Adding parameterized specification (Issue#1055) (#1088)

* Resolution proposition to Issue#1055 (UML diagram left to do)

* Deciding not to modify the UML diagram for now

specification/src/main/java/com/iluwatar/specification/app/App.java

@@ -31,8 +31,11 @@ import com.iluwatar.specification.creature.Octopus;
 import com.iluwatar.specification.creature.Shark;
 import com.iluwatar.specification.creature.Troll;
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.selector.ColorSelector;
+import com.iluwatar.specification.selector.MassGreaterThanSelector;
+import com.iluwatar.specification.selector.MassSmallerThanOrEqSelector;
 import com.iluwatar.specification.selector.MovementSelector;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -51,7 +54,7 @@ import org.slf4j.LoggerFactory;
  * <p>http://martinfowler.com/apsupp/spec.pdf</p>
  */
 public class App {
-  
+
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
   /**
@@ -61,6 +64,8 @@ public class App {
     // initialize creatures list
     List<Creature> creatures = List.of(new Goblin(), new Octopus(), new Dragon(), new Shark(),
         new Troll(), new KillerBee());
+    // so-called "hard-coded" specification
+    LOGGER.info("Demonstrating hard-coded specification :");
     // find all walking creatures
     LOGGER.info("Find all walking creatures");
     List<Creature> walkingCreatures =
@@ -79,5 +84,19 @@ public class App {
             .filter(new ColorSelector(Color.RED).and(new MovementSelector(Movement.FLYING)))
             .collect(Collectors.toList());
     redAndFlyingCreatures.forEach(c -> LOGGER.info(c.toString()));
+    // so-called "parameterized" specification
+    LOGGER.info("Demonstrating parameterized specification :");
+    // find all creatures heavier than 500kg
+    LOGGER.info("Find all creatures heavier than 600kg");
+    List<Creature> heavyCreatures =
+        creatures.stream().filter(new MassGreaterThanSelector(600.0))
+            .collect(Collectors.toList());
+    heavyCreatures.forEach(c -> LOGGER.info(c.toString()));
+    // find all creatures heavier than 500kg
+    LOGGER.info("Find all creatures lighter than or weighing exactly 500kg");
+    List<Creature> lightCreatures =
+        creatures.stream().filter(new MassSmallerThanOrEqSelector(500.0))
+            .collect(Collectors.toList());
+    lightCreatures.forEach(c -> LOGGER.info(c.toString()));
   }
 }

specification/src/main/java/com/iluwatar/specification/creature/AbstractCreature.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 
@@ -36,20 +37,23 @@ public abstract class AbstractCreature implements Creature {
   private Size size;
   private Movement movement;
   private Color color;
+  private Mass mass;
 
   /**
    * Constructor.
    */
-  public AbstractCreature(String name, Size size, Movement movement, Color color) {
+  public AbstractCreature(String name, Size size, Movement movement, Color color, Mass mass) {
     this.name = name;
     this.size = size;
     this.movement = movement;
     this.color = color;
+    this.mass = mass;
   }
 
   @Override
   public String toString() {
-    return String.format("%s [size=%s, movement=%s, color=%s]", name, size, movement, color);
+    return String.format("%s [size=%s, movement=%s, color=%s, mass=%s]",
+        name, size, movement, color, mass);
   }
 
   @Override
@@ -71,4 +75,9 @@ public abstract class AbstractCreature implements Creature {
   public Color getColor() {
     return color;
   }
+
+  @Override
+  public Mass getMass() {
+    return mass;
+  }
 }

specification/src/main/java/com/iluwatar/specification/creature/Creature.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 
@@ -39,4 +40,6 @@ public interface Creature {
   Movement getMovement();
 
   Color getColor();
+
+  Mass getMass();
 }

specification/src/main/java/com/iluwatar/specification/creature/Dragon.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 
@@ -33,6 +34,10 @@ import com.iluwatar.specification.property.Size;
 public class Dragon extends AbstractCreature {
 
   public Dragon() {
-    super("Dragon", Size.LARGE, Movement.FLYING, Color.RED);
+    this(new Mass(39300.0));
+  }
+
+  public Dragon(Mass mass) {
+    super("Dragon", Size.LARGE, Movement.FLYING, Color.RED, mass);
   }
 }

specification/src/main/java/com/iluwatar/specification/creature/Goblin.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 
@@ -33,6 +34,10 @@ import com.iluwatar.specification.property.Size;
 public class Goblin extends AbstractCreature {
 
