Added new Metadata class to abstract over internal representation and normalize keys

src/node/index.js

@@ -41,6 +41,8 @@ var client = require('./src/client.js');
 
 var server = require('./src/server.js');
 
+var Metadata = require('./src/metadata.js');
+
 var grpc = require('bindings')('grpc');
 
 /**
@@ -107,18 +109,12 @@ exports.getGoogleAuthDelegate = function getGoogleAuthDelegate(credential) {
    * @param {function(Error, Object)} callback
    */
   return function updateMetadata(authURI, metadata, callback) {
-    metadata = _.clone(metadata);
-    if (metadata.Authorization) {
-      metadata.Authorization = _.clone(metadata.Authorization);
-    } else {
-      metadata.Authorization = [];
-    }
     credential.getRequestMetadata(authURI, function(err, header) {
       if (err) {
         callback(err);
         return;
       }
-      metadata.Authorization.push(header.Authorization);
+      metadata.add('authorization', header.Authorization);
       callback(null, metadata);
     });
   };
@@ -129,6 +125,11 @@ exports.getGoogleAuthDelegate = function getGoogleAuthDelegate(credential) {
  */
 exports.Server = server.Server;
 
+/**
+ * @see module:src/metadata
+ */
+exports.Metadata = Metadata;
+
 /**
  * Status name to code number mapping
  */

src/node/interop/interop_client.js

@@ -321,13 +321,7 @@ function oauth2Test(expected_user, scope, per_rpc, client, done) {
     credential.getAccessToken(function(err, token) {
       assert.ifError(err);
       var updateMetadata = function(authURI, metadata, callback) {
-        metadata = _.clone(metadata);
-        if (metadata.Authorization) {
-          metadata.Authorization = _.clone(metadata.Authorization);
-        } else {
-          metadata.Authorization = [];
-        }
-        metadata.Authorization.push('Bearer ' + token);
+        metadata.Add('authorization', 'Bearer ' + token);
         callback(null, metadata);
       };
       var makeTestCall = function(error, client_metadata) {

src/node/src/client.js

@@ -42,7 +42,9 @@ var _ = require('lodash');
 
 var grpc = require('bindings')('grpc.node');
 
-var common = require('./common.js');
+var common = require('./common');
+
+var Metadata = require('./metadata');
 
 var EventEmitter = require('events').EventEmitter;
 
