Add metadata echo functionality to interop server, and corresponding interop test

2 files changed, 116 insertions, 5 deletions

diff --git a/src/node/interop/interop_client.js b/src/node/interop/interop_client.js
index 8fb8d66920..14ae045275 100644
--- a/src/node/interop/interop_client.js
+++ b/src/node/interop/interop_client.js
@@ -49,6 +49,9 @@ var AUTH_USER = ('155450119199-3psnrh1sdr3d8cpj1v46naggf81mhdnk' +
 var COMPUTE_ENGINE_USER = ('155450119199-r5aaqa2vqoa9g5mv2m6s3m1l293rlmel' +
     '@developer.gserviceaccount.com');
 
+var ECHO_INITIAL_KEY = "x-grpc-test-echo-initial";
+var ECHO_TRAILING_KEY = "x-grpc-test-echo-trailing-bin";
+
 /**
  * Create a buffer filled with size zeroes
  * @param {number} size The length of the buffer
@@ -61,6 +64,27 @@ function zeroBuffer(size) {
 }
 
 /**
+ * This is used for testing functions with multiple asynchronous calls that
+ * can happen in different orders. This should be passed the number of async
+ * function invocations that can occur last, and each of those should call this
+ * function's return value
+ * @param {function()} done The function that should be called when a test is
+ *     complete.
+ * @param {number} count The number of calls to the resulting function if the
+ *     test passes.
+ * @return {function()} The function that should be called at the end of each
+ *     sequence of asynchronous functions.
+ */
+function multiDone(done, count) {
+  return function() {
+    count -= 1;
+    if (count <= 0) {
+      done();
+    }
+  };
+}
+
+/**
  * Run the empty_unary test
  * @param {Client} client The client to test against
  * @param {function} done Callback to call when the test is completed. Included
@@ -271,6 +295,54 @@ function timeoutOnSleepingServer(client, done) {
   });
 }
 
+function customMetadata(client, done) {
+  done = multiDone(done, 5);
+  var metadata = new grpc.Metadata();
+  metadata.set(ECHO_INITIAL_KEY, 'test_initial_metadata_value');
+  metadata.set(ECHO_TRAILING_KEY, new Buffer('ababab', 'hex'));
+  var arg = {
+    response_type: 'COMPRESSABLE',
+    response_size: 314159,
+    payload: {
+      body: zeroBuffer(271828)
+    }
+  };
+  var streaming_arg = {
+    payload: {
+      body: zeroBuffer(271828)
+    }
+  };
+  var unary = client.unaryCall(arg, function(err, resp) {
+    assert.ifError(err);
+    done();
+  }, metadata);
+  unary.on('metadata', function(metadata) {
+    assert.deepEqual(metadata.get(ECHO_INITIAL_KEY),
+                     ['test_initial_metadata_value']);
+    done();
+  });
+  unary.on('status', function(status) {
+    var echo_trailer = status.metadata.get(ECHO_TRAILING_KEY);
+    assert(echo_trailer.length > 0);
+    assert.strictEqual(echo_trailer.toString('hex'), 'ababab');
+    done();
+  });
+  var stream = client.fullDuplexCall(metadata);
+  stream.on('metadata', function(metadata) {
+    assert.deepEqual(metadata.get(ECHO_INITIAL_KEY),
+                     ['test_initial_metadata_value']);
+    done();
+  });
+  stream.on('status', function(status) {
+    var echo_trailer = status.metadata.get(ECHO_TRAILING_KEY);
+    assert(echo_trailer.length > 0);
+    assert.strictEqual(echo_trailer.toString('hex'), 'ababab');
+    done();
+  });
+  stream.write(streaming_arg);
+  stream.end();
+}
+
 /**
  * Run one of the authentication tests.
  * @param {string} expected_user The expected username in the response
@@ -358,6 +430,7 @@ var test_cases = {
   cancel_after_begin: cancelAfterBegin,
   cancel_after_first_response: cancelAfterFirstResponse,
   timeout_on_sleeping_server: timeoutOnSleepingServer,
+  custom_metadata: customMetadata,
   compute_engine_creds: _.partial(authTest, COMPUTE_ENGINE_USER, null),
   service_account_creds: _.partial(authTest, AUTH_USER, AUTH_SCOPE),
   jwt_token_creds: _.partial(authTest, AUTH_USER, null),
diff --git a/src/node/interop/interop_server.js b/src/node/interop/interop_server.js
index 99155e9958..c23f237680 100644
--- a/src/node/interop/interop_server.js
+++ b/src/node/interop/interop_server.js
@@ -39,6 +39,9 @@ var _ = require('lodash');
 var grpc = require('..');
 var testProto = grpc.load(__dirname + '/test.proto').grpc.testing;
 
