When Encoding.default_external is set, eg. Rails, ensure RSpec::Core::Bisect::Channel can send and receive binary data (encoded by Marshal.dump)

Author: mikejarema

lib/rspec/core/bisect/utilities.rb

@@ -32,8 +32,13 @@ def publish(event, *args)
       # parent process.
       # @private
       class Channel
+        MARSHAL_DUMP_ENCODING = Marshal.dump("").encoding
+
         def initialize
           @read_io, @write_io = IO.pipe
+
+          # Ensure the pipe is able to send any content produced by Marshal.dump
+          @write_io.set_encoding MARSHAL_DUMP_ENCODING
         end
 
         def send(message)

spec/rspec/core/bisect/utilities_spec.rb

@@ -36,5 +36,39 @@ def foo(notification); end
 
       expect(channel.receive).to eq :value_from_child
     end
+
+    describe "with UTF-8 encoding set (eg. Rails)" do
+      around(:each) do |example|
+        old_external = old_internal = nil
+
+        ignoring_warnings do
+          old_external, Encoding.default_external = Encoding.default_external, Encoding::UTF_8
+          old_internal, Encoding.default_internal = Encoding.default_internal, Encoding::UTF_8
+        end
+
+        example.run
+
+        ignoring_warnings do
+          Encoding.default_external = old_external
+          Encoding.default_internal = old_internal
+        end
+      end
+
+      it "successfully sends binary data" do
+        channel = Bisect::Channel.new
+        expect { channel.send("\xF8") }.not_to raise_error
+      end
+
+      it "supports sending binary data from a child process back to the parent" do
+        channel = Bisect::Channel.new
+
+        in_sub_process do
+          channel.send("\xF8")
+        end
+
+        expect(channel.receive).to eq("\xF8")
+      end
+    end
+
   end
 end