diff --git a/test/common/README.md b/test/common/README.md
index 32ca6711573daa..1ec603a3bd8a02 100644
--- a/test/common/README.md
+++ b/test/common/README.md
@@ -338,6 +338,42 @@ The realpath of the 'tmp' directory.
 
 Name of the temp directory used by tests.
 
+## Countdown Module
+
+The `Countdown` module provides a simple countdown mechanism for tests that
+require a particular action to be taken after a given number of completed
+tasks (for instance, shutting down an HTTP server after a specific number of
+requests).
+
+<!-- eslint-disable strict, required-modules -->
+```js
+const Countdown = require('../common/countdown');
+
+function doSomething() {
+  console.log('.');
+}
+
+const countdown = new Countdown(2, doSomething);
+countdown.dec();
+countdown.dec();
+```
+
+### new Countdown(limit, callback)
+
+* `limit` {number}
+* `callback` {function}
+
+Creates a new `Countdown` instance.
+
+### Countdown.prototype.dec()
+
+Decrements the `Countdown` counter.
+
+### Coutndown.prototype.remaining
+
+Specifies the remaining number of times `Countdown.prototype.dec()` must be
+called before the callback is invoked.
+
 ## WPT Module
 
 The wpt.js module is a port of parts of
diff --git a/test/common/countdown.js b/test/common/countdown.js
new file mode 100644
index 00000000000000..6a22be0a07eb0b
--- /dev/null
+++ b/test/common/countdown.js
@@ -0,0 +1,27 @@
+/* eslint-disable required-modules */
+'use strict';
+
+const assert = require('assert');
+const kLimit = Symbol('limit');
+const kCallback = Symbol('callback');
+
+class Countdown {
+  constructor(limit, cb) {
+    assert.strictEqual(typeof limit, 'number');
+    assert.strictEqual(typeof cb, 'function');
+    this[kLimit] = limit;
+    this[kCallback] = cb;
+  }
+
+  dec() {
+    assert(this[kLimit] > 0, 'Countdown expired');
+    if (--this[kLimit] === 0)
+      this[kCallback]();
+  }
+
+  get remaining() {
+    return this[kLimit];
+  }
+}
+
+module.exports = Countdown;
diff --git a/test/parallel/test-common-countdown.js b/test/parallel/test-common-countdown.js
new file mode 100644
index 00000000000000..ec0543f36fec74
--- /dev/null
+++ b/test/parallel/test-common-countdown.js
@@ -0,0 +1,15 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const Countdown = require('../common/countdown');
+
+let done = '';
+
+const countdown = new Countdown(2, common.mustCall(() => done = true));
+assert.strictEqual(countdown.remaining, 2);
+countdown.dec();
+assert.strictEqual(countdown.remaining, 1);
+countdown.dec();
+assert.strictEqual(countdown.remaining, 0);
+assert.strictEqual(done, true);
diff --git a/test/parallel/test-http-abort-client.js b/test/parallel/test-http-abort-client.js
index 644b73f2c9995d..eda08ced97c55c 100644
--- a/test/parallel/test-http-abort-client.js
+++ b/test/parallel/test-http-abort-client.js
@@ -24,42 +24,24 @@ const common = require('../common');
 const http = require('http');
 
 let serverRes;
-const server = http.Server(function(req, res) {
-  console.log('Server accepted request.');
+const server = http.Server((req, res) => {
   serverRes = res;
   res.writeHead(200);
   res.write('Part of my res.');
 });
 
-server.listen(0, common.mustCall(function() {
+server.listen(0, common.mustCall(() => {
   http.get({
-    port: this.address().port,
+    port: server.address().port,
     headers: { connection: 'keep-alive' }
-  }, common.mustCall(function(res) {
+  }, common.mustCall((res) => {
     server.close();
     serverRes.destroy();
 
-    console.log(`Got res: ${res.statusCode}`);
-    console.dir(res.headers);
-
-    res.on('data', function(chunk) {
-      console.log(`Read ${chunk.length} bytes`);
-      console.log(' chunk=%j', chunk.toString());
-    });
-
-    res.on('end', function() {
-      console.log('Response ended.');
-    });
-
-    res.on('aborted', function() {
-      console.log('Response aborted.');
-    });
-
-    res.socket.on('close', function() {
-      console.log('socket closed, but not res');
-    });
-
-    // it would be nice if this worked:
+    res.resume();
+    res.on('end', common.mustCall());
+    res.on('aborted', common.mustCall());
     res.on('close', common.mustCall());
+    res.socket.on('close', common.mustCall());
   }));
 }));
diff --git a/test/parallel/test-http-abort-queued.js b/test/parallel/test-http-abort-queued.js
index 9b15fe2e7440a9..224d0b606ea744 100644
--- a/test/parallel/test-http-abort-queued.js
+++ b/test/parallel/test-http-abort-queued.js
@@ -20,13 +20,13 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const http = require('http');
 
 let complete;
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer((req, res) => {
   // We should not see the queued /thatotherone request within the server
   // as it should be aborted before it is sent.
   assert.strictEqual(req.url, '/');
@@ -40,9 +40,7 @@ const server = http.createServer(function(req, res) {
 });
 
 
-server.listen(0, function() {
-  console.log('listen', server.address().port);
-
+server.listen(0, () => {
   const agent = new http.Agent({ maxSockets: 1 });
   assert.strictEqual(Object.keys(agent.sockets).length, 0);
 
@@ -55,7 +53,7 @@ server.listen(0, function() {
   };
 
   const req1 = http.request(options);
-  req1.on('response', function(res1) {
+  req1.on('response', (res1) => {
     assert.strictEqual(Object.keys(agent.sockets).length, 1);
     assert.strictEqual(Object.keys(agent.requests).length, 0);
 
@@ -69,7 +67,9 @@ server.listen(0, function() {
     assert.strictEqual(Object.keys(agent.sockets).length, 1);
     assert.strictEqual(Object.keys(agent.requests).length, 1);
 