@@ -254,8 +256,7 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
    *     serialize
    * @param {function(?Error, value=)} callback The callback to for when the
    *     response is received
-   * @param {array=} metadata Array of metadata key/value pairs to add to the
-   *     call
+   * @param {Metadata=} metadata Metadata to add to the call
    * @param {Object=} options Options map
    * @return {EventEmitter} An event emitter for stream related events
    */
@@ -264,7 +265,9 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
     var emitter = new EventEmitter();
     var call = getCall(this.channel, method, options);
     if (metadata === null || metadata === undefined) {
-      metadata = {};
+      metadata = new Metadata();
+    } else {
+      metadata = metadata.clone();
     }
     emitter.cancel = function cancel() {
       call.cancel();
@@ -281,7 +284,8 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
       var client_batch = {};
       var message = serialize(argument);
       message.grpcWriteFlags = options.flags;
-      client_batch[grpc.opType.SEND_INITIAL_METADATA] = metadata;
+      client_batch[grpc.opType.SEND_INITIAL_METADATA] =
+          metadata._getCoreRepresentation();
       client_batch[grpc.opType.SEND_MESSAGE] = message;
       client_batch[grpc.opType.SEND_CLOSE_FROM_CLIENT] = true;
       client_batch[grpc.opType.RECV_INITIAL_METADATA] = true;
@@ -292,7 +296,8 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
         if (response.status.code !== grpc.status.OK) {
           var error = new Error(response.status.details);
           error.code = response.status.code;
-          error.metadata = response.status.metadata;
+          error.metadata = Metadata._fromCoreRepresentation(
+              response.status.metadata);
           callback(error);
           return;
         } else {
@@ -302,7 +307,8 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
             return;
           }
         }
-        emitter.emit('metadata', response.metadata);
+        emitter.emit('metadata', Metadata._fromCoreRepresentation(
+            response.metadata));
         callback(null, deserialize(response.read));
       });
     });
@@ -326,7 +332,7 @@ function makeClientStreamRequestFunction(method, serialize, deserialize) {
    * @this {Client} Client object. Must have a channel member.
    * @param {function(?Error, value=)} callback The callback to for when the
    *     response is received
-   * @param {array=} metadata Array of metadata key/value pairs to add to the
+   * @param {Metadata=} metadata Array of metadata key/value pairs to add to the
    *     call
    * @param {Object=} options Options map
    * @return {EventEmitter} An event emitter for stream related events
@@ -335,7 +341,9 @@ function makeClientStreamRequestFunction(method, serialize, deserialize) {
     /* jshint validthis: true */
     var call = getCall(this.channel, method, options);
     if (metadata === null || metadata === undefined) {
-      metadata = {};
+      metadata = new Metadata();
+    } else {
+      metadata = metadata.clone();
     }
     var stream = new ClientWritableStream(call, serialize);
     this.updateMetadata(this.auth_uri, metadata, function(error, metadata) {
@@ -345,7 +353,8 @@ function makeClientStreamRequestFunction(method, serialize, deserialize) {
         return;
       }
       var metadata_batch = {};
-      metadata_batch[grpc.opType.SEND_INITIAL_METADATA] = metadata;
+      metadata_batch[grpc.opType.SEND_INITIAL_METADATA] =
+          metadata._getCoreRepresentation();
       metadata_batch[grpc.opType.RECV_INITIAL_METADATA] = true;
       call.startBatch(metadata_batch, function(err, response) {
         if (err) {
@@ -353,7 +362,8 @@ function makeClientStreamRequestFunction(method, serialize, deserialize) {
           // in the other batch.
           return;
         }
-        stream.emit('metadata', response.metadata);
+        stream.emit('metadata', Metadata._fromCoreRepresentation(
+            response.metadata));
       });
       var client_batch = {};
       client_batch[grpc.opType.RECV_MESSAGE] = true;
@@ -363,7 +373,8 @@ function makeClientStreamRequestFunction(method, serialize, deserialize) {
         if (response.status.code !== grpc.status.OK) {
           var error = new Error(response.status.details);
           error.code = response.status.code;
-          error.metadata = response.status.metadata;
+          error.metadata = Metadata._fromCoreRepresentation(
+              response.status.metadata);
           callback(error);
           return;
         } else {
@@ -396,7 +407,7 @@ function makeServerStreamRequestFunction(method, serialize, deserialize) {
    * @this {SurfaceClient} Client object. Must have a channel member.
