feat: parse json body correctlly

Signed-off-by: seven <[email protected]>

Author: Blankll

package-lock.json

@@ -53,14 +53,15 @@
   "devDependencies": {
     "@eslint/js": "^9.12.0",
     "@types/express": "^5.0.0",
-    "express": "^4.21.0",
     "@types/jest": "^29.5.13",
     "@types/node": "^22.7.4",
     "@typescript-eslint/eslint-plugin": "^8.8.0",
     "@typescript-eslint/parser": "^8.8.0",
     "eslint": "^8.57.1",
     "eslint-config-prettier": "^9.1.0",
     "eslint-plugin-prettier": "^5.2.1",
+    "express": "^4.21.0",
+    "body-parser": "^1.20.3",
     "globals": "^15.10.0",
     "husky": "^9.1.6",
     "jest": "^29.7.0",

package.json

@@ -11,7 +11,7 @@ const constructFrameworkContext = (event: Event, context: Context) => {
   const request = new ServerlessRequest({
     method: event.httpMethod,
     headers: event.headers,
-    body: event.body,
+    body: Buffer.from(event.body, event.isBase64Encoded ? 'base64' : 'utf8'),
     remoteAddress: '',
     url: event.path,
     isBase64Encoded: event.isBase64Encoded,

src/index.ts

@@ -8,7 +8,7 @@ const HTTPS_PORT = 443;
 interface ServerlessRequestOptions {
   method: string;
   url: string;
-  headers: { [key: string]: string };
+  headers: { [key: string]: string | number };
   body: Buffer | string;
   remoteAddress: string;
   isBase64Encoded: boolean;
@@ -47,18 +47,12 @@ export default class ServerlessRequest extends IncomingMessage {
       destroy: NO_OP,
     } as unknown as Socket);
 
-    // IncomingMessage has a lot of logic for when to lowercase or alias well-known header names,
-    // so we delegate to that logic here
-    const headerEntries = Object.entries(headers);
-    const rawHeaders = new Array(headerEntries.length * 2);
-    for (let i = 0; i < headerEntries.length; i++) {
-      rawHeaders[i * 2] = headerEntries[i][0];
-      rawHeaders[i * 2 + 1] = headerEntries[i][1];
-    }
-
-    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-    // @ts-expect-error
-    this._addHeaderLines(rawHeaders, rawHeaders.length);
+    const combinedHeaders = Object.fromEntries(
+      Object.entries({
+        ...headers,
+        'content-length': Buffer.byteLength(body).toString(),
+      }).map(([key, value]) => [key.toLowerCase(), value]),
+    );
 
     Object.assign(this, {
       ip: remoteAddress,
@@ -69,6 +63,7 @@ export default class ServerlessRequest extends IncomingMessage {
       method,
       body,
       url,
+      headers: combinedHeaders,
       isBase64Encoded,
     });