-    req2.on('error', function(err) {
+    // TODO(jasnell): This event does not appear to currently be triggered.
+    // is this handler actually required?
+    req2.on('error', (err) => {
       // This is expected in response to our explicit abort call
       assert.strictEqual(err.code, 'ECONNRESET');
     });
@@ -80,25 +80,16 @@ server.listen(0, function() {
     assert.strictEqual(Object.keys(agent.sockets).length, 1);
     assert.strictEqual(Object.keys(agent.requests).length, 1);
 
-    console.log(`Got res: ${res1.statusCode}`);
-    console.dir(res1.headers);
-
-    res1.on('data', function(chunk) {
-      console.log(`Read ${chunk.length} bytes`);
-      console.log(' chunk=%j', chunk.toString());
-      complete();
-    });
+    res1.on('data', (chunk) => complete());
 
-    res1.on('end', function() {
-      console.log('Response ended.');
-
-      setTimeout(function() {
+    res1.on('end', common.mustCall(() => {
+      setTimeout(common.mustCall(() => {
         assert.strictEqual(Object.keys(agent.sockets).length, 0);
         assert.strictEqual(Object.keys(agent.requests).length, 0);
 
         server.close();
-      }, 100);
-    });
+      }), 100);
+    }));
   });
 
   req1.end();
diff --git a/test/parallel/test-http-abort-stream-end.js b/test/parallel/test-http-abort-stream-end.js
index ea14fe0ca99a74..8d2704a1ee7d17 100644
--- a/test/parallel/test-http-abort-stream-end.js
+++ b/test/parallel/test-http-abort-stream-end.js
@@ -20,7 +20,7 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 
 const http = require('http');
@@ -28,20 +28,21 @@ const http = require('http');
 const maxSize = 1024;
 let size = 0;
 
-const s = http.createServer(function(req, res) {
-  this.close();
+const server = http.createServer(common.mustCall((req, res) => {
+  server.close();
 
   res.writeHead(200, { 'Content-Type': 'text/plain' });
   for (let i = 0; i < maxSize; i++) {
-    res.write('x' + i);
+    res.write(`x${i}`);
   }
   res.end();
-});
+}));
 
 let aborted = false;
-s.listen(0, function() {
-  const req = http.get('http://localhost:' + s.address().port, function(res) {
-    res.on('data', function(chunk) {
+server.listen(0, () => {
+
+  const res = common.mustCall((res) => {
+    res.on('data', (chunk) => {
       size += chunk.length;
       assert(!aborted, 'got data after abort');
       if (size > maxSize) {
@@ -50,11 +51,9 @@ s.listen(0, function() {
         size = maxSize;
       }
     });
+
+    req.on('abort', common.mustCall(() => assert.strictEqual(size, maxSize)));
   });
-});
 
-process.on('exit', function() {
-  assert(aborted);
-  assert.strictEqual(size, maxSize);
-  console.log('ok');
+  const req = http.get(`http://localhost:${server.address().port}`, res);
 });
diff --git a/test/parallel/test-http-after-connect.js b/test/parallel/test-http-after-connect.js
index d8a711c8d69a26..324186bab72324 100644
--- a/test/parallel/test-http-after-connect.js
+++ b/test/parallel/test-http-after-connect.js
@@ -23,61 +23,51 @@
 const common = require('../common');
 const assert = require('assert');
 const http = require('http');
+const Countdown = require('../common/countdown');
 
-let clientResponses = 0;
-
-const server = http.createServer(common.mustCall(function(req, res) {
-  console.error('Server got GET request');
+const server = http.createServer(common.mustCall((req, res) => {
   req.resume();
   res.writeHead(200);
   res.write('');
-  setTimeout(function() {
-    res.end(req.url);
-  }, 50);
+  setTimeout(() => res.end(req.url), 50);
 }, 2));
-server.on('connect', common.mustCall(function(req, socket) {
-  console.error('Server got CONNECT request');
+
+const countdown = new Countdown(2, common.mustCall(() => server.close()));
+
+server.on('connect', common.mustCall((req, socket) => {
   socket.write('HTTP/1.1 200 Connection established\r\n\r\n');
   socket.resume();
-  socket.on('end', function() {
-    socket.end();
-  });
+  socket.on('end', () => socket.end());
 }));
-server.listen(0, function() {
+
+server.listen(0, common.mustCall(() => {
   const req = http.request({
-    port: this.address().port,
+    port: server.address().port,
     method: 'CONNECT',
     path: 'google.com:80'
   });
-  req.on('connect', common.mustCall(function(res, socket) {
-    console.error('Client got CONNECT response');
+  req.on('connect', common.mustCall((res, socket) => {
     socket.end();
-    socket.on('end', function() {
+    socket.on('end', common.mustCall(() => {
       doRequest(0);
       doRequest(1);
-    });
+    }));
     socket.resume();
   }));
   req.end();
-});
+}));
 
 function doRequest(i) {
   http.get({
     port: server.address().port,
     path: `/request${i}`
-  }, common.mustCall(function(res) {
-    console.error('Client got GET response');
+  }, common.mustCall((res) => {
     let data = '';
     res.setEncoding('utf8');
-    res.on('data', function(chunk) {
-      data += chunk;
-    });
-    res.on('end', function() {
+    res.on('data', (chunk) => data += chunk);
+    res.on('end', common.mustCall(() => {
       assert.strictEqual(data, `/request${i}`);
-      ++clientResponses;
-      if (clientResponses === 2) {
-        server.close();
-      }
-    });
+      countdown.dec();
+    }));
   }));
 }
diff --git a/test/parallel/test-http-agent-destroyed-socket.js b/test/parallel/test-http-agent-destroyed-socket.js
index 163664b7bd7c72..7970ce8bae0fcb 100644
--- a/test/parallel/test-http-agent-destroyed-socket.js
+++ b/test/parallel/test-http-agent-destroyed-socket.js
@@ -23,35 +23,30 @@
 const common = require('../common');
 const assert = require('assert');
 const http = require('http');
+const Countdown = require('../common/countdown');
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   res.writeHead(200, { 'Content-Type': 'text/plain' });
   res.end('Hello World\n');
-}).listen(0, common.mustCall(function() {
+}, 2)).listen(0, common.mustCall(() => {
   const agent = new http.Agent({ maxSockets: 1 });
 
