Clarify behaviour of Driver.encode to convert strings to UTF-8 and arrays to ASCII-8BIT

lib/websocket/driver.rb

@@ -115,7 +115,7 @@ module WebSocket
     end
 
     def text(message)
-      message = message.encode(Encoding::UTF_8) unless message.encoding == Encoding::UTF_8
+      message = Driver.encode(message, Encoding::UTF_8)
       frame(message, :text)
     end
 
@@ -194,19 +194,19 @@ module WebSocket
       end
     end
 
-    def self.encode(string, encoding = nil)
-      case string
-        when Array then
-          string = string.pack('C*')
-          encoding ||= Encoding::BINARY
-        when String then
-          encoding ||= string.encoding
+    def self.encode(data, encoding = nil)
+      if Array === data
+        encoding ||= Encoding::BINARY
+        return data.pack('C*').force_encoding(encoding)
       end
-      unless string.encoding == encoding
-        string = string.dup if string.frozen?
-        string.force_encoding(encoding)
-      end
-      string
+
+      encoding ||= Encoding::UTF_8
+
+      return data if data.encoding == encoding
+      return data.encode(encoding) unless data.encoding == Encoding::BINARY
+
+      data = data.dup if data.frozen?
+      data.force_encoding(encoding)
     end
 
     def self.validate_options(options, valid_keys)

spec/spec_helper.rb

@@ -4,10 +4,8 @@ require File.expand_path('../../lib/websocket/driver', __FILE__)
 require File.expand_path('../websocket/driver/draft75_examples', __FILE__)
 
 module EncodingHelper
-  def encode(message)
-    message.respond_to?(:force_encoding) ?
-        message.force_encoding(Encoding::UTF_8) :
-        message
+  def encode(message, encoding = nil)
+    WebSocket::Driver.encode(message, encoding)
   end
 
   def bytes(string)

spec/websocket/driver/client_spec.rb

@@ -230,7 +230,7 @@ describe WebSocket::Driver::Client do
 
     describe "with a valid response followed by a frame" do
       before do
-        resp = response + WebSocket::Driver.encode([0x81, 0x02, 72, 105])
+        resp = response + encode([0x81, 0x02, 72, 105])
         driver.parse(resp)
       end
 

spec/websocket/driver/draft75_examples.rb

@@ -72,7 +72,7 @@ shared_examples_for "draft-75 protocol" do
       end
 
       it "encodes multibyte characters correctly" do
-        message = encode "Apple = "
+        message = encode("Apple = ")
         driver.frame message
         expect(@bytes).to eq [0x00, 0x41, 0x70, 0x70, 0x6c, 0x65, 0x20, 0x3d, 0x20, 0xef, 0xa3, 0xbf, 0xff]
       end

spec/websocket/driver/draft75_spec.rb

@@ -90,7 +90,7 @@ describe WebSocket::Driver::Draft75 do
             "WebSocket-Origin: http://www.example.com\r\n" +
             "WebSocket-Location: ws://www.example.com/socket\r\n" +
             "\r\n")
-        expect(socket).to receive(:write).with(WebSocket::Driver.encode "\x00Hi\xFF", Encoding::BINARY)
+        expect(socket).to receive(:write).with(encode "\x00Hi\xFF".bytes)
 
         driver.frame("Hi")
         driver.start

spec/websocket/driver/draft76_spec.rb

@@ -6,7 +6,7 @@ describe WebSocket::Driver::Draft76 do
   include EncodingHelper
 
   let :body do
-    WebSocket::Driver.encode [0x91, 0x25, 0x3e, 0xd3, 0xa9, 0xe7, 0x6a, 0x88]
+    encode [0x91, 0x25, 0x3e, 0xd3, 0xa9, 0xe7, 0x6a, 0x88]
   end
 
   let :response do
@@ -142,7 +142,7 @@ describe WebSocket::Driver::Draft76 do
             "Sec-WebSocket-Location: ws://www.example.com/socket\r\n" +
             "\r\n")
         expect(socket).to receive(:write).with(response)
-        expect(socket).to receive(:write).with(WebSocket::Driver.encode "\x00Hi\xFF", Encoding::BINARY)
+        expect(socket).to receive(:write).with(encode "\x00Hi\xFF".bytes)
 
         driver.frame("Hi")
         driver.start
@@ -196,7 +196,7 @@ describe WebSocket::Driver::Draft76 do
 
           it "sends any frames queued before the handshake was complete" do
             expect(socket).to receive(:write).with(response)
-            expect(socket).to receive(:write).with(WebSocket::Driver.encode "\x00hello\xFF", Encoding::BINARY)
+            expect(socket).to receive(:write).with(encode "\x00hello\xFF".bytes)
             driver.frame("hello")
             driver.parse(body)
             expect(@bytes).to eq [0, 104, 101, 108, 108, 111, 255]

spec/websocket/driver/hybi_spec.rb

@@ -171,7 +171,7 @@ describe WebSocket::Driver::Hybi do
             "Connection: Upgrade\r\n" +
             "Sec-WebSocket-Accept: JdiiuafpBKRqD7eol0y4vJDTsTs=\r\n" +
             "\r\n")
-        expect(socket).to receive(:write).with(WebSocket::Driver.encode [0x81, 0x02, 72, 105])
+        expect(socket).to receive(:write).with(encode [0x81, 0x02, 72, 105])
 
         driver.frame("Hi")
         driver.start
@@ -195,7 +195,7 @@ describe WebSocket::Driver::Hybi do
             "Connection: Upgrade\r\n" +
             "Sec-WebSocket-Accept: JdiiuafpBKRqD7eol0y4vJDTsTs=\r\n" +
             "\r\n")
-        expect(socket).to receive(:write).with(WebSocket::Driver.encode [0x89, 0])
+        expect(socket).to receive(:write).with(encode [0x89, 0])
 
         driver.ping
         driver.start
@@ -219,7 +219,7 @@ describe WebSocket::Driver::Hybi do
             "Connection: Upgrade\r\n" +
             "Sec-WebSocket-Accept: JdiiuafpBKRqD7eol0y4vJDTsTs=\r\n" +
             "\r\n")
-        expect(socket).to receive(:write).with(WebSocket::Driver.encode [0x8a, 0])
+        expect(socket).to receive(:write).with(encode [0x8a, 0])
 
         driver.pong
         driver.start
@@ -410,7 +410,7 @@ describe WebSocket::Driver::Hybi do
       end
 
       it "encodes multibyte characters correctly" do
-        message = encode "Apple = "
+        message = encode("Apple = ")
         driver.frame message
         expect(@bytes).to eq [0x81, 0x0b, 0x41, 0x70, 0x70, 0x6c, 0x65, 0x20, 0x3d, 0x20, 0xef, 0xa3, 0xbf]
       end