   public Goblin() {
-    super("Goblin", Size.SMALL, Movement.WALKING, Color.GREEN);
+    this(new Mass(30.0));
+  }
+
+  public Goblin(Mass mass) {
+    super("Goblin", Size.SMALL, Movement.WALKING, Color.GREEN, mass);
   }
 }

specification/src/main/java/com/iluwatar/specification/creature/KillerBee.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 
@@ -33,6 +34,10 @@ import com.iluwatar.specification.property.Size;
 public class KillerBee extends AbstractCreature {
 
   public KillerBee() {
-    super("KillerBee", Size.SMALL, Movement.FLYING, Color.LIGHT);
+    this(new Mass(6.7));
+  }
+
+  public KillerBee(Mass mass) {
+    super("KillerBee", Size.SMALL, Movement.FLYING, Color.LIGHT, mass);
   }
 }

specification/src/main/java/com/iluwatar/specification/creature/Octopus.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 
@@ -33,6 +34,10 @@ import com.iluwatar.specification.property.Size;
 public class Octopus extends AbstractCreature {
 
   public Octopus() {
-    super("Octopus", Size.NORMAL, Movement.SWIMMING, Color.DARK);
+    this(new Mass(12.0));
+  }
+
+  public Octopus(Mass mass) {
+    super("Octopus", Size.NORMAL, Movement.SWIMMING, Color.DARK, mass);
   }
 }

specification/src/main/java/com/iluwatar/specification/creature/Shark.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 
@@ -33,6 +34,10 @@ import com.iluwatar.specification.property.Size;
 public class Shark extends AbstractCreature {
 
   public Shark() {
-    super("Shark", Size.NORMAL, Movement.SWIMMING, Color.LIGHT);
+    this(new Mass(500.0));
+  }
+
+  public Shark(Mass mass) {
+    super("Shark", Size.NORMAL, Movement.SWIMMING, Color.LIGHT, mass);
   }
 }

specification/src/main/java/com/iluwatar/specification/creature/Troll.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 
@@ -33,6 +34,10 @@ import com.iluwatar.specification.property.Size;
 public class Troll extends AbstractCreature {
 
   public Troll() {
-    super("Troll", Size.LARGE, Movement.WALKING, Color.DARK);
+    this(new Mass(4000.0));
+  }
+
+  public Troll(Mass mass) {
+    super("Troll", Size.LARGE, Movement.WALKING, Color.DARK, mass);
   }
 }

specification/src/main/java/com/iluwatar/specification/property/Color.java

@@ -24,7 +24,7 @@
 package com.iluwatar.specification.property;
 
 /**
- * <p>Color property.</p>
+ * Color property.
  */
 public enum Color {
 

specification/src/main/java/com/iluwatar/specification/property/Mass.java

@@ -0,0 +1,65 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.specification.property;
+
+/** Mass property. */
+public class Mass {
+
+  private double value;
+  private String title;
+
+  public Mass(double value) {
+    this.value = value;
+    this.title = value + "kg"; // Implicit call to Double.toString(value)
+  }
+
+  public final boolean greaterThan(Mass other) {
+    return this.value > other.value;
+  }
+
+  public final boolean smallerThan(Mass other) {
+    return this.value < other.value;
+  }
+
+  public final boolean greaterThanOrEq(Mass other) {
+    return this.value >= other.value;
+  }
+
+  public final boolean smallerThanOrEq(Mass other) {
+    return this.value <= other.value;
+  }
+
+  @Override
+  public String toString() {
+    return title;
+  }
+
+  @Override
+  public final boolean equals(Object obj) {
+    if (!(obj instanceof Mass)) {
+      return false;
+    }
+    return ((Mass) obj).value == this.value;
+  }
+}

specification/src/main/java/com/iluwatar/specification/selector/MassGreaterThanSelector.java

@@ -0,0 +1,44 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.specification.selector;
+
+import com.iluwatar.specification.creature.Creature;
+import com.iluwatar.specification.property.Mass;
+import java.util.function.Predicate;
+
+/** Mass selector for values greater than the parameter. */
+public class MassGreaterThanSelector implements Predicate<Creature> {
+
+  private final Mass mass;
+
+  /** The use of a double as a parameter will spare some typing when instantiating this class. */
+  public MassGreaterThanSelector(double mass) {
+    this.mass = new Mass(mass);
+  }
+
+  @Override
+  public boolean test(Creature t) {
+    return t.getMass().greaterThan(mass);
+  }
+}

specification/src/main/java/com/iluwatar/specification/selector/MassSmallerThanOrEqSelector.java