-  agent.on('free', function(socket) {
-    console.log('freeing socket. destroyed? ', socket.destroyed);
-  });
+  agent.on('free', common.mustCall(3));
 
   const requestOptions = {
     agent: agent,
     host: 'localhost',
-    port: this.address().port,
+    port: server.address().port,
     path: '/'
   };
 
-  const request1 = http.get(requestOptions, common.mustCall(function(response) {
+  const request1 = http.get(requestOptions, common.mustCall((response) => {
     // assert request2 is queued in the agent
     const key = agent.getName(requestOptions);
     assert.strictEqual(agent.requests[key].length, 1);
-    console.log('got response1');
-    request1.socket.on('close', function() {
-      console.log('request1 socket closed');
-    });
-    response.pipe(process.stdout);
-    response.on('end', common.mustCall(function() {
-      console.log('response1 done');
+    request1.socket.on('close', common.mustCall());
+    response.resume();
+    response.on('end', common.mustCall(() => {
       /////////////////////////////////
       //
       // THE IMPORTANT PART
@@ -65,43 +60,29 @@ const server = http.createServer(function(req, res) {
       // is triggered.
       request1.socket.destroy();
 
-      response.once('close', function() {
+      // TODO(jasnell): This close event does not appear to be triggered.
+      // is it necessary?
+      response.once('close', () => {
         // assert request2 was removed from the queue
         assert(!agent.requests[key]);
-        console.log("waiting for request2.onSocket's nextTick");
-        process.nextTick(common.mustCall(function() {
+        process.nextTick(() => {
           // assert that the same socket was not assigned to request2,
           // since it was destroyed.
           assert.notStrictEqual(request1.socket, request2.socket);
           assert(!request2.socket.destroyed, 'the socket is destroyed');
-        }));
+        });
       });
     }));
   }));
 
-  const request2 = http.get(requestOptions, common.mustCall(function(response) {
+  const request2 = http.get(requestOptions, common.mustCall((response) => {
     assert(!request2.socket.destroyed);
     assert(request1.socket.destroyed);
     // assert not reusing the same socket, since it was destroyed.
     assert.notStrictEqual(request1.socket, request2.socket);
-    console.log('got response2');
-    let gotClose = false;
-    let gotResponseEnd = false;
-    request2.socket.on('close', function() {
-      console.log('request2 socket closed');
-      gotClose = true;
-      done();
-    });
-    response.pipe(process.stdout);
-    response.on('end', function() {
-      console.log('response2 done');
-      gotResponseEnd = true;
-      done();
-    });
-
-    function done() {
-      if (gotResponseEnd && gotClose)
-        server.close();
-    }
+    const countdown = new Countdown(2, common.mustCall(() => server.close()));
+    request2.socket.on('close', common.mustCall(() => countdown.dec()));
+    response.on('end', common.mustCall(() => countdown.dec()));
+    response.resume();
   }));
 }));
diff --git a/test/parallel/test-http-agent-error-on-idle.js b/test/parallel/test-http-agent-error-on-idle.js
index 2f270c0d30ca0b..fce5e8f0324f5c 100644
--- a/test/parallel/test-http-agent-error-on-idle.js
+++ b/test/parallel/test-http-agent-error-on-idle.js
@@ -1,32 +1,31 @@
 'use strict';
-require('../common');
+
+const common = require('../common');
 const assert = require('assert');
 const http = require('http');
 const Agent = http.Agent;
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   res.end('hello world');
-});
+}, 2));
 
-server.listen(0, function() {
-  const agent = new Agent({
-    keepAlive: true,
-  });
+server.listen(0, () => {
+  const agent = new Agent({ keepAlive: true });
 
   const requestParams = {
     host: 'localhost',
-    port: this.address().port,
+    port: server.address().port,
     agent: agent,
     path: '/'
   };
 
   const socketKey = agent.getName(requestParams);
 
-  get(function(res) {
+  http.get(requestParams, common.mustCall((res) => {
     assert.strictEqual(res.statusCode, 200);
     res.resume();
-    res.on('end', function() {
-      process.nextTick(function() {
+    res.on('end', common.mustCall(() => {
+      process.nextTick(common.mustCall(() => {
         const freeSockets = agent.freeSockets[socketKey];
         assert.strictEqual(freeSockets.length, 1,
                            `expect a free socket on ${socketKey}`);
@@ -35,14 +34,10 @@ server.listen(0, function() {
         const freeSocket = freeSockets[0];
         freeSocket.emit('error', new Error('ECONNRESET: test'));
 
-        get(done);
-      });
-    });
-  });
-
-  function get(callback) {
-    return http.get(requestParams, callback);
-  }
+        http.get(requestParams, done);
+      }));
+    }));
+  }));
 
   function done() {
     assert.strictEqual(Object.keys(agent.freeSockets).length, 0,
@@ -50,6 +45,5 @@ server.listen(0, function() {
 
     agent.destroy();
     server.close();
-    process.exit(0);
   }
 });
diff --git a/test/parallel/test-http-agent-false.js b/test/parallel/test-http-agent-false.js
index 0e633c7c103b76..4d92d5e01e03e2 100644
--- a/test/parallel/test-http-agent-false.js
+++ b/test/parallel/test-http-agent-false.js
@@ -20,8 +20,7 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
-const assert = require('assert');
+const common = require('../common');
 const http = require('http');
 
 // sending `agent: false` when `port: null` is also passed in (i.e. the result
@@ -35,20 +34,13 @@ const opts = {
   agent: false
 };
 