    * @param {*} argument The argument to the call. Should be serializable with
    *     serialize
-   * @param {array=} metadata Array of metadata key/value pairs to add to the
+   * @param {Metadata=} metadata Array of metadata key/value pairs to add to the
    *     call
    * @param {Object} options Options map
    * @return {EventEmitter} An event emitter for stream related events
@@ -405,7 +416,9 @@ function makeServerStreamRequestFunction(method, serialize, deserialize) {
     /* jshint validthis: true */
     var call = getCall(this.channel, method, options);
     if (metadata === null || metadata === undefined) {
-      metadata = {};
+      metadata = new Metadata();
+    } else {
+      metadata = metadata.clone();
     }
     var stream = new ClientReadableStream(call, deserialize);
     this.updateMetadata(this.auth_uri, metadata, function(error, metadata) {
@@ -417,7 +430,8 @@ function makeServerStreamRequestFunction(method, serialize, deserialize) {
       var start_batch = {};
       var message = serialize(argument);
       message.grpcWriteFlags = options.flags;
-      start_batch[grpc.opType.SEND_INITIAL_METADATA] = metadata;
+      start_batch[grpc.opType.SEND_INITIAL_METADATA] =
+          metadata._getCoreRepresentation();
       start_batch[grpc.opType.RECV_INITIAL_METADATA] = true;
       start_batch[grpc.opType.SEND_MESSAGE] = message;
       start_batch[grpc.opType.SEND_CLOSE_FROM_CLIENT] = true;
@@ -427,7 +441,8 @@ function makeServerStreamRequestFunction(method, serialize, deserialize) {
           // in the other batch.
           return;
         }
-        stream.emit('metadata', response.metadata);
+        stream.emit('metadata', Metadata._fromCoreRepresentation(
+            response.metadata));
       });
       var status_batch = {};
       status_batch[grpc.opType.RECV_STATUS_ON_CLIENT] = true;
@@ -436,7 +451,8 @@ function makeServerStreamRequestFunction(method, serialize, deserialize) {
         if (response.status.code !== grpc.status.OK) {
           var error = new Error(response.status.details);
           error.code = response.status.code;
-          error.metadata = response.status.metadata;
+          error.metadata = Metadata._fromCoreRepresentation(
+              response.status.metadata);
           stream.emit('error', error);
           return;
         } else {
@@ -466,7 +482,7 @@ function makeBidiStreamRequestFunction(method, serialize, deserialize) {
   /**
    * Make a bidirectional stream request with this method on the given channel.
    * @this {SurfaceClient} Client object. Must have a channel member.
-   * @param {array=} metadata Array of metadata key/value pairs to add to the
+   * @param {Metadata=} metadata Array of metadata key/value pairs to add to the
    *     call
    * @param {Options} options Options map
    * @return {EventEmitter} An event emitter for stream related events
@@ -475,7 +491,9 @@ function makeBidiStreamRequestFunction(method, serialize, deserialize) {
     /* jshint validthis: true */
     var call = getCall(this.channel, method, options);
     if (metadata === null || metadata === undefined) {
-      metadata = {};
+      metadata = new Metadata();
+    } else {
+      metadata = metadata.clone();
     }
     var stream = new ClientDuplexStream(call, serialize, deserialize);
     this.updateMetadata(this.auth_uri, metadata, function(error, metadata) {
@@ -485,7 +503,8 @@ function makeBidiStreamRequestFunction(method, serialize, deserialize) {
         return;
       }
       var start_batch = {};
-      start_batch[grpc.opType.SEND_INITIAL_METADATA] = metadata;
+      start_batch[grpc.opType.SEND_INITIAL_METADATA] =
+          metadata._getCoreRepresentation();
       start_batch[grpc.opType.RECV_INITIAL_METADATA] = true;
       call.startBatch(start_batch, function(err, response) {
         if (err) {
@@ -493,7 +512,8 @@ function makeBidiStreamRequestFunction(method, serialize, deserialize) {
           // in the other batch.
           return;
         }
-        stream.emit('metadata', response.metadata);
+        stream.emit('metadata', Metadata._fromCoreRepresentation(
+            response.metadata));
       });
       var status_batch = {};
       status_batch[grpc.opType.RECV_STATUS_ON_CLIENT] = true;
@@ -502,7 +522,8 @@ function makeBidiStreamRequestFunction(method, serialize, deserialize) {
         if (response.status.code !== grpc.status.OK) {
           var error = new Error(response.status.details);
           error.code = response.status.code;
-          error.metadata = response.status.metadata;
+          error.metadata = Metadata._fromCoreRepresentation(
+              response.status.metadata);
           stream.emit('error', error);
           return;
         } else {

