Add a map subject.

core/src/main/java/org/truth0/TestVerb.java

@@ -19,6 +19,7 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
+import java.util.Map;
 
 import org.truth0.subjects.BooleanSubject;
 import org.truth0.subjects.ClassSubject;
@@ -27,6 +28,7 @@
 import org.truth0.subjects.IntegerSubject;
 import org.truth0.subjects.IterableSubject;
 import org.truth0.subjects.ListSubject;
+import org.truth0.subjects.MapSubject;
 import org.truth0.subjects.StringSubject;
 import org.truth0.subjects.Subject;
 
@@ -77,4 +79,9 @@ public <T, C extends List<T>> ListSubject<? extends ListSubject<?, T, C>, T, C>
   public <T, C extends List<T>> ListSubject<? extends ListSubject<?, T, C>, T, C> that(T[] target) {
     return that(Arrays.asList(target));
   }
+
+  public <K, V, M extends Map<K, V>> MapSubject<? extends MapSubject<?, K, V, M>, K, V, M> that(Map<K, V> target) {
+    return MapSubject.create(getFailureStrategy(), target);
+  }
+
 }

core/src/main/java/org/truth0/subjects/MapSubject.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2011 David Saff
+ * Copyright (c) 2011 Christian Gruber
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.truth0.subjects;
+
+import java.util.Map;
+
+import org.truth0.FailureStrategy;
+
+import com.google.common.annotations.GwtCompatible;
+import com.google.common.collect.ImmutableList;
+
+/**
+ * @author Christian Gruber (cgruber@israfil.net)
+ */
+@GwtCompatible
+public class MapSubject<S extends MapSubject<S, K, V, M>, K, V, M extends Map<K, V>> extends Subject<S, M> {
+
+  public MapSubject(FailureStrategy failureStrategy, M map) {
+    super(failureStrategy, map);
+  }
+
+  /**
+   * Attests that the subject holds no objects, or fails.
+   */
+  public void isEmpty() {
+    if (!getSubject().isEmpty()) {
+      fail("is empty");
+    }
+  }
+
+  /**
+   * Attests that the subject holds one or more objects, or fails
+   */
+  public void isNotEmpty() {
+    if (getSubject().isEmpty()) {
+      fail("is not empty");
+    }
+  }
+
+  /**
+   * Attests that the subject contains the provided key or fails.
+   */
+  public WithValue<V> hasKey(final K key) {
+    if (!getSubject().containsKey(key)) {
+      fail("has key", key);
+    }
+    return new WithValue<V>() {
+      @Override public void withValue(V expected) {
+        V actual = getSubject().get(key);
+        if ((actual == null && key != null) ||
+            !actual.equals(expected)) {
+          fail("has key/value pair", ImmutableList.of(key, expected),
+              "actually has key/value pair", ImmutableList.of(key, actual));
+        }
+      }
+    };
+  }
+
+  public void lacksKey(K key) {
+    if (getSubject().containsKey(key)) {
+      fail("lacks key", key);
+    }
+  }
+
+  public void hasValue(V key) {
+    if (!getSubject().containsValue(key)) {
+      fail("has value", key);
+    }
+  }
+
+  public void lacksValue(V key) {
+    if (getSubject().containsValue(key)) {
+      fail("lacks value", key);
+    }
+  }
+
+  public interface WithValue<V> {
+    void withValue(V value);
+  }
+
+  @SuppressWarnings({ "unchecked", "rawtypes" })
+  public static <K, V, M extends Map<K, V>> MapSubject<? extends MapSubject<?, K, V, M>, K, V, M> create(
+      FailureStrategy failureStrategy, Map<K, V> map) {
+    return new MapSubject(failureStrategy, map);
+  }
+
+}

