feat: add trailers

lib/https/h2.js

@@ -219,6 +219,9 @@ function requestH2(client, req, res, callback) {
       var newHeaders = {};
       var statusCode = h2Headers[':status'];
       var svrRes = h2Session;
+      svrRes.on('trailers', function(trailers) {
+        svrRes.trailers = trailers;
+      });
       svrRes.statusCode = statusCode;
       // HTTP2 对响应内容格式要求太严格（NGHTTP2_PROTOCOL_ERROR）
       if (!util.hasBody(svrRes, req)) {
@@ -230,7 +233,7 @@ function requestH2(client, req, res, callback) {
       svrRes.httpVersion = '1.1';
       svrRes.headers = newHeaders;
       Object.keys(h2Headers).forEach(function(name) {
-        if (name[0] !== ':') {
+        if (name[0] !== ':' && name !== 'content-length') {
           newHeaders[name] = h2Headers[name];
         }
       });

lib/https/index.js

@@ -781,6 +781,15 @@ function toHttp1(req, res) {
   client.on('error', handleError);
   client.on('response', function(svrRes) {
     svrRes.on('error', handleError);
+    svrRes.once('end', function() {
+      var trailers = svrRes.trailers;
+      if (!util.isEmptyObject(trailers)) {
+        var rawHeaderNames = svrRes.rawTrailers ? getRawHeaderNames(svrRes.rawTrailers) : null;
+        try {
+          res.addTrailers(formatHeaders(trailers, rawHeaderNames));
+        } catch (e) {}
+      }
+    });
     try {
       var code = svrRes.statusCode;
       res.writeHead(code, getStatusMessage(svrRes), formatRawHeaders(svrRes, isH2));