src/node/src/metadata.js

@@ -0,0 +1,167 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/**
+ * Metadata module
+ * @module
+ */
+
+'use strict';
+
+var _ = require('lodash');
+
+/**
+ * Class for storing metadata. Keys are normalized to lowercase ASCII.
+ * @constructor
+ */
+function Metadata() {
+  this._internal_repr = {};
+}
+
+function normalizeKey(key) {
+  return _.deburr(key).toLowerCase();
+}
+
+function validate(key, value) {
+  if (_.endsWith(key, '-bin')) {
+    if (!(value instanceof Buffer)) {
+      throw new Error('keys that end with \'-bin\' must have Buffer values');
+    }
+  } else {
+    if (!_.isString(value)) {
+      throw new Error(
+          'keys that don\'t end with \'-bin\' must have String values');
+    }
+  }
+}
+
+/**
+ * Sets the given value for the given key, replacing any other values associated
+ * with that key. Normalizes the key.
+ * @param {String} key The key to set
+ * @param {String|Buffer} value The value to set. Must be a buffer if and only
+ *     if the normalized key ends with '-bin'
+ */
+Metadata.prototype.set = function(key, value) {
+  key = normalizeKey(key);
+  validate(key, value);
+  this._internal_repr[key] = [value];
+};
+
+/**
+ * Adds the given value for the given key. Normalizes the key.
+ * @param {String} key The key to add to.
+ * @param {String|Buffer} value The value to add. Must be a buffer if and only
+ *     if the normalized key ends with '-bin'
+ */
+Metadata.prototype.add = function(key, value) {
+  key = normalizeKey(key);
+  validate(key, value);
+  if (!this._internal_repr[key]) {
+    this._internal_repr[key] = [];
+  }
+  this._internal_repr[key].push(value);
+};
+
+/**
+ * Remove the given key and any associated values.
+ * @param {String} key The key to remove
+ */
+Metadata.prototype.remove = function(key) {
+  if (Object.prototype.hasOwnProperty.call(this._internal_repr, key)) {
+    delete this._internal_repr[key];
+  }
+};
+
+/**
+ * Gets a list of all values associated with the key.
+ * @param {String} key The key to get
+ * @return {Array.<String|Buffer>} The values associated with that key
+ */
+Metadata.prototype.get = function(key) {
+  if (Object.prototype.hasOwnProperty.call(this._internal_repr, key)) {
+    return this._internal_repr[key];
+  } else {
+    return [];
+  }
+};
+
+/**
+ * Get a map of each key to a single associated value. This reflects the most
+ * common way that people will want to see metadata.
+ * @return {Object.<String,String|Buffer>} A key/value mapping of the metadata
+ */
+Metadata.prototype.getMap = function() {
+  var result = {};
+  _.forOwn(this._internal_repr, function(values, key) {
+    if(values.length > 0) {
+      result[key] = values[0];
+    }
+  });
+  return result;
+};
+
+/**
+ * Clone the metadata object.
+ * @return {Metadata} The new cloned object
+ */
+Metadata.prototype.clone = function() {
+  var copy = new Metadata();
+  copy._internal_repr = _.cloneDeep(this._internal_repr);
+  return copy;
+}
+
+/**
+ * Gets the metadata in the format used by interal code. Intended for internal
+ * use only. API stability is not guaranteed.
+ * @private
+ * @return {Object.<String, Array.<String|Buffer>>} The metadata
+ */
+Metadata.prototype._getCoreRepresentation = function() {
+  return this._internal_repr;
+};
+
+/**
+ * Creates a Metadata object from a metadata map in the internal format.
+ * Intended for internal use only. API stability is not guaranteed.
+ * @private
+ * @param {Object.<String, Array.<String|Buffer>>} The metadata
+ * @return {Metadata} The new Metadata object
+ */
+Metadata._fromCoreRepresentation = function(metadata) {
+  var newMetadata = new Metadata();
+  newMetadata._internal_repr = _.cloneDeep(metadata);
+  return newMetadata;
+};
+
+module.exports = Metadata;

