test: clean up http-set-trailers

* remove shared state of request counting from each listener by using callbacks to report test finish. This also fixes slight race condition where one of the request could finish before the other was taken into account resulting in ECONNREFUSED due to premature server.close() * slightly move code for better cohesion * fix error comment in testHttp10 'Trailer ...' -> 'No trailer ...'
lundibundi · Nov 18, 2019 · Nov 18, 2019 · Nov 18, 2019 · 88c5a602ad69b2dde01315bc8ea582c88280d081
commit 88c5a602ad69b2dde01315bc8ea582c88280d081
diff --git a/test/parallel/test-http-set-trailers.js b/test/parallel/test-http-set-trailers.js
@@ -26,91 +26,78 @@ const http = require('http');
 const net = require('net');
 const util = require('util');
 
-let outstanding_reqs = 0;
-
-const server = http.createServer(function(req, res) {
-  res.writeHead(200, [['content-type', 'text/plain']]);
-  res.addTrailers({ 'x-foo': 'bar' });
-  res.end('stuff\n');
-});
-server.listen(0);
-
-
 // First, we test an HTTP/1.0 request.
-server.on('listening', function() {
-  const c = net.createConnection(this.address().port);
-  let res_buffer = '';
+function testHttp10(port, callback) {
+  const c = net.createConnection(port);
 
   c.setEncoding('utf8');
 
-  c.on('connect', function() {
-    outstanding_reqs++;
+  c.on('connect', () => {
     c.write('GET / HTTP/1.0\r\n\r\n');
   });
 
-  c.on('data', function(chunk) {
+  let res_buffer = '';
+  c.on('data', (chunk) => {
     res_buffer += chunk;
   });
 
   c.on('end', function() {
     c.end();
     assert.ok(
       !/x-foo/.test(res_buffer),
-      `Trailer in HTTP/1.0 response. Response buffer: ${res_buffer}`
+      `No trailer in HTTP/1.0 response. Response buffer: ${res_buffer}`
     );
-    outstanding_reqs--;
-    if (outstanding_reqs === 0) {
-      server.close();
-    }
+    callback();
   });
-});
+}
 
 // Now, we test an HTTP/1.1 request.
-server.on('listening', function() {
-  const c = net.createConnection(this.address().port);
-  let res_buffer = '';
-  let tid;
+function testHttp11(port, callback) {
+  const c = net.createConnection(port);
 
   c.setEncoding('utf8');
 
+  let tid;
   c.on('connect', function() {
-    outstanding_reqs++;
     c.write('GET / HTTP/1.1\r\n\r\n');
     tid = setTimeout(common.mustNotCall(), 2000, 'Couldn\'t find last chunk.');
   });
 
+  let res_buffer = '';
   c.on('data', function(chunk) {
     res_buffer += chunk;
     if (/0\r\n/.test(res_buffer)) { // got the end.
-      outstanding_reqs--;
       clearTimeout(tid);
       assert.ok(
         /0\r\nx-foo: bar\r\n\r\n$/.test(res_buffer),
         `No trailer in HTTP/1.1 response. Response buffer: ${res_buffer}`
       );
-      if (outstanding_reqs === 0) {
-        server.close();
-      }
+      callback();
     }
   });
-});
+}
 
 // Now, see if the client sees the trailers.
-server.on('listening', function() {
-  http.get({
-    port: this.address().port,
-    path: '/hello',
-    headers: {}
-  }, function(res) {
+function testClientTrailers(port, callback) {
+  http.get({ port, path: '/hello', headers: {} }, (res) => {
     res.on('end', function() {
       assert.ok('x-foo' in res.trailers,
                 `${util.inspect(res.trailers)} misses the 'x-foo' property`);
-      outstanding_reqs--;
-      if (outstanding_reqs === 0) {
-        server.close();
-      }
+      callback();
     });
     res.resume();
   });
-  outstanding_reqs++;
+}
+
+const server = http.createServer((req, res) => {
+  res.writeHead(200, [['content-type', 'text/plain']]);
+  res.addTrailers({ 'x-foo': 'bar' });
+  res.end('stuff\n');
+});
+server.listen(0, () => {
+  Promise.all([testHttp10, testHttp11, testClientTrailers]
+    .map(util.promisify)
+    .map((f) => f(server.address().port)))
+    .catch((e) => { throw e; })
+    .finally(() => server.close());
 });