-let good = false;
-process.on('exit', function() {
-  assert(good, 'expected either an "error" or "response" event');
-});
-
 // we just want an "error" (no local HTTP server on port 80) or "response"
 // to happen (user happens ot have HTTP server running on port 80).
 // As long as the process doesn't crash from a C++ assertion then we're good.
 const req = http.request(opts);
-req.on('response', function(res) {
-  good = true;
-});
-req.on('error', function(err) {
-  // an "error" event is ok, don't crash the process
-  good = true;
-});
+
+// Will be called by either the response event or error event, not both
+const oneResponse = common.mustCall();
+req.on('response', oneResponse);
+req.on('error', oneResponse);
 req.end();
diff --git a/test/parallel/test-http-agent-keepalive.js b/test/parallel/test-http-agent-keepalive.js
index c695b55bfa5ee7..2c8b6c1cc98d2d 100644
--- a/test/parallel/test-http-agent-keepalive.js
+++ b/test/parallel/test-http-agent-keepalive.js
@@ -34,19 +34,17 @@ const agent = new Agent({
   maxFreeSockets: 5
 });
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   if (req.url === '/error') {
     res.destroy();
     return;
   } else if (req.url === '/remote_close') {
     // cache the socket, close it after a short delay
     const socket = res.connection;
-    setImmediate(function() {
-      socket.end();
-    });
+    setImmediate(common.mustCall(() => socket.end()));
   }
   res.end('hello world');
-});
+}, 4));
 
 function get(path, callback) {
   return http.get({
@@ -65,82 +63,75 @@ function checkDataAndSockets(body) {
 
 function second() {
   // request second, use the same socket
-  get('/second', function(res) {
+  get('/second', common.mustCall((res) => {
     assert.strictEqual(res.statusCode, 200);
     res.on('data', checkDataAndSockets);
-    res.on('end', function() {
+    res.on('end', common.mustCall(() => {
       assert.strictEqual(agent.sockets[name].length, 1);
       assert.strictEqual(agent.freeSockets[name], undefined);
-      process.nextTick(function() {
+      process.nextTick(common.mustCall(() => {
         assert.strictEqual(agent.sockets[name], undefined);
         assert.strictEqual(agent.freeSockets[name].length, 1);
         remoteClose();
-      });
-    });
-  });
+      }));
+    }));
+  }));
 }
 
 function remoteClose() {
   // mock remote server close the socket
-  get('/remote_close', function(res) {
+  get('/remote_close', common.mustCall((res) => {
     assert.deepStrictEqual(res.statusCode, 200);
     res.on('data', checkDataAndSockets);
-    res.on('end', function() {
+    res.on('end', common.mustCall(() => {
       assert.strictEqual(agent.sockets[name].length, 1);
       assert.strictEqual(agent.freeSockets[name], undefined);
-      process.nextTick(function() {
+      process.nextTick(common.mustCall(() => {
         assert.strictEqual(agent.sockets[name], undefined);
         assert.strictEqual(agent.freeSockets[name].length, 1);
         // waitting remote server close the socket
-        setTimeout(function() {
+        setTimeout(common.mustCall(() => {
           assert.strictEqual(agent.sockets[name], undefined);
           assert.strictEqual(agent.freeSockets[name], undefined,
                              'freeSockets is not empty');
           remoteError();
-        }, common.platformTimeout(200));
-      });
-    });
-  });
+        }), common.platformTimeout(200));
+      }));
+    }));
+  }));
 }
 
 function remoteError() {
   // remove server will destroy ths socket
-  const req = get('/error', function(res) {
-    throw new Error('should not call this function');
-  });
-  req.on('error', function(err) {
-    assert.ok(err);
+  const req = get('/error', common.mustNotCall());
+  req.on('error', common.mustCall((err) => {
+    assert(err);
     assert.strictEqual(err.message, 'socket hang up');
     assert.strictEqual(agent.sockets[name].length, 1);
     assert.strictEqual(agent.freeSockets[name], undefined);
     // Wait socket 'close' event emit
-    setTimeout(function() {
+    setTimeout(common.mustCall(() => {
       assert.strictEqual(agent.sockets[name], undefined);
       assert.strictEqual(agent.freeSockets[name], undefined);
-      done();
-    }, common.platformTimeout(1));
-  });
-}
-
-function done() {
-  console.log('http keepalive agent test success.');
-  process.exit(0);
+      server.close();
+    }), common.platformTimeout(1));
+  }));
 }
 
-server.listen(0, function() {
+server.listen(0, common.mustCall(() => {
   name = `localhost:${server.address().port}:`;
   // request first, and keep alive
-  get('/first', function(res) {
+  get('/first', common.mustCall((res) => {
     assert.strictEqual(res.statusCode, 200);
     res.on('data', checkDataAndSockets);
-    res.on('end', function() {
+    res.on('end', common.mustCall(() => {
       assert.strictEqual(agent.sockets[name].length, 1);
       assert.strictEqual(agent.freeSockets[name], undefined);
-      process.nextTick(function() {
+      process.nextTick(common.mustCall(() => {
         assert.strictEqual(agent.sockets[name], undefined);
         assert.strictEqual(agent.freeSockets[name].length, 1);
         second();
-      });
-    });
-  });
-});
+      }));
+    }));
+  }));
+}));
diff --git a/test/parallel/test-http-agent-maxsockets-regress-4050.js b/test/parallel/test-http-agent-maxsockets-regress-4050.js
index fd3a8c33f3e39a..57a90e4b05c79f 100644
--- a/test/parallel/test-http-agent-maxsockets-regress-4050.js
+++ b/test/parallel/test-http-agent-maxsockets-regress-4050.js
@@ -1,7 +1,8 @@
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const http = require('http');
+const Countdown = require('../common/countdown');
 
 const MAX_SOCKETS = 2;
 
