feat: allow capturing logs

src/request.ts

@@ -1,6 +1,7 @@
 import { Socket } from "node:net";
 import http from "node:http";
 import { Readable } from "node:stream";
+import { Logger } from "./utils/logger";
 
 export interface RequestEvent {
   url: string; // /relative/path?query=value#hash
@@ -10,14 +11,12 @@ export interface RequestEvent {
   headers: http.IncomingHttpHeaders;
   remoteAddress?: string;
   remotePort?: string;
-  context?: {
-    features?: Record<string, boolean>;
-    apiKey?: string;
-    envId?: string;
-  };
+  captureLogs?: boolean;
 }
 
 class Request extends http.IncomingMessage {
+  logger?: Logger;
+
   constructor(props: RequestEvent) {
     const socket = {
       readable: false,
@@ -31,6 +30,10 @@ class Request extends http.IncomingMessage {
 
     super(socket);
 
+    if (props.captureLogs) {
+      this.logger = new Logger();
+    }
+
     // Node.js < 13 support
     this.connection = socket;
 

src/response.ts

@@ -10,6 +10,7 @@ export interface ServerlessResponse {
   status?: number;
   statusMessage?: string;
   headers?: Record<string, string | string[]>;
+  logs?: string;
 }
 
 class Response extends ServerResponse {
@@ -42,6 +43,7 @@ class Response extends ServerResponse {
         headers: parsed.headers,
         statusMessage: parsed.statusMessage || "OK",
         status: parsed.statusCode || 200,
+        logs: req.logger?.logs(),
       });
     });
   }

src/utils/callbacks/api.spec.ts

@@ -12,12 +12,20 @@ jest.mock("~/utils/filesys", () => ({
 
 describe("utils/callback/api.ts", () => {
   describe("handleApi", () => {
+    const expectedLogs =
+      "this is an info\n" +
+      "this info log should be captured\n" +
+      "this is another info\n" +
+      "this error log should be captured\n" +
+      "this comes from process.stdout.write";
+
     const exampleRequest = {
       method: "GET",
       url: "/",
       path: "/",
       body: "",
       headers: {},
+      captureLogs: true,
     };
 
     afterEach(() => {
@@ -30,6 +38,12 @@ describe("utils/callback/api.ts", () => {
           "/path/to/api-file.ts",
           () => ({
             default: () => {
+              console.info("this is an info");
+              console.log("this info log should be captured");
+              console.info("this is another info");
+              console.error("this error log should be captured");
+              process.stdout.write("this comes from process.stdout.write");
+
               return {
                 body: "Hello world",
                 status: 201,
@@ -49,6 +63,7 @@ describe("utils/callback/api.ts", () => {
         expect(response).toEqual({
           body: "Hello world",
           status: 201,
+          logs: expectedLogs,
           headers: {
             "X-Custom-Header": "Sample Project",
           },
@@ -78,6 +93,7 @@ describe("utils/callback/api.ts", () => {
           buffer: "SGkgd29ybGQ=",
           status: 200,
           statusMessage: "OK",
+          logs: expectedLogs,
           headers: {
             connection: "close",
             date: expect.any(String),

src/utils/callbacks/api.ts

@@ -70,7 +70,7 @@ export const handleApi = (
         const ret = await invokeApiHandler(mod, req, res);
 
         if (ret) {
-          resolve(ret);
+          resolve({ ...ret, logs: req.logger?.logs() });
         }
 
         return;

src/utils/logger.ts

@@ -0,0 +1,38 @@
+import stream from "node:stream";
+
+const stdout: string[] = [];
+const originalConsole = console;
+const originalStdout = process.stdout.write;
+const originalStderr = process.stderr.write;
+
+class Stdout extends stream.Writable {
+  _write(
+    chunk: any,
+    _: BufferEncoding,
+    callback: (error?: Error | null) => void
+  ): void {
+    stdout.push(chunk.toString());
+    callback(null);
+  }
+}
+
+export class Logger {
+  constructor() {
+    const stream = new Stdout();
+
+    // @ts-ignore;
+    process.stdout.write = process.stderr.write = stream.write.bind(stream);
+    console = new console.Console(new Stdout(), new Stdout());
+  }
+
+  logs(): string {
+    this.restore();
+    return stdout.join("");
+  }
+
+  restore() {
+    console = originalConsole;
+    process.stdout.write = originalStdout;
+    process.stderr.write = originalStderr;
+  }
+}