src/node/src/server.js

@@ -44,6 +44,8 @@ var grpc = require('bindings')('grpc.node');
 
 var common = require('./common');
 
+var Metadata = require('./metadata');
+
 var stream = require('stream');
 
 var Readable = stream.Readable;
@@ -60,10 +62,10 @@ var EventEmitter = require('events').EventEmitter;
  * @param {Object} error The error object
  */
 function handleError(call, error) {
+  var statusMetadata = new Metadata();
   var status = {
     code: grpc.status.UNKNOWN,
-    details: 'Unknown Error',
-    metadata: {}
+    details: 'Unknown Error'
   };
   if (error.hasOwnProperty('message')) {
     status.details = error.message;
@@ -75,11 +77,13 @@ function handleError(call, error) {
     }
   }
   if (error.hasOwnProperty('metadata')) {
-    status.metadata = error.metadata;
+    statusMetadata = error.metadata;
   }
+  status.metadata = statusMetadata._getCoreRepresentation();
   var error_batch = {};
   if (!call.metadataSent) {
-    error_batch[grpc.opType.SEND_INITIAL_METADATA] = {};
+    error_batch[grpc.opType.SEND_INITIAL_METADATA] =
+        (new Metadata())._getCoreRepresentation();
   }
   error_batch[grpc.opType.SEND_STATUS_FROM_SERVER] = status;
   call.startBatch(error_batch, function(){});
@@ -114,22 +118,24 @@ function waitForCancel(call, emitter) {
  * @param {*} value The value to respond with
  * @param {function(*):Buffer=} serialize Serialization function for the
  *     response
- * @param {Object=} metadata Optional trailing metadata to send with status
+ * @param {Metadata=} metadata Optional trailing metadata to send with status
  * @param {number=} flags Flags for modifying how the message is sent.
  *     Defaults to 0.
  */
 function sendUnaryResponse(call, value, serialize, metadata, flags) {
   var end_batch = {};
+  var statusMetadata = new Metadata();
   var status = {
     code: grpc.status.OK,
-    details: 'OK',
-    metadata: {}
+    details: 'OK'
   };
   if (metadata) {
-    status.metadata = metadata;
+    statusMetadata = metadata;
   }
+  status.metadata = statusMetadata._getCoreRepresentation();
   if (!call.metadataSent) {
-    end_batch[grpc.opType.SEND_INITIAL_METADATA] = {};
+    end_batch[grpc.opType.SEND_INITIAL_METADATA] =
+        (new Metadata())._getCoreRepresentation();
     call.metadataSent = true;
   }
   var message = serialize(value);
@@ -151,15 +157,17 @@ function setUpWritable(stream, serialize) {
   stream.status = {
     code : grpc.status.OK,
     details : 'OK',
-    metadata : {}
+    metadata : new Metadata()
   };
   stream.serialize = common.wrapIgnoreNull(serialize);
   function sendStatus() {
     var batch = {};
     if (!stream.call.metadataSent) {
       stream.call.metadataSent = true;
-      batch[grpc.opType.SEND_INITIAL_METADATA] = {};
+      batch[grpc.opType.SEND_INITIAL_METADATA] =
+          (new Metadata())._getCoreRepresentation();
     }
+    stream.status.metadata = stream.status.metadata._getCoreRepresentation();
     batch[grpc.opType.SEND_STATUS_FROM_SERVER] = stream.status;
     stream.call.startBatch(batch, function(){});
   }
@@ -203,7 +211,7 @@ function setUpWritable(stream, serialize) {
   /**
    * Override of Writable#end method that allows for sending metadata with a
    * success status.
-   * @param {Object=} metadata Metadata to send with the status
+   * @param {Metadata=} metadata Metadata to send with the status
    */
   stream.end = function(metadata) {
     if (metadata) {
@@ -266,7 +274,8 @@ function _write(chunk, encoding, callback) {
   /* jshint validthis: true */
   var batch = {};
   if (!this.call.metadataSent) {
-    batch[grpc.opType.SEND_INITIAL_METADATA] = {};
+    batch[grpc.opType.SEND_INITIAL_METADATA] =
+        (new Metadata())._getCoreRepresentation();
     this.call.metadataSent = true;
   }
   var message = this.serialize(chunk);
@@ -289,15 +298,15 @@ ServerWritableStream.prototype._write = _write;
 