@@ -12,9 +13,11 @@ const agent = new http.Agent({
   maxFreeSockets: 2
 });
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   res.end('hello world');
-});
+}, 6));
+
+const countdown = new Countdown(6, common.mustCall(() => server.close()));
 
 function get(path, callback) {
   return http.get({
@@ -25,19 +28,14 @@ function get(path, callback) {
   }, callback);
 }
 
-server.listen(0, function() {
-  let finished = 0;
-  const num_requests = 6;
-  for (let i = 0; i < num_requests; i++) {
-    const request = get('/1', function() {
-    });
-    request.on('response', function() {
+server.listen(0, common.mustCall(() => {
+  for (let i = 0; i < 6; i++) {
+    const request = get('/1', common.mustCall());
+    request.on('response', common.mustCall(() => {
       request.abort();
       const sockets = agent.sockets[Object.keys(agent.sockets)[0]];
       assert(sockets.length <= MAX_SOCKETS);
-      if (++finished === num_requests) {
-        server.close();
-      }
-    });
+      countdown.dec();
+    }));
   }
-});
+}));
diff --git a/test/parallel/test-http-agent-maxsockets.js b/test/parallel/test-http-agent-maxsockets.js
index 513906160048d9..66fffba250513f 100644
--- a/test/parallel/test-http-agent-maxsockets.js
+++ b/test/parallel/test-http-agent-maxsockets.js
@@ -1,7 +1,8 @@
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const http = require('http');
+const Countdown = require('../common/countdown');
 
 const agent = new http.Agent({
   keepAlive: true,
@@ -10,9 +11,9 @@ const agent = new http.Agent({
   maxFreeSockets: 2
 });
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   res.end('hello world');
-});
+}, 2));
 
 function get(path, callback) {
   return http.get({
@@ -23,32 +24,25 @@ function get(path, callback) {
   }, callback);
 }
 
-let count = 0;
-function done() {
-  if (++count !== 2) {
-    return;
-  }
+const countdown = new Countdown(2, common.mustCall(() => {
   const freepool = agent.freeSockets[Object.keys(agent.freeSockets)[0]];
   assert.strictEqual(freepool.length, 2,
                      `expect keep 2 free sockets, but got ${freepool.length}`);
   agent.destroy();
   server.close();
+}));
+
+function dec() {
+  process.nextTick(() => countdown.dec());
 }
 
-server.listen(0, function() {
-  get('/1', function(res) {
-    assert.strictEqual(res.statusCode, 200);
-    res.resume();
-    res.on('end', function() {
-      process.nextTick(done);
-    });
-  });
+function onGet(res) {
+  assert.strictEqual(res.statusCode, 200);
+  res.resume();
+  res.on('end', common.mustCall(dec));
+}
 
-  get('/2', function(res) {
-    assert.strictEqual(res.statusCode, 200);
-    res.resume();
-    res.on('end', function() {
-      process.nextTick(done);
-    });
-  });
-});
+server.listen(0, common.mustCall(() => {
+  get('/1', common.mustCall(onGet));
+  get('/2', common.mustCall(onGet));
+}));
diff --git a/test/parallel/test-http-agent-no-protocol.js b/test/parallel/test-http-agent-no-protocol.js
index 4630ef8ee6388d..b5a144abc93d9e 100644
--- a/test/parallel/test-http-agent-no-protocol.js
+++ b/test/parallel/test-http-agent-no-protocol.js
@@ -24,17 +24,17 @@ const common = require('../common');
 const http = require('http');
 const url = require('url');
 
-const server = http.createServer(common.mustCall(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   res.end();
-})).listen(0, '127.0.0.1', common.mustCall(function() {
-  const opts = url.parse(`http://127.0.0.1:${this.address().port}/`);
+})).listen(0, '127.0.0.1', common.mustCall(() => {
+  const opts = url.parse(`http://127.0.0.1:${server.address().port}/`);
 
   // remove the `protocol` field… the `http` module should fall back
   // to "http:", as defined by the global, default `http.Agent` instance.
   opts.agent = new http.Agent();
   opts.agent.protocol = null;
 
-  http.get(opts, common.mustCall(function(res) {
+  http.get(opts, common.mustCall((res) => {
     res.resume();
     server.close();
   }));
diff --git a/test/parallel/test-http-agent-null.js b/test/parallel/test-http-agent-null.js
index 784dc32211c807..0f87d098134b50 100644
--- a/test/parallel/test-http-agent-null.js
+++ b/test/parallel/test-http-agent-null.js
@@ -23,14 +23,14 @@
 const common = require('../common');
 const http = require('http');
 
-const server = http.createServer(common.mustCall(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   res.end();
-})).listen(0, common.mustCall(function() {
+})).listen(0, common.mustCall(() => {
   const options = {
     agent: null,
-    port: this.address().port
+    port: server.address().port
   };
-  http.get(options, common.mustCall(function(res) {
+  http.get(options, common.mustCall((res) => {
     res.resume();
     server.close();
   }));
diff --git a/test/parallel/test-http-automatic-headers.js b/test/parallel/test-http-automatic-headers.js
index 37a5c43901c33d..5a6a8e524c76ee 100644
--- a/test/parallel/test-http-automatic-headers.js
+++ b/test/parallel/test-http-automatic-headers.js
@@ -1,23 +1,23 @@
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const http = require('http');
 
-const server = http.createServer(function(req, res) {
+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', function() {
-  const agent = new http.Agent({ port: this.address().port, maxSockets: 1 });
+server.on('listening', common.mustCall(() => {
+  const agent = new http.Agent({ port: server.address().port, maxSockets: 1 });
   http.get({
-    port: this.address().port,
+    port: server.address().port,
     path: '/hello',
     agent: agent
-  }, function(res) {
+  }, common.mustCall((res) => {
     assert.strictEqual(res.statusCode, 200);
     assert.strictEqual(res.headers['x-date'], 'foo');
     assert.strictEqual(res.headers['x-connection'], 'bar');
@@ -27,5 +27,5 @@ server.on('listening', function() {
     assert.strictEqual(res.headers['content-length'], '0');
     server.close();
     agent.destroy();
-  });
-});
+  }));
+}));
diff --git a/test/parallel/test-http-blank-header.js b/test/parallel/test-http-blank-header.js
index 1659dc5ed5fd5d..ff86193a1bad4a 100644
--- a/test/parallel/test-http-blank-header.js
+++ b/test/parallel/test-http-blank-header.js
@@ -25,34 +25,29 @@ const assert = require('assert');
 const http = require('http');
 const net = require('net');
 
