add interaction test with conditions on the mock method's argument: l…

…ist command must print text that contains all available elements

mockitotest/com/vxcompany/spocksnippets/TextConsoleTest.java

@@ -17,13 +17,19 @@
 
 import org.junit.Before;
 import org.junit.Test;
+import org.mockito.ArgumentCaptor;
 
+import java.io.PrintStream;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 
 import static com.vxcompany.spocksnippets.TestUtil.*;
 
+import static org.junit.Assert.assertTrue;
+import static org.mockito.AdditionalMatchers.and;
+import static org.mockito.AdditionalMatchers.find;
+import static org.mockito.Matchers.contains;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 
@@ -34,11 +40,13 @@ public class TextConsoleTest {
 
     private TextConsole console;
     private Game game;
+    private PrintStream output;
 
     @Before
     public void setUp() {
         game = mock(Game.class);
-        console = new TextConsole(game);
+        output = mock(PrintStream.class);
+        console = new TextConsole(game, output);
     }
 
     @Test
@@ -47,4 +55,16 @@ public void textConsole_commandForCombiningTwoAvailableElements_callGameCombine(
         console.eval("combine first with second");
         verify(game).combine(new Element("first"), new Element("second"));
     }
+
+    @Test
+    public void textConsole_listCommand_printAvailableElements() {
+        game.setAvailableElements(createSet(new Element("first"), new Element("second"), new Element("third")));
+        console.eval("list");
+        // for easier test cases we could use argument matchers, but because we have to check
+        // three boolean expressions on the argument, we have to use the more complicated ArgumentCaptor
+        ArgumentCaptor<String> captor = ArgumentCaptor.forClass(String.class);
+        verify(output).println(captor.capture());
+        String text = captor.getValue();
+        assertTrue("list command should print available elements", text.contains("first") && text.contains("second") && text.contains("third"));
+    }
 }

spocktest/com/vxcompany/spocksnippets/TextConsoleSpec.groovy

@@ -26,10 +26,12 @@ class TextConsoleSpec extends Specification {
 
     def console
     def game
+    def output
 
     def setup() {
         game = Mock(Game)
-        console = new TextConsole(game)
+        output = Mock(PrintStream)
+        console = new TextConsole(game, output)
     }
 
     def "on text console, command for combining two available elements should call Game.combine"() {
@@ -40,6 +42,12 @@ class TextConsoleSpec extends Specification {
             1 * game.combine(new Element("first"), new Element("second"))
     }
 
-
+    def "on text console, list command prints available elements"() {
+        when:
+            game.availableElements() >> [new Element("first"), new Element("second"), new Element("third")]
+            console.eval("list")
+        then:
+            1 * output.println({ it.contains("first") && it.contains("second") && it.contains("third") })
+    }
 
 }

src/com/vxcompany/spocksnippets/TextConsole.java

@@ -16,6 +16,7 @@
 // along with SpockSnippets.  If not, see <http://www.gnu.org/licenses/>.
 
 import java.io.InputStream;
+import java.io.PrintStream;
 import java.io.PrintWriter;
 
 /**
@@ -24,9 +25,11 @@
 public class TextConsole {
 
     private Game game;
+    private PrintStream output;
 
-    public TextConsole(Game game) {
+    public TextConsole(Game game, PrintStream output) {
         this.game = game;
+        this.output = output;
     }
 
     public void eval(String userCommand) {