 /**
  * Send the initial metadata for a writable stream.
- * @param {Object<String, Array<(String|Buffer)>>} responseMetadata Metadata
- *   to send
+ * @param {Metadata} responseMetadata Metadata to send
  */
 function sendMetadata(responseMetadata) {
   /* jshint validthis: true */
   if (!this.call.metadataSent) {
     this.call.metadataSent = true;
     var batch = [];
-    batch[grpc.opType.SEND_INITIAL_METADATA] = responseMetadata;
+    batch[grpc.opType.SEND_INITIAL_METADATA] =
+        responseMetadata._getCoreRepresentation();
     this.call.startBatch(batch, function(err) {
       if (err) {
         this.emit('error', err);
@@ -422,7 +431,7 @@ ServerDuplexStream.prototype.getPeer = getPeer;
  * @access private
  * @param {grpc.Call} call The call to handle
  * @param {Object} handler Request handler object for the method that was called
- * @param {Object} metadata Metadata from the client
+ * @param {Metadata} metadata Metadata from the client
  */
 function handleUnary(call, handler, metadata) {
   var emitter = new EventEmitter();
@@ -430,7 +439,8 @@ function handleUnary(call, handler, metadata) {
     if (!call.metadataSent) {
       call.metadataSent = true;
       var batch = {};
-      batch[grpc.opType.SEND_INITIAL_METADATA] = responseMetadata;
+      batch[grpc.opType.SEND_INITIAL_METADATA] =
+          responseMetadata._getCoreRepresentation();
       call.startBatch(batch, function() {});
     }
   };
@@ -478,7 +488,7 @@ function handleUnary(call, handler, metadata) {
  * @access private
  * @param {grpc.Call} call The call to handle
  * @param {Object} handler Request handler object for the method that was called
- * @param {Object} metadata Metadata from the client
+ * @param {Metadata} metadata Metadata from the client
  */
 function handleServerStreaming(call, handler, metadata) {
   var stream = new ServerWritableStream(call, handler.serialize);
@@ -507,7 +517,7 @@ function handleServerStreaming(call, handler, metadata) {
  * @access private
  * @param {grpc.Call} call The call to handle
  * @param {Object} handler Request handler object for the method that was called
- * @param {Object} metadata Metadata from the client
+ * @param {Metadata} metadata Metadata from the client
  */
 function handleClientStreaming(call, handler, metadata) {
   var stream = new ServerReadableStream(call, handler.deserialize);
@@ -515,7 +525,8 @@ function handleClientStreaming(call, handler, metadata) {
     if (!call.metadataSent) {
       call.metadataSent = true;
       var batch = {};
-      batch[grpc.opType.SEND_INITIAL_METADATA] = responseMetadata;
+      batch[grpc.opType.SEND_INITIAL_METADATA] =
+          responseMetadata._getCoreRepresentation();
       call.startBatch(batch, function() {});
     }
   };
@@ -542,7 +553,7 @@ function handleClientStreaming(call, handler, metadata) {
  * @access private
  * @param {grpc.Call} call The call to handle
  * @param {Object} handler Request handler object for the method that was called
- * @param {Object} metadata Metadata from the client
+ * @param {Metadata} metadata Metadata from the client
  */
 function handleBidiStreaming(call, handler, metadata) {
   var stream = new ServerDuplexStream(call, handler.serialize,
@@ -599,7 +610,7 @@ function Server(options) {
       var details = event.new_call;
       var call = details.call;
       var method = details.method;
-      var metadata = details.metadata;
+      var metadata = Metadata._fromCoreRepresentation(details.metadata);
       if (method === null) {
         return;
       }
@@ -609,7 +620,8 @@ function Server(options) {
         handler = handlers[method];
       } else {
         var batch = {};
-        batch[grpc.opType.SEND_INITIAL_METADATA] = {};
+        batch[grpc.opType.SEND_INITIAL_METADATA] =
+            (new Metadata())._getCoreRepresentation();
         batch[grpc.opType.SEND_STATUS_FROM_SERVER] = {
           code: grpc.status.UNIMPLEMENTED,
           details: 'This method is not available on this server.',

