End proxied responses for 1xx, 204, 304 with no body, fix bug where cy server could be proxied (#4358)

* release 3.2.0 [skip ci]

* add failing test for 304

* always end response on 1xx, 204, or 304

* add http req spec

* add test that 1xx, 204, 304 always pass thru immediately

* cleanup

* skip stubborn test

* cleanup, tests

* fix stopping debugproxy where it hasn't been started

fix stopping debugproxy where it hasn't been started

* Never proxy websocket port

* e2e test now works

* unnecesary this

* e2e works in ci


Co-authored-by: Brian Mann <brian.mann86@gmail.com>

packages/https-proxy/lib/server.coffee

@@ -98,13 +98,18 @@ class Server
       res.end()
     .pipe(res)
 
-  _getProxyForUrl: (url) ->
-    if url == "https://localhost:#{@_sniPort}"
+  _getProxyForUrl: (urlStr) ->
+    port = Number(_.get(url.parse(urlStr), 'port'))
+
+    debug('getting proxy URL %o', { port, serverPort: @_port, sniPort: @_sniPort, url: urlStr })
+
+    if [@_sniPort, @_port].includes(port)
       ## https://github.com/cypress-io/cypress/issues/4257
-      ## this is a tunnel to the SNI server, it should never go through a proxy
+      ## this is a tunnel to the SNI server or to the main server,
+      ## it should never go through a proxy
       return undefined
 
-    getProxyForUrl(url)
+    getProxyForUrl(urlStr)
 
   _makeDirectConnection: (req, browserSocket, head) ->
     { port, hostname } = url.parse("https://#{req.url}")
@@ -167,7 +172,7 @@ class Server
       return makeConnection(@_port)
 
     ## else spin up the SNI server
-    { hostname } = url.parse("http://#{req.url}")
+    { hostname } = url.parse("https://#{req.url}")
 
     if sslServer = sslServers[hostname]
       return makeConnection(sslServer.port)