test: add http2 test for method CONNECT

Adds test case for default handling of method CONNECT, as well
as the ability to bind a connect listener and handle the request.

Refs: nodejs#14985

test/parallel/test-http2-compat-method-connect.js

@@ -0,0 +1,41 @@
+// Flags: --expose-http2
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+const assert = require('assert');
+const http2 = require('http2');
+
+const server = http2.createServer(common.mustNotCall());
+
+server.listen(0, common.mustCall(() => testMethodConnect(2)));
+
+server.once('connect', common.mustCall((req, res) => {
+  assert.strictEqual(req.headers[':method'], 'CONNECT');
+  res.statusCode = 405;
+  res.end();
+}));
+
+function testMethodConnect(testsToRun) {
+  if (!testsToRun) {
+    return server.close();
+  }
+
+  const port = server.address().port;
+  const client = http2.connect(`http://localhost:${port}`);
+  const req = client.request({
+    ':method': 'CONNECT',
+    ':authority': `localhost:${port}`
+  });
+
+  req.on('response', common.mustCall((headers) => {
+    assert.strictEqual(headers[':status'], 405);
+  }));
+  req.resume();
+  req.on('end', common.mustCall(() => {
+    client.destroy();
+    testMethodConnect(testsToRun - 1);
+  }));
+  req.end();
+}