+var ECHO_INITIAL_KEY = "x-grpc-test-echo-initial";
+var ECHO_TRAILING_KEY = "x-grpc-test-echo-trailing-bin";
+
 /**
  * Create a buffer filled with size zeroes
  * @param {number} size The length of the buffer
@@ -51,6 +54,34 @@ function zeroBuffer(size) {
 }
 
 /**
+ * Echos a header metadata item as specified in the interop spec.
+ * @param {Call} call The call to echo metadata on
+ */
+function echoHeader(call) {
+  var echo_initial = call.metadata.get(ECHO_INITIAL_KEY);
+  if (echo_initial.length > 0) {
+    var response_metadata = new grpc.Metadata();
+    response_metadata.set(ECHO_INITIAL_KEY, echo_initial[0]);
+    call.sendMetadata(response_metadata);
+  }
+}
+
+/**
+ * Gets the trailer metadata that should be echoed when the call is done,
+ * as specified in the interop spec.
+ * @param {Call} call The call to get metadata from
+ * @return {grpc.Metadata} The metadata to send as a trailer
+ */
+function getEchoTrailer(call) {
+  var echo_trailer = call.metadata.get(ECHO_TRAILING_KEY);
+  var response_trailer = new grpc.Metadata();
+  if (echo_trailer.length > 0) {
+    response_trailer.set(ECHO_TRAILING_KEY, echo_trailer[0]);
+  }
+  return response_trailer;
+}
+
+/**
  * Respond to an empty parameter with an empty response.
  * NOTE: this currently does not work due to issue #137
  * @param {Call} call Call to handle
@@ -58,7 +89,8 @@ function zeroBuffer(size) {
  *     or error
  */
 function handleEmpty(call, callback) {
-  callback(null, {});
+  echoHeader(call);
+  callback(null, {}, getEchoTrailer(call));
 }
 
 /**
@@ -68,6 +100,7 @@ function handleEmpty(call, callback) {
  *     error
  */
 function handleUnary(call, callback) {
+  echoHeader(call);
   var req = call.request;
   var zeros = zeroBuffer(req.response_size);
   var payload_type = req.response_type;
@@ -75,7 +108,8 @@ function handleUnary(call, callback) {
     payload_type = ['COMPRESSABLE',
                     'UNCOMPRESSABLE'][Math.random() < 0.5 ? 0 : 1];
   }
-  callback(null, {payload: {type: payload_type, body: zeros}});
+  callback(null, {payload: {type: payload_type, body: zeros}},
+           getEchoTrailer(call));
 }
 
 /**
@@ -85,12 +119,14 @@ function handleUnary(call, callback) {
  *     error
  */
 function handleStreamingInput(call, callback) {
+  echoHeader(call);
   var aggregate_size = 0;
   call.on('data', function(value) {
     aggregate_size += value.payload.body.length;
   });
   call.on('end', function() {
-    callback(null, {aggregated_payload_size: aggregate_size});
+    callback(null, {aggregated_payload_size: aggregate_size},
+             getEchoTrailer(call));
   });
 }
 
@@ -99,6 +135,7 @@ function handleStreamingInput(call, callback) {
  * @param {Call} call Call to handle
  */
 function handleStreamingOutput(call) {
+  echoHeader(call);
   var req = call.request;
   var payload_type = req.response_type;
   if (payload_type === 'RANDOM') {
@@ -113,7 +150,7 @@ function handleStreamingOutput(call) {
       }
     });
   });
-  call.end();
+  call.end(getEchoTrailer(call));
 }
 
 /**
@@ -122,6 +159,7 @@ function handleStreamingOutput(call) {
  * @param {Call} call Call to handle
  */
 function handleFullDuplex(call) {
+  echoHeader(call);
   call.on('data', function(value) {
     var payload_type = value.response_type;
     if (payload_type === 'RANDOM') {
@@ -138,7 +176,7 @@ function handleFullDuplex(call) {
     });
   });
   call.on('end', function() {
-    call.end();
+    call.end(getEchoTrailer(call));
   });
 }