SPIBitBang should mutate params, not pins

lib/denko/spi/bit_bang.rb

@@ -8,16 +8,16 @@ class BitBang
 
       before_initialize do
         # Allow pin aliases.
-        pins[:input]  = pins[:input]  || pins[:poci] || pins[:miso]
-        pins[:output] = pins[:output] || pins[:pico] || pins[:mosi]
-        pins[:clock]  = pins[:clock]  || pins[:sck]  || pins[:clk]
+        params[:input]  = params[:input]  || params[:poci] || params[:miso]
+        params[:output] = params[:output] || params[:pico] || params[:mosi]
+        params[:clock]  = params[:clock]  || params[:sck]  || params[:clk]
 
-        # Clean up the pins hash.
-        [:poci, :miso, :pico, :mosi, :sck, :clk].each { |key| pins.delete(key) }
+        # Clean up the params hash.
+        [:poci, :miso, :pico, :mosi, :sck, :clk].each { |key| params.delete(key) }
 
-        # Validate pins.
-        raise ArgumentError, "either output or input pin required" unless pins[:input] || pins[:output]
-        raise ArgumentError, "clock pin required" unless pins[:clock]
+        # Validate params.
+        raise ArgumentError, "either output or input pin required" unless params[:input] || params[:output]
+        raise ArgumentError, "clock pin required" unless params[:clock]
       end
 
       def initialize_pins(options={})