Native: add Server#bindAsync

packages/grpc-native-core/src/server.js

@@ -954,6 +954,7 @@ Server.prototype.addProtoService = util.deprecate(function(service,
  *     "address:port"
  * @param {grpc.ServerCredentials} creds Server credential object to be used for
  *     SSL. Pass an insecure credentials object for an insecure port.
+ * @return {number} The bound port number. Negative if binding the port failed.
  */
 Server.prototype.bind = function(port, creds) {
   if (this.started) {
@@ -962,4 +963,32 @@ Server.prototype.bind = function(port, creds) {
   return this._server.addHttp2Port(port, creds);
 };
 
+/**
+ * Called with the result of attempting to bind a port
+ * @callback grpc.Server~bindCallback
+ * @param {Error=} error If non-null, indicates that binding the port failed.
+ * @param {number} port The bound port number. If binding the port fails, this
+ *     will be negative to match the output of bind.
+ */
+
+/**
+ * Binds the server to the given port, with SSL disabled if creds is an
+ * insecure credentials object. Provides the result asynchronously.
+ * @param {string} port The port that the server should bind on, in the format
+ *     "address:port"
+ * @param {grpc.ServerCredentials} creds Server credential object to be used for
+ *     SSL. Pass an insecure credentials object for an insecure port.
+ */
+Server.prototype.bindAsync = function(port, creds, callback) {
+  /* This can throw. We do not try to catch that error because it indicates an
+   * incorrect use of the function, which should not be surfaced asynchronously
+   */
+  const result = this.bind(port, creds)
+  if (result < 0) {
+    setImmediate(callback, new Error('Failed to bind port'), result);
+  } else {
+    setImmediate(callback, null, result);
+  }
+}
+
 exports.Server = Server;

packages/grpc-native-core/test/async_test.js

@@ -37,14 +37,16 @@ var getServer = require('./math/math_server.js');
 
 var server = getServer();
 
+let serverCreds = grpc.ServerCredentials.createInsecure();
+
 describe('Async functionality', function() {
   before(function(done) {
-    var port_num = server.bind('0.0.0.0:0',
-                               grpc.ServerCredentials.createInsecure());
-    server.start();
-    math_client = new math.Math('localhost:' + port_num,
-                                grpc.credentials.createInsecure());
-    done();
+    server.bind('0.0.0.0:0', serverCreds, (error, port_num) => {
+      server.start();
+      math_client = new math.Math('localhost:' + port_num,
+                                  grpc.credentials.createInsecure());
+      done();
+    });
   });
   after(function() {
     grpc.closeClient(math_client);