Propagate grpc backend status to frontend

javascript/net/grpc/web/clientreadablestream.js

@@ -16,8 +16,6 @@ goog.require('goog.net.XhrIo');
 goog.require('goog.net.streams.NodeReadableStream');
 goog.require('goog.net.streams.createXhrNodeReadableStream');
 goog.require('jspb.Message');
-goog.require('proto.google.rpc.Status');
-goog.require('proto.grpc.gateway.Pair');
 
 
 /**
@@ -28,10 +26,11 @@ goog.require('proto.grpc.gateway.Pair');
  * @final
  * @param {!goog.net.XhrIo} xhr The XhrIo object
  * @param {function(?):!jspb.Message} deserializeFunc
+ * @param {function(!string):!Object} parseRpcStatusFunc
  *   The deserialize function for the proto
  */
 grpc.web.ClientReadableStream = function(
-    xhr, deserializeFunc) {
+    xhr, deserializeFunc, parseRpcStatusFunc) {
   /**
    * @private
    * @type {?goog.net.streams.NodeReadableStream} The XHR Node Readable
@@ -57,6 +56,12 @@ grpc.web.ClientReadableStream = function(
    * @type {function(!Object)|null} The trailing metadata callback
    */
   this.onStatusCallback_ = null;
+
+  /**
+   * @private
+   * @type {function(!string):!Object} A function to parse the Rpc Status response
+   */
+  this.parseRpcStatusFunc_ = parseRpcStatusFunc;
 };
 
 
@@ -74,33 +79,13 @@ grpc.web.ClientReadableStream.prototype.on = function(
   if (eventType == 'data') {
     this.xhrNodeReadableStream_.on('data', function(data) {
       if ('1' in data) {
-        var base64_message = data['1'];
+        var response = self.deserializeFunc_(data['1']);
-        var response = self.deserializeFunc_(base64_message);
         callback(response);
       }
-      if ('2' in data) {
+      if ('2' in data && self.onStatusCallback_) {
-        var base64_message = data['2'];
+        var status = self.parseRpcStatusFunc_(data['2']);
-        var _status =
-          proto.google.rpc.Status.deserializeBinary(base64_message);
-        var status = {};
-        var metadata = {};
-        status['code'] = _status.getCode();
-        status['details'] = _status.getMessage();
-        var details = _status.getDetailsList();
-        for (var i = 0; i < details.length; i++) {
-          var pair = proto.grpc.gateway.Pair.deserializeBinary(
-              details[i].getValue());
-          var first = new TextDecoder("utf-8").decode(
-              /** @type {!ArrayBufferView|undefined} */ (pair.getFirst_asU8()));
-          var second = new TextDecoder("utf-8").decode(
-              /** @type {!ArrayBufferView|undefined} */ (pair.getSecond_asU8()));
-          metadata[first] = second;
-        }
-        status['metadata'] = metadata;
-        if (self.onStatusCallback_) {
         self.onStatusCallback_(status);
       }
-      }
     });
   } else if (eventType == 'status') {
     this.onStatusCallback_ = callback;
@@ -108,6 +93,7 @@ grpc.web.ClientReadableStream.prototype.on = function(
   return this;
 };
 
+
 /**
  * Close the stream.
  */

javascript/net/grpc/web/gatewayclientbase.js

@@ -8,9 +8,13 @@
 goog.provide('grpc.web.GatewayClientBase');
 
 
+goog.require('goog.crypt');
 goog.require('goog.crypt.base64');
 goog.require('goog.net.XhrIo');
 goog.require('grpc.web.ClientReadableStream');
+goog.require('grpc.web.Status');
+goog.require('proto.google.rpc.Status');
+goog.require('proto.grpc.gateway.Pair');
 
 
 
@@ -40,7 +44,7 @@ grpc.web.GatewayClientBase.prototype.serialize_ = function(request) {
  * @param {!Object<string, string>} metadata User defined call metadata
  * @param {function(?):!jspb.Message} deserializeFunc
  *   The deserialize function for the proto
- * @param {function(?string, ?Object=)} callback A callback
+ * @param {function(?Object=, ?Object=)} callback A callback
  * function which takes (error, response)
  * @return {!grpc.web.ClientReadableStream|undefined} The Client Readable
  *   Stream
@@ -55,8 +59,16 @@ grpc.web.GatewayClientBase.prototype.rpcCall = function(
   var stream = this.getClientReadableStream_(xhr, deserializeFunc);
 
   stream.on('data', function(response) {
-    var err = null; // TODO: propagate error
+    callback(null, response);
-    callback(err, response);
+  });
+
+  stream.on('status', function(status) {
+    if (status.code != grpc.web.Status.StatusCode.OK) {
+      callback({
+        'code': status.code,
+        'message': status.details
+      }, null);
+    }
   });
 
