http: implement capture rejections for 'request' event

PR-URL: #27867
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

lib/_http_server.js

@@ -29,6 +29,7 @@ const {
 } = primordials;
 
 const net = require('net');
+const EE = require('events');
 const assert = require('internal/assert');
 const {
   parsers,
@@ -358,6 +359,26 @@ Server.prototype.setTimeout = function setTimeout(msecs, callback) {
   return this;
 };
 
+Server.prototype[EE.captureRejectionSymbol] = function(
+  err, event, req, res) {
+
+  switch (event) {
+    case 'request':
+      if (!res.headersSent && !res.writableEnded) {
+        // Don't leak headers.
+        for (const name of res.getHeaderNames()) {
+          res.removeHeader(name);
+        }
+        res.statusCode = 500;
+        res.end(STATUS_CODES[500]);
+      } else {
+        res.destroy();
+      }
+      break;
+    default:
+      this.emit('error', err);
+  }
+};
 
 function connectionListener(socket) {
   defaultTriggerAsyncIdScope(

test/parallel/test-http-server-capture-rejections.js

@@ -0,0 +1,108 @@
+'use strict';
+
+const common = require('../common');
+const events = require('events');
+const { createServer, request } = require('http');
+const assert = require('assert');
+
+events.captureRejections = true;
+
+{
+  const server = createServer(common.mustCall(async (req, res) => {
+    // We will test that this header is cleaned up before forwarding.
+    res.setHeader('content-type', 'application/json');
+    throw new Error('kaboom');
+  }));
+
+  server.listen(0, common.mustCall(() => {
+    const req = request({
+      method: 'GET',
+      host: server.address().host,
+      port: server.address().port
+    });
+
+    req.end();
+
+    req.on('response', common.mustCall((res) => {
+      assert.strictEqual(res.statusCode, 500);
+      assert.strictEqual(res.headers.hasOwnProperty('content-type'), false);
+      let data = '';
+      res.setEncoding('utf8');
+      res.on('data', common.mustCall((chunk) => {
+        data += chunk;
+      }));
+      res.on('end', common.mustCall(() => {
+        assert.strictEqual(data, 'Internal Server Error');
+        server.close();
+      }));
+    }));
+  }));
+}
+
+{
+  let resolve;
+  const latch = new Promise((_resolve) => {
+    resolve = _resolve;
+  });
+  const server = createServer(common.mustCall(async (req, res) => {
+    server.close();
+
+    // We will test that this header is cleaned up before forwarding.
+    res.setHeader('content-type', 'application/json');
+    res.write('{');
+    req.resume();
+
+    // Wait so the data is on the wire
+    await latch;
+
+    throw new Error('kaboom');
+  }));
+
+  server.listen(0, common.mustCall(() => {
+    const req = request({
+      method: 'GET',
+      host: server.address().host,
+      port: server.address().port
+    });
+
+    req.end();
+
+    req.on('response', common.mustCall((res) => {
+      assert.strictEqual(res.statusCode, 200);
+      assert.strictEqual(res.headers['content-type'], 'application/json');
+      resolve();
+
+      let data = '';
+      res.setEncoding('utf8');
+      res.on('data', common.mustCall((chunk) => {
+        data += chunk;
+      }));
+
+      req.on('close', common.mustCall(() => {
+        assert.strictEqual(data, '{');
+      }));
+    }));
+  }));
+}
+
+{
+  const server = createServer(common.mustCall(async (req, res) => {
+    // We will test that this header is cleaned up before forwarding.
+    res.writeHead(200);
+    throw new Error('kaboom');
+  }));
+
+  server.listen(0, common.mustCall(() => {
+    const req = request({
+      method: 'GET',
+      host: server.address().host,
+      port: server.address().port
+    });
+
+    req.end();
+    req.on('error', common.mustCall((err) => {
+      assert.strictEqual(err.code, 'ECONNRESET');
+      server.close();
+    }));
+  }));
+}