-const server = http.createServer(common.mustCall(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   assert.strictEqual('GET', req.method);
   assert.strictEqual('/blah', req.url);
   assert.deepStrictEqual({
-    host: 'mapdevel.trolologames.ru:443',
-    origin: 'http://mapdevel.trolologames.ru',
+    host: 'example.org:443',
+    origin: 'http://example.org',
     cookie: ''
   }, req.headers);
 }));
 
 
-server.listen(0, function() {
-  const c = net.createConnection(this.address().port);
+server.listen(0, common.mustCall(() => {
+  const c = net.createConnection(server.address().port);
 
-  c.on('connect', function() {
+  c.on('connect', common.mustCall(() => {
     c.write('GET /blah HTTP/1.1\r\n' +
-            'Host: mapdevel.trolologames.ru:443\r\n' +
+            'Host: example.org:443\r\n' +
             'Cookie:\r\n' +
-            'Origin: http://mapdevel.trolologames.ru\r\n' +
+            'Origin: http://example.org\r\n' +
             '\r\n\r\nhello world'
     );
-  });
+  }));
 
-  c.on('end', function() {
-    c.end();
-  });
-
-  c.on('close', function() {
-    server.close();
-  });
-});
+  c.on('end', common.mustCall(() => c.end()));
+  c.on('close', common.mustCall(() => server.close()));
+}));
diff --git a/test/parallel/test-http-buffer-sanity.js b/test/parallel/test-http-buffer-sanity.js
index a72d326d6f4107..8dfccf7d5c688d 100644
--- a/test/parallel/test-http-buffer-sanity.js
+++ b/test/parallel/test-http-buffer-sanity.js
@@ -32,16 +32,12 @@ for (let i = 0; i < buffer.length; i++) {
   buffer[i] = i % 256;
 }
 
-
-const web = http.Server(function(req, res) {
-  web.close();
-
-  console.log(req.headers);
+const server = http.Server(function(req, res) {
+  server.close();
 
   let i = 0;
 
-  req.on('data', function(d) {
-    process.stdout.write(',');
+  req.on('data', (d) => {
     measuredSize += d.length;
     for (let j = 0; j < d.length; j++) {
       assert.strictEqual(buffer[i], d[j]);
@@ -49,39 +45,27 @@ const web = http.Server(function(req, res) {
     }
   });
 
-
-  req.on('end', function() {
+  req.on('end', common.mustCall(() => {
+    assert.strictEqual(bufferSize, measuredSize);
     res.writeHead(200);
     res.write('thanks');
     res.end();
-    console.log('response with \'thanks\'');
-  });
-
-  req.connection.on('error', function(e) {
-    console.log(`http server-side error: ${e.message}`);
-    process.exit(1);
-  });
+  }));
 });
 
-web.listen(0, common.mustCall(function() {
-  console.log('Making request');
-
+server.listen(0, common.mustCall(() => {
   const req = http.request({
-    port: this.address().port,
-    method: 'GET',
+    port: server.address().port,
+    method: 'POST',
     path: '/',
     headers: { 'content-length': buffer.length }
-  }, common.mustCall(function(res) {
-    console.log('Got response');
+  }, common.mustCall((res) => {
     res.setEncoding('utf8');
-    res.on('data', common.mustCall(function(string) {
-      assert.strictEqual('thanks', string);
+    let data = '';
+    res.on('data', (chunk) => data += chunk);
+    res.on('end', common.mustCall(() => {
+      assert.strictEqual('thanks', data);
     }));
   }));
   req.end(buffer);
 }));
-
-
-process.on('exit', function() {
-  assert.strictEqual(bufferSize, measuredSize);
-});
diff --git a/test/parallel/test-http-chunked.js b/test/parallel/test-http-chunked.js
index d587141c6df5b1..9ae2932a5c4149 100644
--- a/test/parallel/test-http-chunked.js
+++ b/test/parallel/test-http-chunked.js
@@ -20,7 +20,7 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const http = require('http');
 
@@ -34,31 +34,23 @@ const UTF8_STRING = '南越国是前203年至前111年存在于岭南地区的
                     '采用封建制和郡县制并存的制度，它的建立保证了秦末乱世岭南地区社会秩序的稳定，' +
                     '有效的改善了岭南地区落后的政治、经济现状。';
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   res.writeHead(200, { 'Content-Type': 'text/plain; charset=utf8' });
   res.end(UTF8_STRING, 'utf8');
-});
-server.listen(0, function() {
+}));
+server.listen(0, common.mustCall(() => {
   let data = '';
-  const get = http.get({
+  http.get({
     path: '/',
     host: 'localhost',
-    port: this.address().port
-  }, function(x) {
+    port: server.address().port
+  }, common.mustCall((x) => {
     x.setEncoding('utf8');
-    x.on('data', function(c) { data += c; });
-    x.on('error', function(e) {
-      throw e;
-    });
-    x.on('end', function() {
+    x.on('data', (c) => data += c);
+    x.on('end', common.mustCall(() => {
       assert.strictEqual('string', typeof data);
-      console.log('here is the response:');
       assert.strictEqual(UTF8_STRING, data);
-      console.log(data);
       server.close();
-    });
-  });
-  get.on('error', function(e) { throw e; });
-  get.end();
-
-});
+    }));
+  })).end();
+}));
diff --git a/test/parallel/test-http-client-abort.js b/test/parallel/test-http-client-abort.js
index eaf4a05e6f49f1..71fd2ad64cabdd 100644
--- a/test/parallel/test-http-client-abort.js
+++ b/test/parallel/test-http-client-abort.js
@@ -20,57 +20,35 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
-const assert = require('assert');
+const common = require('../common');
 const http = require('http');
+const Countdown = require('../common/countdown');
 