   xhr.headers.set('Content-Type', 'application/x-protobuf');
@@ -110,5 +122,34 @@ grpc.web.GatewayClientBase.prototype.newXhr_ = function() {
  */
 grpc.web.GatewayClientBase.prototype.getClientReadableStream_ = function(
     xhr, deserializeFunc) {
-  return new grpc.web.ClientReadableStream(xhr, deserializeFunc);
+  return new grpc.web.ClientReadableStream(xhr, deserializeFunc,
+    grpc.web.GatewayClientBase.parseRpcStatusFunc_);
+};
+
+
+/**
+ * @private
+ * @static
+ * @param {!string} data Data returned from underlying stream
+ * @return {!Object} status The Rpc Status details
+ */
+grpc.web.GatewayClientBase.parseRpcStatusFunc_ = function(data) {
+  var rpcStatus =
+    proto.google.rpc.Status.deserializeBinary(data);
+  var status = {};
+  var metadata = {};
+  status['code'] = rpcStatus.getCode();
+  status['details'] = rpcStatus.getMessage();
+  var details = rpcStatus.getDetailsList();
+  for (var i = 0; i < details.length; i++) {
+    var pair = proto.grpc.gateway.Pair.deserializeBinary(
+      details[i].getValue());
+    var first = goog.crypt.utf8ByteArrayToString(
+      pair.getFirst_asU8());
+    var second = goog.crypt.utf8ByteArrayToString(
+      pair.getSecond_asU8());
+    metadata[first] = second;
+  }
+  status['metadata'] = metadata;
+  return status;
 };

javascript/net/grpc/web/grpc_generator.cc

@@ -168,7 +168,7 @@ void PrintUnaryCall(Printer* printer, std::map<string, string> vars) {
       " *     request proto\n"
       " * @param {!Object<string, string>} metadata User defined\n"
       " *     call metadata\n"
-      " * @param {function(?string, ?Object=)} callback "
+      " * @param {function(?Object=, ?Object=)} callback "
       "The callback\n"
       " *     function(error, response)\n"
       " * @return {!grpc.web.ClientReadableStream|undefined} The XHR Node\n"

