BAEL-1580: Hamcrest number matchers. (#3749)

* BAEL-1580: Hamcrest number matchers.

* BAEL-1580: Moving hamcrest test to module mockito.

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

@@ -0,0 +1,152 @@
+package org.baeldung.hamcrest;
+
+import org.junit.Test;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.*;
+import static org.hamcrest.Matchers.closeTo;
+
+public class HamcrestNumberUnitTest {
+
+    @Test
+    public void givenADouble_whenCloseTo_thenCorrect() {
+        double actual = 1.3;
+        double operand = 1;
+        double error = 0.5;
+        assertThat(actual, is(closeTo(operand, error)));
+    }
+
+    @Test
+    public void givenADouble_whenNotCloseTo_thenCorrect() {
+        double actual = 1.6;
+        double operand = 1;
+        double error = 0.5;
+        assertThat(actual, is(not(closeTo(operand, error))));
+    }
+
+    @Test
+    public void givenABigDecimal_whenCloseTo_thenCorrect() {
+        BigDecimal actual = new BigDecimal("1.0003");
+        BigDecimal operand = new BigDecimal("1");
+        BigDecimal error = new BigDecimal("0.0005");
+        assertThat(actual, is(closeTo(operand, error)));
+    }
+
+    @Test
+    public void givenABigDecimal_whenNotCloseTo_thenCorrect() {
+        BigDecimal actual = new BigDecimal("1.0006");
+        BigDecimal operand = new BigDecimal("1");
+        BigDecimal error = new BigDecimal("0.0005");
+        assertThat(actual, is(not(closeTo(operand, error))));
+    }
+
+    @Test
+    public void given7_whenGreaterThan5_thenCorrect() {
+        Integer seven = 7;
+        Integer five = 5;
+        assertThat(seven, is(greaterThan(five)));
+    }
+
+    @Test
+    public void given7_whenGreaterThanOrEqualTo5_thenCorrect() {
+        Integer seven = 7;
+        Integer five = 5;
+        assertThat(seven, is(greaterThanOrEqualTo(five)));
+    }
+
+    @Test
+    public void given5_whenGreaterThanOrEqualTo5_thenCorrect() {
+        Integer five = 5;
+        assertThat(five, is(greaterThanOrEqualTo(five)));
+    }
+
+    @Test
+    public void given3_whenLessThan5_thenCorrect() {
+        Integer three = 3;
+        Integer five = 5;
+        assertThat(three, is(lessThan(five)));
+    }
+
+    @Test
+    public void given3_whenLessThanOrEqualTo5_thenCorrect() {
+        Integer three = 3;
+        Integer five = 5;
+        assertThat(three, is(lessThanOrEqualTo(five)));
+    }
+
+    @Test
+    public void given5_whenLessThanOrEqualTo5_thenCorrect() {
+        Integer five = 5;
+        assertThat(five, is(lessThanOrEqualTo(five)));
+    }
+
+    @Test
+    public void givenBenjamin_whenGreaterThanAmanda_thenCorrect() {
+        String amanda = "Amanda";
+        String benjamin = "Benjamin";
+        assertThat(benjamin, is(greaterThan(amanda)));
+    }
+
+    @Test
+    public void givenAmanda_whenLessThanBenajmin_thenCorrect() {
+        String amanda = "Amanda";
+        String benjamin = "Benjamin";
+        assertThat(amanda, is(lessThan(benjamin)));
+    }
+
+    @Test
+    public void givenToday_whenGreaterThanYesterday_thenCorrect() {
+        LocalDate today = LocalDate.now();
+        LocalDate yesterday = today.minusDays(1);
+        assertThat(today, is(greaterThan(yesterday)));
+    }
+
+    @Test
+    public void givenToday_whenLessThanTomorrow_thenCorrect() {
+        LocalDate today = LocalDate.now();
+        LocalDate tomorrow = today.plusDays(1);
+        assertThat(today, is(lessThan(tomorrow)));
+    }
+
+    @Test
+    public void givenAmanda_whenOlderThanBenjamin_thenCorrect() {
+        Person amanda = new Person("Amanda", 20);
+        Person benjamin = new Person("Benjamin", 18);
+        assertThat(amanda, is(greaterThan(benjamin)));
+    }
+
+    @Test
+    public void givenBenjamin_whenYoungerThanAmanda_thenCorrect() {
+        Person amanda = new Person("Amanda", 20);
+        Person benjamin = new Person("Benjamin", 18);
+        assertThat(benjamin, is(lessThan(amanda)));
+    }
+
+    class Person implements Comparable<Person> {
+        String name;
+        int age;
+
+        public Person(String name, int age) {
+            this.name = name;
+            this.age = age;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public int getAge() {
+            return age;
+        }
+
+        @Override
+        public int compareTo(Person o) {
+            if (this.age == o.getAge()) return 0;
+            if (this.age > o.age) return 1;
+            else return -1;
+        }
+    }
+}