fix: add automatic Connection header for Node.js HTTP compatibility

src/bun.js/bindings/NodeHTTP.cpp

@@ -1070,6 +1070,8 @@ static void NodeHTTPServer__writeHead(
     }
     response->writeStatus(std::string_view(statusMessage, statusMessageLength));
 
+    bool hasConnectionHeader = false;
+
     if (headersObject) {
         if (auto* fetchHeaders = jsDynamicCast<WebCore::JSFetchHeaders*>(headersObject)) {
             writeFetchHeadersToUWSResponse<isSSL>(fetchHeaders->wrapped(), response);
@@ -1095,6 +1097,11 @@ static void NodeHTTPServer__writeHead(
                 String value = headerValue.toWTFString(globalObject);
                 RETURN_IF_EXCEPTION(scope, false);
 
+                // Check if this is a Connection header
+                if (WTF::equalIgnoringASCIICase(key, "connection"_s)) {
+                    hasConnectionHeader = true;
+                }
+
                 writeResponseHeader<isSSL>(response, key, value);
 
                 return true;
@@ -1114,11 +1121,29 @@ static void NodeHTTPServer__writeHead(
                 String key = propertyNames[i].string();
                 String value = headerValue.toWTFString(globalObject);
                 RETURN_IF_EXCEPTION(scope, void());
+
+                // Check if this is a Connection header
+                if (WTF::equalIgnoringASCIICase(key, "connection"_s)) {
+                    hasConnectionHeader = true;
+                }
+
                 writeResponseHeader<isSSL>(response, key, value);
             }
         }
     }
 
+    // Automatically add Connection header if not already set by user
+    if (!hasConnectionHeader) {
+        auto* data = response->getHttpResponseData();
+        bool shouldClose = data->state & uWS::HttpResponseData<isSSL>::HTTP_CONNECTION_CLOSE;
+
+        if (!shouldClose) {
+            writeResponseHeader<isSSL>(response, "connection"_s, "keep-alive"_s);
+        } else {
+            writeResponseHeader<isSSL>(response, "connection"_s, "close"_s);
+        }
+    }
+
     RELEASE_AND_RETURN(scope, void());
 }
 

test/js/node/test/parallel/test-http-automatic-headers.js

@@ -0,0 +1,31 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+
+const server = http.createServer(common.mustCall((req, res) => {
+  res.setHeader('X-Date', 'foo');
+  res.setHeader('X-Connection', 'bar');
+  res.setHeader('X-Content-Length', 'baz');
+  res.end();
+}));
+server.listen(0);
+
+server.on('listening', common.mustCall(() => {
+  const agent = new http.Agent({ port: server.address().port, maxSockets: 1 });
+  http.get({
+    port: server.address().port,
+    path: '/hello',
+    agent: agent
+  }, common.mustCall((res) => {
+    assert.strictEqual(res.statusCode, 200);
+    assert.strictEqual(res.headers['x-date'], 'foo');
+    assert.strictEqual(res.headers['x-connection'], 'bar');
+    assert.strictEqual(res.headers['x-content-length'], 'baz');
+    assert(res.headers.date);
+    assert.strictEqual(res.headers.connection, 'keep-alive');
+    assert.strictEqual(res.headers['content-length'], '0');
+    server.close();
+    agent.destroy();
+  }));
+}));

test/js/node/test/parallel/test-http-remove-connection-header-persists-connection.js

@@ -0,0 +1,69 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const net = require('net');
+const http = require('http');
+
+const server = http.createServer(function(request, response) {
+  response.removeHeader('connection');
+
+  if (request.httpVersion === '1.0') {
+    const socket = request.socket;
+    response.on('finish', common.mustCall(function() {
+      assert.ok(socket.writableEnded);
+    }));
+  }
+
+  response.end('beep boop\n');
+});
+
+const agent = new http.Agent({ keepAlive: true });
+
+function makeHttp11Request(cb) {
+  http.get({
+    port: server.address().port,
+    agent
+  }, function(res) {
+    const socket = res.socket;
+
+    assert.strictEqual(res.statusCode, 200);
+    assert.strictEqual(res.headers.connection, undefined);
+
+    res.setEncoding('ascii');
+    let response = '';
+    res.on('data', function(chunk) {
+      response += chunk;
+    });
+    res.on('end', function() {
+      assert.strictEqual(response, 'beep boop\n');
+
+      process.nextTick(function() {
+        cb(socket);
+      });
+    });
+  });
+}
+
+function makeHttp10Request(cb) {
+  const socket = net.connect({ port: server.address().port }, function() {
+    socket.write('GET / HTTP/1.0\r\n' +
+               'Host: localhost:' + server.address().port + '\r\n' +
+                '\r\n');
+    socket.resume();
+
+    socket.on('close', cb);
+  });
+}
+
+server.listen(0, function() {
+  makeHttp11Request(function(firstSocket) {
+    makeHttp11Request(function(secondSocket) {
+      assert.strictEqual(firstSocket, secondSocket);
+
+      makeHttp10Request(function() {
+        server.close();
+      });
+    });
+  });
+});