string | number };
   body: Buffer | string | undefined;
   remoteAddress: string;
@@ -21,46 +22,40 @@ export default class ServerlessRequest extends IncomingMessage {
 
   isBase64Encoded: boolean;
 
-  constructor({
-    method,
-    url,
-    headers,
-    body,
-    remoteAddress,
-    isBase64Encoded,
-  }: ServerlessRequestOptions) {
+  constructor(request: ServerlessRequestOptions) {
     super({
       encrypted: true,
       readable: false,
-      remoteAddress,
+      remoteAddress: request.remoteAddress,
       address: () => ({ port: HTTPS_PORT }),
       end: NO_OP,
       destroy: NO_OP,
+      path: request.path,
+      headers: request.headers,
     } as unknown as Socket);
 
     const combinedHeaders = Object.fromEntries(
       Object.entries({
-        ...headers,
-        'content-length': Buffer.byteLength(body ?? '').toString(),
+        ...request.headers,
+        'content-length': Buffer.byteLength(request.body ?? '').toString(),
       }).map(([key, value]) => [key.toLowerCase(), value]),
     );
 
     Object.assign(this, {
+      ...request,
       complete: true,
       httpVersion: '1.1',
       httpVersionMajor: '1',
       httpVersionMinor: '1',
-      method,
-      url,
       headers: combinedHeaders,
     });
 
-    this.body = body;
-    this.ip = remoteAddress;
-    this.isBase64Encoded = isBase64Encoded;
+    this.body = request.body;
+    this.ip = request.remoteAddress;
+    this.isBase64Encoded = request.isBase64Encoded;
 
     this._read = () => {
-      this.push(body);
+      this.push(request.body);
       this.push(null);
     };
   }

src/serverlessResponse.ts

@@ -1,8 +1,7 @@
 import { IncomingHttpHeaders, ServerResponse } from 'http';
-import { IncomingMessage } from 'node:http';
-import ServerlessRequest from './serverlessRequest';
 import { Socket } from 'node:net';
 import { debug } from './common';
+import ServerlessRequest from './serverlessRequest';
 
 const headerEnd = '\r\n\r\n';
 
@@ -37,12 +36,8 @@ export default class ServerlessResponse extends ServerResponse {
   [BODY]: Buffer[];
   [HEADERS]: IncomingHttpHeaders;
 
-  static from(res: IncomingMessage): ServerlessResponse {
-    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-    // @ts-expect-error
+  static from(res: ServerlessRequest): ServerlessResponse {
     const response = new ServerlessResponse(res);
-    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-    // @ts-expect-error
     const { statusCode = 0, headers, body } = res;
     response.statusCode = statusCode;
     response[HEADERS] = headers;

src/transport.ts

@@ -1,17 +1,17 @@
 import { Writable } from 'stream';
+import { IncomingHttpHeaders } from 'http';
 import ServerlessRequest from './serverlessRequest';
 import ServerlessResponse from './serverlessResponse';
 
+type MultiValueHeaders = {
+  [key: string]: string[];
+};
 export const waitForStreamComplete = (stream: Writable): Promise<Writable> => {
   if (stream.writableFinished || stream.writableEnded) {
     return Promise.resolve(stream);
   }
 
   return new Promise((resolve, reject) => {
-    stream.once('error', complete);
-    stream.once('end', complete);
-    stream.once('finish', complete);
-
     let isComplete = false;
 
     function complete(err?: Error) {
@@ -31,20 +31,65 @@
         resolve(stream);
       }
     }
+
+    stream.once('error', complete);
+    stream.once('end', complete);
+    stream.once('finish', complete);
   });
 };
 
+const sanitizeHeaders = (headers: IncomingHttpHeaders) => {
+  return Object.keys(headers).reduce(
+    (memo, key) => {
+      const value = headers[key];
+
+      if (Array.isArray(value)) {
+        memo.multiValueHeaders[key] = value;
+        if (key.toLowerCase() !== 'set-cookie') {
+          memo.headers[key] = value.join(', ');
+        }
+      } else {
+        memo.headers[key] = value == null ? '' : value.toString();
+      }
+
+      return memo;
+    },
+    {
+      headers: {} as IncomingHttpHeaders,
+      multiValueHeaders: {} as MultiValueHeaders,
+    },
+  );
+};
+
 export const buildResponse = ({
   request,
   response,
 }: {
   request: ServerlessRequest;
   response: ServerlessResponse;
 }) => {
+  const { headers, multiValueHeaders } = sanitizeHeaders(ServerlessResponse.headers(response));
+
+  let body = ServerlessResponse.body(response).toString(
+    request.isBase64Encoded ? 'base64' : 'utf8',
+  );
+  if (headers['transfer-encoding'] === 'chunked' || response.chunkedEncoding) {
+    const raw = ServerlessResponse.body(response).toString().split('\r\n');
+    const parsed = [];
+    for (let i = 0; i < raw.length; i += 2) {
+      const size = parseInt(raw[i], 16);
+      const value = raw[i + 1];
+      if (value) {
+        parsed.push(value.substring(0, size));
+      }
+    }
+    body = parsed.join('');
+  }
   return {
     statusCode: response.statusCode,
-    body: ServerlessResponse.body(response).toString(request.isBase64Encoded ? 'base64' : 'utf8'),
-    headers: response.headers,
+    body,
+    headers,
+    multiValueHeaders,
     isBase64Encoded: request.isBase64Encoded,
   };
 };

src/types.ts

@@ -1,4 +1,5 @@
 import { Express } from 'express';
+import Application from 'koa';
 import { IncomingHttpHeaders } from 'http';
 
 type AliyunApiGatewayEvent = {
@@ -52,7 +53,7 @@ type AliyunApiGatewayContext = {
 export type Event = AliyunApiGatewayEvent;
 export type Context = AliyunApiGatewayContext;
 
-export type ServerlessAdapter = (app: Express) => (
+export type ServerlessAdapter = (app: Express | Application) => (
   event: Event,
   context: Context,
 ) => Promise<{