core/src/test/java/org/truth0/subjects/MapTest.java

@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2011 David Saff
+ * Copyright (c) 2011 Christian Gruber
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.truth0.subjects;
+
+import static org.junit.Assert.fail;
+import static org.truth0.Truth.ASSERT;
+
+import java.util.Map;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import com.google.common.collect.Maps;
+
+/**
+ * Tests for Map Subjects.
+ *
+ * @author Christian Gruber (cgruber@israfil.net)
+ */
+@RunWith(JUnit4.class)
+public class MapTest {
+
+  @Test public void mapIsEmpty() {
+    ASSERT.that(map(String.class, String.class)).isEmpty();
+  }
+
+  @Test public void mapIsEmptyWithFailure() {
+    try {
+      ASSERT.that(map(Integer.class, Integer.class, 1, 5)).isEmpty();
+      fail("Should have thrown.");
+    } catch (AssertionError e) {
+      ASSERT.that(e.getMessage()).contains("Not true that");
+      ASSERT.that(e.getMessage()).contains("is empty");
+    }
+  }
+
+  @Test public void mapIsNotEmpty() {
+    ASSERT.that(map(Integer.class, Integer.class, 1, 5)).isNotEmpty();
+  }
+
+  @Test public void mapIsNotEmptyWithFailure() {
+    try {
+      ASSERT.that(map(String.class, String.class)).isNotEmpty();
+      fail("Should have thrown.");
+    } catch (AssertionError e) {
+      ASSERT.that(e.getMessage()).contains("Not true that");
+      ASSERT.that(e.getMessage()).contains("is not empty");
+    }
+  }
+
+  @Test public void mapHasKey() {
+    ASSERT.that(map(String.class, Object.class, "a", "A")).hasKey("a");
+  }
+
+  @Test public void failMapHasKey() {
+    try {
+      ASSERT.that(map(String.class, Object.class, "a", "A")).hasKey("b");
+      fail("Should have thrown.");
+    } catch (AssertionError e) {
+      ASSERT.that(e.getMessage()).contains("Not true that");
+      ASSERT.that(e.getMessage()).contains("has key");
+    }
+  }
+
+  @Test public void failMapHasKeyWithNull() {
+    try {
+      ASSERT.that(map(String.class, Object.class, "a", "A")).hasKey(null);
+      fail("Should have thrown.");
+    } catch (AssertionError e) {
+      ASSERT.that(e.getMessage()).contains("Not true that");
+      ASSERT.that(e.getMessage()).contains("has key <null>");
+    }
+  }
+
+  @Test public void mapLacksKey() {
+    ASSERT.that(map(String.class, Object.class, "a", "A")).lacksKey("b");
+  }
+
+  @Test public void failMapLacksKey() {
+    try {
+      ASSERT.that(map(String.class, Object.class, "a", "A")).lacksKey("a");
+      fail("Should have thrown.");
+    } catch (AssertionError e) {
+      ASSERT.that(e.getMessage()).contains("Not true that");
+      ASSERT.that(e.getMessage()).contains("lacks key");
+    }
+  }
+
+  @Test public void mapHasKeyWithValue() {
+    ASSERT.that(map(String.class, Object.class, "a", String.class))
+      .hasKey("a").withValue(String.class);
+  }
+
+  @Test public void failMapHasKeyWithValue() {
+    try {
+      ASSERT.that(map(String.class, Object.class, "a", String.class))
+          .hasKey("a").withValue(Integer.class);
+      fail("Should have thrown.");
+    } catch (AssertionError e) {
+      ASSERT.that(e.getMessage()).contains("Not true that");
+      ASSERT.that(e.getMessage()).contains("has key/value pair");
+    }
+  }
+
+  @Test public void mapHasValue() {
+    ASSERT.that(map(String.class, Object.class, "a", "A")).hasValue("A");
+  }
+
+  @Test public void mapHasValueWithNull() {
+    ASSERT.that(map(String.class, Object.class, "a", null)).hasValue(null);
+  }
+
+  @Test public void failMapHasValue() {
+    try {
+      ASSERT.that(map(String.class, Object.class, "a", "A")).hasValue("B");
+      fail("Should have thrown.");
+    } catch (AssertionError e) {
+      ASSERT.that(e.getMessage()).contains("Not true that");
+      ASSERT.that(e.getMessage()).contains("has value");
+    }
+  }
+
+  @Test public void mapLacksValue() {
+    ASSERT.that(map(String.class, Object.class, "a", "A")).lacksValue("B");
+  }
+
+  @Test public void failMapLacksValue() {
+    try {
+      ASSERT.that(map(String.class, Object.class, "a", "A")).lacksValue("A");
+      fail("Should have thrown.");
+    } catch (AssertionError e) {
+      ASSERT.that(e.getMessage()).contains("Not true that");
+      ASSERT.that(e.getMessage()).contains("lacks value");
+    }
+  }
+
+
+  @SuppressWarnings("unchecked") // Want this to blow up if wrong.
+  public static <K, V> Map<K, V> map(Class<K> keyClass, Class<V> valueClass, Object ... keyval) {
+    Map<K, V> map = Maps.newHashMap();
+    if (keyval.length % 2 != 0)
+      throw new IllegalArgumentException("Wrong number of key/value pairs.");
+    for (int i = 0; i < keyval.length ; i = i + 2) {
+      map.put(keyClass.cast(keyval[i]), valueClass.cast(keyval[i + 1]));
+    }
+    return map;
+  }
+}