BAEL-1579: Hamcrest custom matchers.

testing-modules/mockito/pom.xml

@@ -51,7 +51,6 @@
             <groupId>org.hamcrest</groupId>
             <artifactId>java-hamcrest</artifactId>
             <version>${hamcrest.version}</version>
-            <scope>test</scope>
         </dependency>
 
     </dependencies>

testing-modules/mockito/src/main/java/org/baeldung/hamcrest/custommatchers/IsDivisibleBy.java

@@ -0,0 +1,28 @@
+package org.baeldung.hamcrest.custommatchers;
+
+import org.hamcrest.Description;
+import org.hamcrest.Matcher;
+import org.hamcrest.TypeSafeMatcher;
+
+public class IsDivisibleBy extends TypeSafeMatcher<Integer> {
+
+    private Integer divider;
+
+    private IsDivisibleBy(Integer divider) {
+        this.divider = divider;
+    }
+
+    @Override
+    protected boolean matchesSafely(Integer dividend) {
+        return ((dividend % divider) == 0);
+    }
+
+    @Override
+    public void describeTo(Description description) {
+        description.appendText("divisible by " + divider);
+    }
+
+    public static Matcher<Integer> divisibleBy(Integer divider) {
+        return new IsDivisibleBy(divider);
+    }
+}

testing-modules/mockito/src/main/java/org/baeldung/hamcrest/custommatchers/IsOnlyNumbers.java

@@ -0,0 +1,27 @@
+package org.baeldung.hamcrest.custommatchers;
+
+import org.hamcrest.Description;
+import org.hamcrest.Matcher;
+import org.hamcrest.TypeSafeMatcher;
+
+public class IsOnlyNumbers extends TypeSafeMatcher<String> {
+
+    @Override
+    protected boolean matchesSafely(String s) {
+        try {
+            Integer.parseInt(s);
+            return true;
+        } catch (NumberFormatException nfe) {
+            return false;
+        }
+    }
+
+    @Override
+    public void describeTo(Description description) {
+        description.appendText("only numbers");
+    }
+
+    public static Matcher<String> onlyNumbers() {
+        return new IsOnlyNumbers();
+    }
+}

testing-modules/mockito/src/main/java/org/baeldung/hamcrest/custommatchers/IsUppercase.java

@@ -0,0 +1,22 @@
+package org.baeldung.hamcrest.custommatchers;
+
+import org.hamcrest.Description;
+import org.hamcrest.Matcher;
+import org.hamcrest.TypeSafeMatcher;
+
+public class IsUppercase extends TypeSafeMatcher<String> {
+
+    @Override
+    protected boolean matchesSafely(String s) {
+        return s.equals(s.toUpperCase());
+    }
+
+    @Override
+    public void describeTo(Description description) {
+        description.appendText("all uppercase");
+    }
+
+    public static Matcher<String> uppercase() {
+        return new IsUppercase();
+    }
+}

testing-modules/mockito/src/test/java/org/baeldung/hamcrest/HamcrestCustomUnitTest.java

@@ -0,0 +1,50 @@
+package org.baeldung.hamcrest;
+
+import org.junit.Test;
+
+import static org.baeldung.hamcrest.custommatchers.IsDivisibleBy.divisibleBy;
+import static org.baeldung.hamcrest.custommatchers.IsOnlyNumbers.onlyNumbers;
+import static org.baeldung.hamcrest.custommatchers.IsUppercase.uppercase;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+
+public class HamcrestCustomUnitTest {
+
+    @Test
+    public final void givenAString_whenIsOnlyNumbers_thenCorrect() {
+        String numbers = "123";
+
+        assertThat(numbers, is(onlyNumbers()));
+    }
+
+    @Test
+    public final void givenAString_whenIsNotOnlyNumbers_thenCorrect() {
+        String numbers = "123ABC";
+
+        assertThat(numbers, is(not(onlyNumbers())));
+    }
+
+    @Test
+    public final void givenAString_whenIsUppercase_thenCorrect() {
+        String uppercaseWord = "HELLO";
+
+        assertThat(uppercaseWord, is(uppercase()));
+    }
+
+    @Test
+    public final void givenAnEvenInteger_whenDivisibleByTwo_thenCorrect() {
+        Integer ten = 10;
+        Integer two = 2;
+
+        assertThat(ten, is(divisibleBy(two)));
+    }
+
+    @Test
+    public final void givenAnOddInteger_whenNotDivisibleByTwo_thenCorrect() {
+        Integer eleven = 11;
+        Integer two = 2;
+
+        assertThat(eleven, is(not(divisibleBy(two))));
+    }
+}