add helpful unit test class.

ivy/ivy.xml

@@ -2,7 +2,7 @@
   <info
     organisation="net.lag"
     module="naggati"
-    revision="0.7"
+    revision="0.7.1"
     e:testclass="net.lag.naggati.TestRunner"
     e:buildpackage="net/lag/naggati"
   />

src/main/scala/net/lag/naggati/Decoder.scala

@@ -16,8 +16,10 @@
 
 package net.lag.naggati
 
+import scala.collection.mutable
 import org.apache.mina.core.buffer.IoBuffer
-import org.apache.mina.core.session.IoSession
+import org.apache.mina.core.filterchain.IoFilter
+import org.apache.mina.core.session.{DummySession, IoSession}
 import org.apache.mina.filter.codec._
 
 
@@ -96,3 +98,26 @@ class Decoder(private val firstStep: Step) extends ProtocolDecoder {
     state.buffer.limit(state.buffer.position)
   }
 }
+
+
+// for use in unit tests
+class TestDecoder(firstStep: Step) {
+  private val fakeDecoderOutput = new ProtocolDecoderOutput {
+    override def flush(nextFilter: IoFilter.NextFilter, s: IoSession) = {}
+    override def write(obj: AnyRef) = written += obj
+  }
+
+  private val fakeSession: IoSession = new DummySession
+  val written = new mutable.ListBuffer[AnyRef]
+  val decoder = new Decoder(firstStep)
+
+  def apply(buffer: IoBuffer): List[AnyRef] = {
+    decoder.decode(fakeSession, buffer, fakeDecoderOutput)
+    written.toList
+  }
+
+  def apply(s: String): List[AnyRef] = apply(s.getBytes)
+  def apply(x: Array[Byte]): List[AnyRef] = apply(IoBuffer.wrap(x))
+
+  def write(obj: AnyRef) = fakeDecoderOutput.write(obj)
+}

src/test/scala/net/lag/naggati/CodecSpec.scala

@@ -59,15 +59,16 @@ object CodecSpec extends Specification {
         End
       }
 
-      val decoder = new Decoder(step)
-      quickDecode(decoder, "xx")
-      written mustEqual Nil
+      val decoder = new TestDecoder(step)
+      decoder("xx") mustEqual Nil
       scored mustEqual false
-      quickDecode(decoder, "y")
-      written mustEqual Nil
+      decoder("y") mustEqual Nil
       scored mustEqual true
     }
 
+
+    // FIXME: convert these other tests to use TestDecoder too.
+
     "read a variable number of bytes" in {
       var n = 2
       var rv: List[String] = Nil