-let clientAborts = 0;
+const N = 8;
+
+const countdown = new Countdown(N, common.mustCall(() => server.close()));
 
-const server = http.Server(function(req, res) {
-  console.log('Got connection');
+const server = http.Server(common.mustCall((req, res) => {
   res.writeHead(200);
   res.write('Working on it...');
+  req.on('aborted', common.mustCall(() => countdown.dec()));
+}, N));
 
-  // I would expect an error event from req or res that the client aborted
-  // before completing the HTTP request / response cycle, or maybe a new
-  // event like "aborted" or something.
-  req.on('aborted', function() {
-    clientAborts++;
-    console.log(`Got abort ${clientAborts}`);
-    if (clientAborts === N) {
-      console.log('All aborts detected, you win.');
-      server.close();
-    }
-  });
-});
+server.listen(0, common.mustCall(() => {
 
-let responses = 0;
-const N = 8;
-const requests = [];
+  const requests = [];
+  const reqCountdown = new Countdown(N, common.mustCall(() => {
+    requests.forEach((req) => req.abort());
+  }));
 
-server.listen(0, function() {
-  console.log('Server listening.');
+  const options = { port: server.address().port };
 
   for (let i = 0; i < N; i++) {
-    console.log(`Making client ${i}`);
-    const options = { port: this.address().port, path: `/?id=${i}` };
-    const req = http.get(options, function(res) {
-      console.log(`Client response code ${res.statusCode}`);
-
-      res.resume();
-      if (++responses === N) {
-        console.log('All clients connected, destroying.');
-        requests.forEach(function(outReq) {
-          console.log('abort');
-          outReq.abort();
-        });
-      }
-    });
-
-    requests.push(req);
+    options.path = `/?id=${i}`;
+    requests.push(
+      http.get(options, common.mustCall((res) => {
+        res.resume();
+        reqCountdown.dec();
+      })));
   }
-});
-
-process.on('exit', function() {
-  assert.strictEqual(N, clientAborts);
-});
+}));
diff --git a/test/parallel/test-http-client-abort2.js b/test/parallel/test-http-client-abort2.js
index e6804897ea2138..bc4b0e40838b36 100644
--- a/test/parallel/test-http-client-abort2.js
+++ b/test/parallel/test-http-client-abort2.js
@@ -20,18 +20,19 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const http = require('http');
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer(common.mustCall((req, res) => {
   res.end('Hello');
-});
+}));
 
-server.listen(0, function() {
-  const req = http.get({ port: this.address().port }, function(res) {
-    res.on('data', function(data) {
+server.listen(0, common.mustCall(() => {
+  const options = { port: server.address().port };
+  const req = http.get(options, common.mustCall((res) => {
+    res.on('data', (data) => {
       req.abort();
       server.close();
     });
-  });
-});
+  }));
+}));
diff --git a/test/parallel/test-http-client-agent.js b/test/parallel/test-http-client-agent.js
index 1a3c099d4df897..f2d1b612b5af82 100644
--- a/test/parallel/test-http-client-agent.js
+++ b/test/parallel/test-http-client-agent.js
@@ -20,7 +20,7 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const http = require('http');
 
@@ -28,23 +28,22 @@ let name;
 const max = 3;
 let count = 0;
 
-const server = http.Server(function(req, res) {
+const server = http.Server(common.mustCall((req, res) => {
   if (req.url === '/0') {
-    setTimeout(function() {
+    setTimeout(common.mustCall(() => {
       res.writeHead(200);
       res.end('Hello, World!');
-    }, 100);
+    }), 100);
   } else {
     res.writeHead(200);
     res.end('Hello, World!');
   }
-});
-server.listen(0, function() {
-  name = http.globalAgent.getName({ port: this.address().port });
-  for (let i = 0; i < max; ++i) {
+}, max));
+server.listen(0, common.mustCall(() => {
+  name = http.globalAgent.getName({ port: server.address().port });
+  for (let i = 0; i < max; ++i)
     request(i);
-  }
-});
+}));
 
 function request(i) {
   const req = http.get({
@@ -52,7 +51,7 @@ function request(i) {
     path: `/${i}`
   }, function(res) {
     const socket = req.socket;
-    socket.on('close', function() {
+    socket.on('close', common.mustCall(() => {
       ++count;
       if (count < max) {
         assert.strictEqual(http.globalAgent.sockets[name].includes(socket),
@@ -62,11 +61,7 @@ function request(i) {
         assert(!http.globalAgent.requests.hasOwnProperty(name));
         server.close();
       }
-    });
+    }));
     res.resume();
   });
 }
-
-process.on('exit', function() {
-  assert.strictEqual(count, max);
-});
diff --git a/test/parallel/test-http-client-check-http-token.js b/test/parallel/test-http-client-check-http-token.js
index b28af938f9b9ef..4fa3a44802a5f0 100644
--- a/test/parallel/test-http-client-check-http-token.js
+++ b/test/parallel/test-http-client-check-http-token.js
@@ -2,39 +2,28 @@
 const common = require('../common');
 const assert = require('assert');
 const http = require('http');
+const Countdown = require('../common/countdown');
 
 const expectedSuccesses = [undefined, null, 'GET', 'post'];
-let requestCount = 0;
+const expectedFails = [-1, 1, 0, {}, true, false, [], Symbol()];
 
-const server = http.createServer((req, res) => {
-  requestCount++;
-  res.end();
+const countdown =
+  new Countdown(expectedSuccesses.length,
+                common.mustCall(() => server.close()));
 
-  if (expectedSuccesses.length === requestCount) {
-    server.close();
-  }
-}).listen(0, test);
+const server = http.createServer(common.mustCall((req, res) => {
+  res.end();
+  countdown.dec();
+}, expectedSuccesses.length));
 
