add ruby subclasses of bad status for each GPRC status code

src/ruby/lib/grpc/errors.rb

@@ -35,6 +35,13 @@ module GRPC
   # either end of a GRPC connection.  When raised, it indicates that a status
   # error should be returned to the other end of a GRPC connection; when
   # caught it means that this end received a status error.
+  #
+  # There is also subclass of BadStatus in this module for each GRPC status.
+  # E.g., the GRPC::Cancelled class corresponds to status CANCELLED.
+  #
+  # See
+  # https://github.com/grpc/grpc/blob/master/include/grpc/impl/codegen/status.h
+  # for detailed descriptions of each status code.
   class BadStatus < StandardError
     attr_reader :code, :details, :metadata
 
@@ -57,7 +64,122 @@ module GRPC
     end
   end
 
-  # Cancelled is an exception class that indicates that an rpc was cancelled.
-  class Cancelled < StandardError
+  # GRPC status code corresponding to status OK
+  class Ok < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::OK, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status CANCELLED
+  class Cancelled < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::CANCELLED, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status UNKNOWN
+  class Unknown < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::UNKNOWN, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status INVALID_ARGUMENT
+  class InvalidArgument < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::INVALID_ARGUMENT, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status DEADLINE_EXCEEDED
+  class DeadlineExceeded < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::DEADLINE_EXCEEDED, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status NOT_FOUND
+  class NotFound < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::NOT_FOUND, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status ALREADY_EXISTS
+  class AlreadyExists < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::ALREADY_EXISTS, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status PERMISSION_DENIED
+  class PermissionDenied < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::PERMISSION_DENIED, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status UNAUTHENTICATED
+  class Unauthenticated < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::UNAUTHENTICATED, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status RESOURCE_EXHAUSTED
+  class ResourceExhausted < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::RESOURCE_EXHAUSTED, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status FAILED_PRECONDITION
+  class FailedPrecondition < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::FAILED_PRECONDITION, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status ABORTED
+  class Aborted < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::ABORTED, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status OUT_OF_RANGE
+  class OutOfRange < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::OUT_OF_RANGE, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status UNIMPLEMENTED
+  class Unimplemented < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::UNIMPLEMENTED, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status INTERNAL
+  class Internal < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::INTERNAL, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status UNAVAILABLE
+  class Unavailable < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::UNAVAILABLE, details, metadata)
+    end
+  end
+
+  # GRPC status code corresponding to status DATA_LOSS
+  class DataLoss < BadStatus
+    def initialize(details = 'unknown cause', metadata = {})
+      super(Core::StatusCodes::DATA_LOSS, details, metadata)
+    end
   end
 end

src/ruby/spec/error_sanity_spec.rb

@@ -0,0 +1,58 @@
+# 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.
+
+require 'grpc'
+
+StatusCodes = GRPC::Core::StatusCodes
+
+describe StatusCodes do
+  # convert upper snake-case to camel case.
+  # e.g., DEADLINE_EXCEEDED -> DeadlineExceeded
+  def upper_snake_to_camel(name)
+    name.to_s.split('_').map(&:downcase).map(&:capitalize).join('')
+  end
+
+  StatusCodes.constants.each do |status_name|
+    it 'there is a subclass of BadStatus corresponding to StatusCode: ' \
+      "#{name} that has code: #{StatusCodes.const_get(status_name)}" do
+      camel_case = upper_snake_to_camel(status_name)
+      error_class = GRPC.const_get(camel_case)
+      # expect the error class to be a subclass of BadStatus
+      expect(error_class < GRPC::BadStatus)
+
+      error_object = error_class.new
+      # check that the code matches the int value of the error's constant
+      expect(error_object.code).to eq(StatusCodes.const_get(status_name))
+
+      # check default parameters
+      expect(error_object.details).to eq('unknown cause')
+      expect(error_object.metadata).to eq({})
+    end
+  end
+end