@@ -0,0 +1,44 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.specification.selector;
+
+import com.iluwatar.specification.creature.Creature;
+import com.iluwatar.specification.property.Mass;
+import java.util.function.Predicate;
+
+/** Mass selector for values smaller or equal to the parameter. */
+public class MassSmallerThanOrEqSelector implements Predicate<Creature> {
+
+  private final Mass mass;
+
+  /** The use of a double as a parameter will spare some typing when instantiating this class. */
+  public MassSmallerThanOrEqSelector(double mass) {
+    this.mass = new Mass(mass);
+  }
+
+  @Override
+  public boolean test(Creature t) {
+    return t.getMass().smallerThanOrEq(mass);
+  }
+}

specification/src/test/java/com/iluwatar/specification/creature/CreatureTest.java

@@ -24,6 +24,7 @@
 package com.iluwatar.specification.creature;
 
 import com.iluwatar.specification.property.Color;
+import com.iluwatar.specification.property.Mass;
 import com.iluwatar.specification.property.Movement;
 import com.iluwatar.specification.property.Size;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -47,12 +48,12 @@ public class CreatureTest {
    */
   public static Collection<Object[]> dataProvider() {
     return List.of(
-            new Object[]{new Dragon(), "Dragon", Size.LARGE, Movement.FLYING, Color.RED},
-            new Object[]{new Goblin(), "Goblin", Size.SMALL, Movement.WALKING, Color.GREEN},
-            new Object[]{new KillerBee(), "KillerBee", Size.SMALL, Movement.FLYING, Color.LIGHT},
-            new Object[]{new Octopus(), "Octopus", Size.NORMAL, Movement.SWIMMING, Color.DARK},
-            new Object[]{new Shark(), "Shark", Size.NORMAL, Movement.SWIMMING, Color.LIGHT},
-            new Object[]{new Troll(), "Troll", Size.LARGE, Movement.WALKING, Color.DARK}
+            new Object[]{new Dragon(), "Dragon", Size.LARGE, Movement.FLYING, Color.RED, new Mass(39300.0)},
+            new Object[]{new Goblin(), "Goblin", Size.SMALL, Movement.WALKING, Color.GREEN, new Mass(30.0)},
+            new Object[]{new KillerBee(), "KillerBee", Size.SMALL, Movement.FLYING, Color.LIGHT, new Mass(6.7)},
+            new Object[]{new Octopus(), "Octopus", Size.NORMAL, Movement.SWIMMING, Color.DARK, new Mass(12.0)},
+            new Object[]{new Shark(), "Shark", Size.NORMAL, Movement.SWIMMING, Color.LIGHT, new Mass(500.0)},
+            new Object[]{new Troll(), "Troll", Size.LARGE, Movement.WALKING, Color.DARK, new Mass(4000.0)}
     );
   }
 
@@ -82,11 +83,17 @@ public class CreatureTest {
 
   @ParameterizedTest
   @MethodSource("dataProvider")
-  public void testToString(Creature testedCreature, String name, Size size, Movement movement, Color color) {
+  public void testGetMass(Creature testedCreature, String name, Size size, Movement movement, Color color, Mass mass) {
+    assertEquals(mass, testedCreature.getMass());
+  }
+
+  @ParameterizedTest
+  @MethodSource("dataProvider")
+  public void testToString(Creature testedCreature, String name, Size size, Movement movement, Color color, Mass mass) {
     final String toString = testedCreature.toString();
     assertNotNull(toString);
     assertEquals(
-            String.format("%s [size=%s, movement=%s, color=%s]", name, size, movement, color),
+            String.format("%s [size=%s, movement=%s, color=%s, mass=%s]", name, size, movement, color, mass),
             toString
     );
   }

specification/src/test/java/com/iluwatar/specification/selector/MassSelectorTest.java

@@ -0,0 +1,50 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.specification.selector;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.iluwatar.specification.creature.Creature;
+import com.iluwatar.specification.property.Mass;
+import org.junit.jupiter.api.Test;
+
+public class MassSelectorTest {
+
+  /** Verify if the mass selector gives the correct results */
+  @Test
+  public void testMass() {
+    final Creature lightCreature = mock(Creature.class);
+    when(lightCreature.getMass()).thenReturn(new Mass(50.0));
+
+    final Creature heavyCreature = mock(Creature.class);
+    when(heavyCreature.getMass()).thenReturn(new Mass(2500.0));
+
+    final MassSmallerThanOrEqSelector lightSelector = new MassSmallerThanOrEqSelector(500.0);
+    assertTrue(lightSelector.test(lightCreature));
+    assertFalse(lightSelector.test(heavyCreature));
+  }
+}