-function test() {
-  function fail(input) {
+server.listen(0, common.mustCall(() => {
+  expectedFails.forEach((method) => {
     assert.throws(() => {
-      http.request({ method: input, path: '/' }, common.mustNotCall());
+      http.request({ method, path: '/' }, common.mustNotCall());
     }, /^TypeError: Method must be a string$/);
-  }
-
-  fail(-1);
-  fail(1);
-  fail(0);
-  fail({});
-  fail(true);
-  fail(false);
-  fail([]);
-
-  function ok(method) {
-    http.request({ method: method, port: server.address().port }).end();
-  }
+  });
 
   expectedSuccesses.forEach((method) => {
-    ok(method);
+    http.request({ method, port: server.address().port }).end();
   });
-}
+}));
diff --git a/test/parallel/test-http-client-default-headers-exist.js b/test/parallel/test-http-client-default-headers-exist.js
index 05dd509e19e6af..e0cf82e46220c4 100644
--- a/test/parallel/test-http-client-default-headers-exist.js
+++ b/test/parallel/test-http-client-default-headers-exist.js
@@ -20,9 +20,10 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const http = require('http');
+const Countdown = require('../common/countdown');
 
 const expectedHeaders = {
   'DELETE': ['host', 'connection'],
@@ -35,17 +36,18 @@ const expectedHeaders = {
 
 const expectedMethods = Object.keys(expectedHeaders);
 
-let requestCount = 0;
+const countdown =
+  new Countdown(expectedMethods.length,
+                common.mustCall(() => server.close()));
 
-const server = http.createServer(function(req, res) {
-  requestCount++;
+const server = http.createServer(common.mustCall((req, res) => {
   res.end();
 
   assert(expectedHeaders.hasOwnProperty(req.method),
          `${req.method} was an unexpected method`);
 
   const requestHeaders = Object.keys(req.headers);
-  requestHeaders.forEach(function(header) {
+  requestHeaders.forEach((header) => {
     assert.strictEqual(
       expectedHeaders[req.method].includes(header.toLowerCase()),
       true,
@@ -59,15 +61,14 @@ const server = http.createServer(function(req, res) {
     `some headers were missing for method: ${req.method}`
   );
 
-  if (expectedMethods.length === requestCount)
-    server.close();
-});
+  countdown.dec();
+}, expectedMethods.length));
 
-server.listen(0, function() {
-  expectedMethods.forEach(function(method) {
+server.listen(0, common.mustCall(() => {
+  expectedMethods.forEach((method) => {
     http.request({
       method: method,
       port: server.address().port
     }).end();
   });
-});
+}));
diff --git a/test/parallel/test-http-client-encoding.js b/test/parallel/test-http-client-encoding.js
index 8e795481af7289..a4701cdbd0abb1 100644
--- a/test/parallel/test-http-client-encoding.js
+++ b/test/parallel/test-http-client-encoding.js
@@ -20,20 +20,20 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
-
+const common = require('../common');
+const assert = require('assert');
 const http = require('http');
 
-http.createServer(function(req, res) {
-  res.end('ok\n');
-  this.close();
-}).listen(0, test);
-
-function test() {
+const server = http.createServer((req, res) => {
+  res.end('ok');
+  server.close();
+}).listen(0, common.mustCall(() => {
   http.request({
-    port: this.address().port,
+    port: server.address().port,
     encoding: 'utf8'
-  }, function(res) {
-    res.pipe(process.stdout);
-  }).end();
-}
+  }, common.mustCall((res) => {
+    let data = '';
+    res.on('data', (chunk) => data += chunk);
+    res.on('end', common.mustCall(() => assert.strictEqual(data, 'ok')));
+  })).end();
+}));
diff --git a/test/parallel/test-http-client-parse-error.js b/test/parallel/test-http-client-parse-error.js
index 074f24063f5fe4..60f1ee45c8efc1 100644
--- a/test/parallel/test-http-client-parse-error.js
+++ b/test/parallel/test-http-client-parse-error.js
@@ -20,41 +20,33 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
-const assert = require('assert');
-
+const common = require('../common');
 const http = require('http');
 const net = require('net');
+const Countdown = require('../common/countdown');
+
+const countdown = new Countdown(2, common.mustCall(() => server.close()));
 
-let connects = 0;
-let parseErrors = 0;
+const payloads = [
+  'HTTP/1.1 302 Object Moved\r\nContent-Length: 0\r\n\r\nhi world',
+  'bad http = should trigger parse error'
+];
 
 // Create a TCP server
-net.createServer(function(c) {
-  console.log('connection');
-  if (++connects === 1) {
-    c.end('HTTP/1.1 302 Object Moved\r\nContent-Length: 0\r\n\r\nhi world');
-  } else {
-    c.end('bad http - should trigger parse error\r\n');
-    this.close();
-  }
-}).listen(0, '127.0.0.1', function() {
+const server =
+  net.createServer(common.mustCall((c) => c.end(payloads.shift()), 2));
+
+server.listen(0, common.mustCall(() => {
   for (let i = 0; i < 2; i++) {
-    http.request({
-      host: '127.0.0.1',
-      port: this.address().port,
-      method: 'GET',
+    http.get({
+      port: server.address().port,
       path: '/'
-    }).on('error', function(e) {
-      console.log('got error from client');
-      assert.ok(e.message.includes('Parse Error'));
-      assert.strictEqual(e.code, 'HPE_INVALID_CONSTANT');
-      parseErrors++;
-    }).end();
+    }).on('error', common.mustCall((e) => {
+      common.expectsError({
+        code: 'HPE_INVALID_CONSTANT',
+        message: 'Parse Error'
+      })(e);
+      countdown.dec();
+    }));
   }
-});
-
-process.on('exit', function() {
-  assert.strictEqual(connects, 2);
-  assert.strictEqual(parseErrors, 2);
-});
+}));