javascript/net/grpc/web/status.js

@@ -0,0 +1,162 @@
+/**
+ * @fileoverview gRPC Web Status codes and mapping.
+ *
+ * gRPC Web Status codes and mapping.
+ *
+ * @author stanleycheung@google.com (Stanley Cheung)
+ */
+goog.provide('grpc.web.Status');
+
+
+/**
+ * gRPC Status Codes
+ * See: https://github.com/grpc/grpc/blob/master/include/grpc%2B%2B/impl/codegen/status_code_enum.h
+ * @enum {int}
+ */
+grpc.web.Status.StatusCode = {
+  // Not an error; returned on success.
+  OK: 0,
+
+  // The operation was cancelled (typically by the caller).
+  CANCELLED: 1,
+
+  // Unknown error. An example of where this error may be returned is if a
+  // Status value received from another address space belongs to an error-space
+  // that is not known in this address space. Also errors raised by APIs that
+  // do not return enough error information may be converted to this error.
+  UNKNOWN: 2,
+
+  // Client specified an invalid argument. Note that this differs from
+  // FAILED_PRECONDITION. INVALID_ARGUMENT indicates arguments that are
+  // problematic regardless of the state of the system (e.g., a malformed file
+  // name).
+  INVALID_ARGUMENT: 3,
+
+  // Deadline expired before operation could complete. For operations that
+  // change the state of the system, this error may be returned even if the
+  // operation has completed successfully. For example, a successful response
+  // from a server could have been delayed long enough for the deadline to
+  // expire.
+  DEADLINE_EXCEEDED: 4,
+
+  // Some requested entity (e.g., file or directory) was not found.
+  NOT_FOUND: 5,
+
+  // Some entity that we attempted to create (e.g., file or directory) already
+  // exists.
+  ALREADY_EXISTS: 6,
+
+  // The caller does not have permission to execute the specified operation.
+  // PERMISSION_DENIED must not be used for rejections caused by exhausting
+  // some resource (use RESOURCE_EXHAUSTED instead for those errors).
+  // PERMISSION_DENIED must not be used if the caller can not be identified
+  // (use UNAUTHENTICATED instead for those errors).
+  PERMISSION_DENIED: 7,
+
+  // The request does not have valid authentication credentials for the
+  // operation.
+  UNAUTHENTICATED: 16,
+
+  // Some resource has been exhausted, perhaps a per-user quota, or perhaps the
+  // entire file system is out of space.
+  RESOURCE_EXHAUSTED: 8,
+
+  // Operation was rejected because the system is not in a state required for
+  // the operation's execution. For example, directory to be deleted may be
+  // non-empty, an rmdir operation is applied to a non-directory, etc.
+  //
+  // A litmus test that may help a service implementor in deciding
+  // between FAILED_PRECONDITION, ABORTED, and UNAVAILABLE:
+  //  (a) Use UNAVAILABLE if the client can retry just the failing call.
+  //  (b) Use ABORTED if the client should retry at a higher-level
+  //      (e.g., restarting a read-modify-write sequence).
+  //  (c) Use FAILED_PRECONDITION if the client should not retry until
+  //      the system state has been explicitly fixed. E.g., if an "rmdir"
+  //      fails because the directory is non-empty, FAILED_PRECONDITION
+  //      should be returned since the client should not retry unless
+  //      they have first fixed up the directory by deleting files from it.
+  //  (d) Use FAILED_PRECONDITION if the client performs conditional
+  //      REST Get/Update/Delete on a resource and the resource on the
+  //      server does not match the condition. E.g., conflicting
+  //      read-modify-write on the same resource.
+  FAILED_PRECONDITION: 9,
+
+  // The operation was aborted, typically due to a concurrency issue like
+  // sequencer check failures, transaction aborts, etc.
+  //
+  // See litmus test above for deciding between FAILED_PRECONDITION, ABORTED,
+  // and UNAVAILABLE.
+  ABORTED: 10,
+
+  // Operation was attempted past the valid range. E.g., seeking or reading
+  // past end of file.
+  //
+  // Unlike INVALID_ARGUMENT, this error indicates a problem that may be fixed
+  // if the system state changes. For example, a 32-bit file system will
+  // generate INVALID_ARGUMENT if asked to read at an offset that is not in the
+  // range [0,2^32-1], but it will generate OUT_OF_RANGE if asked to read from
+  // an offset past the current file size.
+  //
+  // There is a fair bit of overlap between FAILED_PRECONDITION and
+  // OUT_OF_RANGE. We recommend using OUT_OF_RANGE (the more specific error)
+  // when it applies so that callers who are iterating through a space can
+  // easily look for an OUT_OF_RANGE error to detect when they are done.
+  OUT_OF_RANGE: 11,
+
+  // Operation is not implemented or not supported/enabled in this service.
+  UNIMPLEMENTED: 12,
+
+  // Internal errors. Means some invariants expected by underlying System has
+  // been broken. If you see one of these errors, Something is very broken.
+  INTERNAL: 13,
+
+  // The service is currently unavailable. This is a most likely a transient
+  // condition and may be corrected by retrying with a backoff.
+  //
+  // See litmus test above for deciding between FAILED_PRECONDITION, ABORTED,
+  // and UNAVAILABLE.
+  UNAVAILABLE: 14,
+
+  // Unrecoverable data loss or corruption.
+  DATA_LOSS: 15,
+};
+
+
+/**
+ * Convert HTTP Status code to gRPC Status code
+ * @param {int} http_status HTTP Status Code
+ * @return {int} gRPC Status Code
+ */
+grpc.web.Status.HttpStatusToGrpcStatus = function(http_status) {
+  switch (http_status) {
+    case 200:
+      return grpc.web.Status.StatusCode.OK;
+    case 400:
+      return grpc.web.Status.StatusCode.INVALID_ARGUMENT;
+    case 401:
+      return grpc.web.Status.StatusCode.UNAUTHENTICATED;
+    case 403:
+      return grpc.web.Status.StatusCode.PERMISSION_DENIED;
+    case 404:
+      return grpc.web.Status.StatusCode.NOT_FOUND;
+    case 409:
+      return grpc.web.Status.StatusCode.ABORTED;
+    case 412:
+      return grpc.web.Status.StatusCode.FAILED_PRECONDITION;
+    case 429:
+      return grpc.web.Status.StatusCode.RESOURCE_EXHAUSTED;
+    case 499:
+      return grpc.web.Status.StatusCode.CANCELLED;
+    case 500:
+      return grpc.web.Status.StatusCode.UNKNOWN;
+    case 501:
+      return grpc.web.Status.StatusCode.UNIMPLEMENTED;
+    case 503:
+      return grpc.web.Status.StatusCode.UNAVAILABLE;
+    case 504:
+      return grpc.web.Status.StatusCode.DEADLINE_EXCEEDED;
+    /* everything else is unknown */
+    default:
+      return grpc.web.Status.StatusCode.UNKNOWN;
+  }
+};

net/grpc/gateway/examples/echo/echotest.html

@@ -32,9 +32,13 @@
    var unaryRequest = new proto.grpc.gateway.testing.EchoRequest();
    unaryRequest.setMessage(msg);
    echoService.Echo(unaryRequest, {}, function(err, response) {
+     if (err) {
+       addRightMessage('Error code: '+err.code+' "'+err.message+'"');
+     } else {
        setTimeout(function () {
          addRightMessage(response.getMessage());
        }, INTERVAL);
+     }
    });
  };
 
@@ -51,6 +55,11 @@
    stream.on('data', function(response) {
      addRightMessage(response.getMessage());
    });
+   stream.on('status', function(status) {
+     if (status.code != grpc.web.Status.StatusCode.OK) {
+       addRightMessage('Error code: '+status.code+' "'+status.details+'"');
+     }
+   });
  };
 
  var send = function(e) {