src/node/test/health_test.js

@@ -39,7 +39,7 @@ var health = require('../health_check/health.js');
 
 var grpc = require('../');
 
-describe('Health Checking', function() {
+describe.only('Health Checking', function() {
   var statusMap = {
     '': {
       '': 'SERVING',

src/node/test/metadata_test.js

@@ -0,0 +1,172 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+'use strict';
+
+var Metadata = require('../src/metadata.js');
+
+var assert = require('assert');
+
+describe('Metadata', function() {
+  var metadata;
+  beforeEach(function() {
+    metadata = new Metadata();
+  });
+  describe('#set', function() {
+    it('Only accepts string values for non "-bin" keys', function() {
+      assert.throws(function() {
+        metadata.set('key', new Buffer('value'));
+      });
+      assert.doesNotThrow(function() {
+        metadata.set('key', 'value');
+      });
+    });
+    it('Only accepts Buffer values for "-bin" keys', function() {
+      assert.throws(function() {
+        metadata.set('key-bin', 'value');
+      });
+      assert.doesNotThrow(function() {
+        metadata.set('key-bin', new Buffer('value'));
+      });
+    });
+    it('Saves values that can be retrieved', function() {
+      metadata.set('key', 'value');
+      assert.deepEqual(metadata.get('key'), ['value']);
+    });
+    it('Overwrites previous values', function() {
+      metadata.set('key', 'value1');
+      metadata.set('key', 'value2');
+      assert.deepEqual(metadata.get('key'), ['value2']);
+    });
+    it('Normalizes keys', function() {
+      metadata.set('Key', 'value1');
+      assert.deepEqual(metadata.get('key'), ['value1']);
+      metadata.set('KEY', 'value2');
+      assert.deepEqual(metadata.get('key'), ['value2']);
+    });
+  });
+  describe('#add', function() {
+    it('Only accepts string values for non "-bin" keys', function() {
+      assert.throws(function() {
+        metadata.add('key', new Buffer('value'));
+      });
+      assert.doesNotThrow(function() {
+        metadata.add('key', 'value');
+      });
+    });
+    it('Only accepts Buffer values for "-bin" keys', function() {
+      assert.throws(function() {
+        metadata.add('key-bin', 'value');
+      });
+      assert.doesNotThrow(function() {
+        metadata.add('key-bin', new Buffer('value'));
+      });
+    });
+    it('Saves values that can be retrieved', function() {
+      metadata.add('key', 'value');
+      assert.deepEqual(metadata.get('key'), ['value']);
+    });
+    it('Combines with previous values', function() {
+      metadata.add('key', 'value1');
+      metadata.add('key', 'value2');
+      assert.deepEqual(metadata.get('key'), ['value1', 'value2']);
+    });
+    it('Normalizes keys', function() {
+      metadata.add('Key', 'value1');
+      assert.deepEqual(metadata.get('key'), ['value1']);
+      metadata.add('KEY', 'value2');
+      assert.deepEqual(metadata.get('key'), ['value1', 'value2']);
+    });
+  });
+  describe('#remove', function() {
+    it('clears values from a key', function() {
+      metadata.add('key', 'value');
+      metadata.remove('key');
+      assert.deepEqual(metadata.get('key'), []);
+    });
+    it('does not normalize keys', function() {
+      metadata.add('key', 'value');
+      metadata.remove('KEY');
+      assert.deepEqual(metadata.get('key'), ['value']);
+    });
+  });
+  describe('#get', function() {
+    beforeEach(function() {
+      metadata.add('key', 'value1');
+      metadata.add('key', 'value2');
+      metadata.add('key-bin', new Buffer('value'));
+    });
+    it('gets all values associated with a key', function() {
+      assert.deepEqual(metadata.get('key'), ['value1', 'value2']);
+    });
+    it('does not normalize keys', function() {
+      assert.deepEqual(metadata.get('KEY'), []);
+    });
+    it('returns an empty list for non-existent keys', function() {
+      assert.deepEqual(metadata.get('non-existent-key'), []);
+    });
+    it('returns Buffers for "-bin" keys', function() {
+      assert(metadata.get('key-bin')[0] instanceof Buffer);
+    });
+  });
+  describe('#getMap', function() {
+    it('gets a map of keys to values', function() {
+      metadata.add('key1', 'value1');
+      metadata.add('Key2', 'value2');
+      metadata.add('KEY3', 'value3');
+      assert.deepEqual(metadata.getMap(),
+                       {key1: 'value1',
+                        key2: 'value2',
+                        key3: 'value3'});
+    });
+  });
+  describe('#clone', function() {
+    it('retains values from the original', function() {
+      metadata.add('key', 'value');
+      var copy = metadata.clone();
+      assert.deepEqual(copy.get('key'), ['value']);
+    });
+    it('Does not see newly added values', function() {
+      metadata.add('key', 'value1');
+      var copy = metadata.clone();
+      metadata.add('key', 'value2');
+      assert.deepEqual(copy.get('key'), ['value1']);
+    });
+    it('Does not add new values to the original', function() {
+      metadata.add('key', 'value1');
+      var copy = metadata.clone();
+      copy.add('key', 'value2');
+      assert.deepEqual(metadata.get('key'), ['value1']);
+    });
+  });
+});

