Merge branch '__rultor'

src/main/java/org/cactoos/map/MapEnvelope.java

@@ -25,9 +25,11 @@
 
 import java.util.Collection;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import org.cactoos.Scalar;
 import org.cactoos.scalar.And;
+import org.cactoos.scalar.EqualsNullable;
 import org.cactoos.scalar.Folded;
 import org.cactoos.scalar.Or;
 import org.cactoos.scalar.SumOfInt;
@@ -44,6 +46,7 @@
  * @see Sticky
  * @since 0.24
  * @checkstyle AbstractClassNameCheck (500 lines)
+ * @checkstyle ClassDataAbstractionCouplingCheck (500 lines)
  */
 @SuppressWarnings(
     {
@@ -163,16 +166,11 @@ public final int hashCode() {
         return new Unchecked<>(
             new Folded<>(
                 42,
-                (hash, entry) -> {
-                    final int keys = new SumOfInt(
-                        () -> 37 * hash,
-                        () -> entry.getKey().hashCode()
-                    ).value();
-                    return new SumOfInt(
-                        () -> 37 * keys,
-                        () -> entry.getValue().hashCode()
-                    ).value();
-                },
+                (hash, entry) -> new SumOfInt(
+                    () -> 37 * hash,
+                    () -> entry.getKey().hashCode(),
+                    () -> Objects.hashCode(entry.getValue())
+                ).value(),
                 this.map.value().entrySet()
             )
         ).value();
@@ -188,11 +186,12 @@ private Boolean contentsEqual(final Map<?, ?> other) {
         return new Unchecked<>(
             new And(
                 (entry) -> {
-                    final X key = entry.getKey();
-                    final Y value = entry.getValue();
                     return new And(
-                        () -> other.containsKey(key),
-                        () -> other.get(key).equals(value)
+                        () -> other.containsKey(entry.getKey()),
+                        () -> new EqualsNullable(
+                            () -> other.get(entry.getKey()),
+                            entry.getValue()
+                        ).value()
                     ).value();
                 }, this.entrySet()
             )

src/main/java/org/cactoos/scalar/EqualsNullable.java

@@ -0,0 +1,90 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2018 Yegor Bugayenko
+ *
+ * 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 NON-INFRINGEMENT. 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 org.cactoos.scalar;
+
+import org.cactoos.Scalar;
+
+/**
+ * Checks 2 objects for equality.
+ * Null values are accepted.
+ * <p>There is no thread-safety guarantee.
+ * @since 1.0
+ */
+public final class EqualsNullable implements Scalar<Boolean> {
+    /**
+     * The first object for comparison.
+     */
+    private final Scalar<Object> first;
+    /**
+     * The second object for comparison.
+     */
+    private final Scalar<Object> second;
+
+    /**
+     * Accepts 2 objects to compare.
+     * @param first Object to compare
+     * @param second Object to compare with
+     */
+    public EqualsNullable(final Object first, final Object second) {
+        this(() -> first, () -> second);
+    }
+
+    /**
+     * Accepts scalar to get value from and object to compare with.
+     * @param first Scalar to get value to compare
+     * @param second Object to compare with
+     */
+    public EqualsNullable(final Scalar<Object> first, final Object second) {
+        this(first, () -> second);
+    }
+
+    /**
+     * Accepts object to compare with and scalar to get value from.
+     * @param first Object to compare
+     * @param second Scalar to get value to compare
+     */
+    public EqualsNullable(final Object first, final Scalar<Object> second) {
+        this(() -> first, second);
+    }
+
+    /**
+     * Accepts 2 scalars to get get values from.
+     * @param first Scalar to get value to compare
+     * @param second Scalar to get value to compare with
+     */
+    public EqualsNullable(final Scalar<Object> first,
+        final Scalar<Object> second) {
+        this.first = first;
+        this.second = second;
+    }
+
+    @Override
+    @SuppressWarnings("PMD.CompareObjectsWithEquals")
+    public Boolean value() throws Exception {
+        final Object source = this.first.value();
+        final Object compared = this.second.value();
+        return source == compared
+            || source != null && source.equals(compared);
+    }
+}

src/test/java/org/cactoos/map/MapEnvelopeTest.java

@@ -249,14 +249,14 @@ public void mapEqualsToMapWithSameEntries() {
         );
     }
 
-    @Test(expected = NullPointerException.class)
-    public void equalFailsOnNull() {
+    @Test
+    public void equalsDoesNotFailOnNulls() {
         final MapEntry<String, String> first =
             new MapEntry<>("key3", "value3");
         final MapEntry<String, String> second =
             new MapEntry<>("key4", null);
         MatcherAssert.assertThat(
-            "Map allows null values, but shouldn't",
+            "Map must allow null values",
             new MapOf<String, String>(first, second),
             new IsEqual<>(new MapOf<String, String>(first, second))
         );
@@ -307,8 +307,8 @@ public void hashCodeDependsOnItems() {
         );
     }
 
-    @Test(expected = NullPointerException.class)
-    public void hashCodeFailsOnNull() {
+    @Test
+    public void hashCodeDoesNotFailOnNulls() {
         final MapEntry<String, String> first =
             new MapEntry<>("key10", "value10");
         final MapEntry<String, String> second =

src/test/java/org/cactoos/scalar/EqualsNullableTest.java

@@ -0,0 +1,83 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2018 Yegor Bugayenko
+ *
+ * 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 NON-INFRINGEMENT. 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 org.cactoos.scalar;
+
+import org.junit.Test;
+import org.llorllale.cactoos.matchers.Assertion;
+import org.llorllale.cactoos.matchers.IsTrue;
+
+/**
+ * Test case for {@link EqualsNullable}.
+ *
+ * @since 1.0
+ * @checkstyle JavadocMethodCheck (500 lines)
+ */
+@SuppressWarnings("PMD.SuspiciousEqualsMethodName")
+public final class EqualsNullableTest {
+
+    @Test
+    public void nullEqualsNull() throws Exception {
+        new Assertion<>(
+            "Must return true for both null objects",
+            new EqualsNullable(() -> null, () -> null),
+            new IsTrue()
+        ).affirm();
+    }
+
+    @Test
+    public void equals() throws Exception {
+        new Assertion<>(
+            "Must return true for equal objects",
+            new EqualsNullable(1, 1),
+            new IsTrue()
+        ).affirm();
+    }
+
+    @Test
+    public void notEquals() throws Exception {
+        new Assertion<>(
+            "Must return false for non equal objects",
+            () -> !new EqualsNullable(1, 2).value(),
+            new IsTrue()
+        ).affirm();
+    }
+
+    @Test
+    public void equalsObjectAndScalar() throws Exception {
+        new Assertion<>(
+            "Must return true for object and scalar with the same value",
+            new EqualsNullable(1, () -> 1),
+            new IsTrue()
+        ).affirm();
+    }
+
+    @Test
+    public void equalsScalarAndObject() throws Exception {
+        new Assertion<>(
+            "Must return true for scalar and object with the same value",
+            new EqualsNullable(() -> 1, 1),
+            new IsTrue()
+        ).affirm();
+    }
+}