src/node/test/surface_test.js

@@ -262,6 +262,7 @@ describe('Generic client and server', function() {
 describe('Echo metadata', function() {
   var client;
   var server;
+  var metadata;
   before(function() {
     var test_proto = ProtoBuf.loadProtoFile(__dirname + '/test_service.proto');
     var test_service = test_proto.lookup('TestService');
@@ -294,6 +295,8 @@ describe('Echo metadata', function() {
     var Client = surface_client.makeProtobufClientConstructor(test_service);
     client = new Client('localhost:' + port, grpc.Credentials.createInsecure());
     server.start();
+    metadata = new grpc.Metadata();
+    metadata.set('key', 'value');
   });
   after(function() {
     server.shutdown();
@@ -301,35 +304,35 @@ describe('Echo metadata', function() {
   it('with unary call', function(done) {
     var call = client.unary({}, function(err, data) {
       assert.ifError(err);
-    }, {key: ['value']});
+    }, metadata);
     call.on('metadata', function(metadata) {
-      assert.deepEqual(metadata.key, ['value']);
+      assert.deepEqual(metadata.get('key'), ['value']);
       done();
     });
   });
   it('with client stream call', function(done) {
     var call = client.clientStream(function(err, data) {
       assert.ifError(err);
-    }, {key: ['value']});
+    }, metadata);
     call.on('metadata', function(metadata) {
-      assert.deepEqual(metadata.key, ['value']);
+      assert.deepEqual(metadata.get('key'), ['value']);
       done();
     });
     call.end();
   });
   it('with server stream call', function(done) {
-    var call = client.serverStream({}, {key: ['value']});
+    var call = client.serverStream({}, metadata);
     call.on('data', function() {});
     call.on('metadata', function(metadata) {
-      assert.deepEqual(metadata.key, ['value']);
+      assert.deepEqual(metadata.get('key'), ['value']);
       done();
     });
   });
   it('with bidi stream call', function(done) {
-    var call = client.bidiStream({key: ['value']});
+    var call = client.bidiStream(metadata);
     call.on('data', function() {});
     call.on('metadata', function(metadata) {
-      assert.deepEqual(metadata.key, ['value']);
+      assert.deepEqual(metadata.get('key'), ['value']);
       done();
     });
     call.end();
@@ -337,9 +340,10 @@ describe('Echo metadata', function() {
   it('shows the correct user-agent string', function(done) {
     var version = require('../package.json').version;
     var call = client.unary({}, function(err, data) { assert.ifError(err); },
-                            {key: ['value']});
+                            metadata);
     call.on('metadata', function(metadata) {
-      assert(_.startsWith(metadata['user-agent'], 'grpc-node/' + version));
+      assert(_.startsWith(metadata.get('user-agent')[0],
+                          'grpc-node/' + version));
       done();
     });
   });
@@ -354,13 +358,14 @@ describe('Other conditions', function() {
     var test_proto = ProtoBuf.loadProtoFile(__dirname + '/test_service.proto');
     test_service = test_proto.lookup('TestService');
     server = new grpc.Server();
+    var trailer_metadata = new grpc.Metadata();
     server.addProtoService(test_service, {
       unary: function(call, cb) {
         var req = call.request;
         if (req.error) {
-          cb(new Error('Requested error'), null, {trailer_present: ['yes']});
+          cb(new Error('Requested error'), null, trailer_metadata);
         } else {
-          cb(null, {count: 1}, {trailer_present: ['yes']});
+          cb(null, {count: 1}, trailer_metadata);
         }
       },
       clientStream: function(stream, cb){
@@ -369,14 +374,14 @@ describe('Other conditions', function() {
         stream.on('data', function(data) {
           if (data.error) {
             errored = true;
-            cb(new Error('Requested error'), null, {trailer_present: ['yes']});
+            cb(new Error('Requested error'), null, trailer_metadata);
           } else {
             count += 1;
           }
         });
         stream.on('end', function() {
           if (!errored) {
-            cb(null, {count: count}, {trailer_present: ['yes']});
+            cb(null, {count: count}, trailer_metadata);
           }
         });
       },
@@ -384,13 +389,13 @@ describe('Other conditions', function() {
         var req = stream.request;
         if (req.error) {
           var err = new Error('Requested error');
-          err.metadata = {trailer_present: ['yes']};
+          err.metadata = trailer_metadata;
           stream.emit('error', err);
         } else {
           for (var i = 0; i < 5; i++) {
             stream.write({count: i});
           }
-          stream.end({trailer_present: ['yes']});
+          stream.end(trailer_metadata);
         }
       },
       bidiStream: function(stream) {
@@ -398,10 +403,8 @@ describe('Other conditions', function() {
         stream.on('data', function(data) {
           if (data.error) {
             var err = new Error('Requested error');
-            err.metadata = {
-              trailer_present: ['yes'],
-              count: ['' + count]
-            };
+            err.metadata = trailer_metadata.clone();
+            err.metadata.add('count', '' + count);
             stream.emit('error', err);
           } else {
             stream.write({count: count});
@@ -409,7 +412,7 @@ describe('Other conditions', function() {
           }
         });
         stream.on('end', function() {
-          stream.end({trailer_present: ['yes']});
+          stream.end(trailer_metadata);
         });
       }
     });
@@ -510,7 +513,7 @@ describe('Other conditions', function() {
         assert.ifError(err);
       });
       call.on('status', function(status) {
-        assert.deepEqual(status.metadata.trailer_present, ['yes']);
+        assert.deepEqual(status.metadata.get('trailer_present'), ['yes']);
         done();
       });
     });
@@ -519,7 +522,7 @@ describe('Other conditions', function() {
         assert(err);
       });
       call.on('status', function(status) {
-        assert.deepEqual(status.metadata.trailer_present, ['yes']);
+        assert.deepEqual(status.metadata.get('trailer_present'), ['yes']);
         done();
       });
     });
@@ -531,7 +534,7 @@ describe('Other conditions', function() {
       call.write({error: false});
       call.end();
       call.on('status', function(status) {
-        assert.deepEqual(status.metadata.trailer_present, ['yes']);
+        assert.deepEqual(status.metadata.get('trailer_present'), ['yes']);
         done();
       });
     });
@@ -543,7 +546,7 @@ describe('Other conditions', function() {
       call.write({error: true});
       call.end();
       call.on('status', function(status) {
-        assert.deepEqual(status.metadata.trailer_present, ['yes']);
+        assert.deepEqual(status.metadata.get('trailer_present'), ['yes']);
         done();
       });
     });
@@ -552,7 +555,7 @@ describe('Other conditions', function() {
       call.on('data', function(){});
       call.on('status', function(status) {
         assert.strictEqual(status.code, grpc.status.OK);
-        assert.deepEqual(status.metadata.trailer_present, ['yes']);
+        assert.deepEqual(status.metadata.get('trailer_present'), ['yes']);
         done();
       });
     });
@@ -560,7 +563,7 @@ describe('Other conditions', function() {
       var call = client.serverStream({error: true});
       call.on('data', function(){});
       call.on('error', function(error) {
-        assert.deepEqual(error.metadata.trailer_present, ['yes']);
+        assert.deepEqual(error.metadata.get('trailer_present'), ['yes']);
         done();
       });
     });
@@ -572,7 +575,7 @@ describe('Other conditions', function() {
       call.on('data', function(){});
       call.on('status', function(status) {
         assert.strictEqual(status.code, grpc.status.OK);
-        assert.deepEqual(status.metadata.trailer_present, ['yes']);
+        assert.deepEqual(status.metadata.get('trailer_present'), ['yes']);
         done();
       });
     });
@@ -583,7 +586,7 @@ describe('Other conditions', function() {
       call.end();
       call.on('data', function(){});
       call.on('error', function(error) {
-        assert.deepEqual(error.metadata.trailer_present, ['yes']);
+        assert.deepEqual(error.metadata.get('trailer_present'), ['yes']);
         done();
       });
     });