Fixed test cases according to the article

core-java/src/test/java/com/baeldung/regexp/datepattern/FormattedDateMatcherUnitTest.java

@@ -1,16 +1,24 @@
 package com.baeldung.regexp.datepattern;
 
-import com.baeldung.regexp.datepattern.gregorian.testhelper.GregorianDateTestHelper;
+import org.junit.Assert;
 import org.junit.Test;
 
 public class FormattedDateMatcherUnitTest {
 
     private DateMatcher matcher = new FormattedDateMatcher();
 
-    private GregorianDateTestHelper testHelper = new GregorianDateTestHelper(matcher);
-
     @Test
     public void whenUsingFormattedDateMatcher_thenFormatConstraintsSatisfied() {
-        testHelper.assertFormat();
+        Assert.assertTrue(matcher.matches("2017-12-31"));
+        Assert.assertTrue(matcher.matches("2018-01-01"));
+        Assert.assertTrue(matcher.matches("0000-00-00"));
+        Assert.assertTrue(matcher.matches("1029-99-72"));
+
+        Assert.assertFalse(matcher.matches("2018-01"));
+        Assert.assertFalse(matcher.matches("2018-01-01-01"));
+        Assert.assertFalse(matcher.matches("2018-01-XX"));
+        Assert.assertFalse(matcher.matches(" 2018-01-01"));
+        Assert.assertFalse(matcher.matches("2018-01-01 "));
+        Assert.assertFalse(matcher.matches("2018/01/01"));
     }
 }

core-java/src/test/java/com/baeldung/regexp/datepattern/RangedDateMatcherUnitTest.java

@@ -1,21 +1,31 @@
 package com.baeldung.regexp.datepattern;
 
-import com.baeldung.regexp.datepattern.gregorian.testhelper.GregorianDateTestHelper;
+import org.junit.Assert;
 import org.junit.Test;
 
 public class RangedDateMatcherUnitTest {
 
     private DateMatcher matcher = new RangedDateMatcher();
 
-    private GregorianDateTestHelper testHelper = new GregorianDateTestHelper(matcher);
-
     @Test
     public void whenUsingRangedDateMatcher_thenFormatConstraintsSatisfied() {
-        testHelper.assertFormat();
+        Assert.assertFalse(matcher.matches("2018-01"));
+        Assert.assertFalse(matcher.matches("2018-01-01-01"));
+        Assert.assertFalse(matcher.matches("2018-01-XX"));
+        Assert.assertFalse(matcher.matches(" 2018-01-01"));
+        Assert.assertFalse(matcher.matches("2018-01-01 "));
+        Assert.assertFalse(matcher.matches("2018/01/01"));
     }
 
     @Test
     public void whenUsingRangedDateMatcher_thenRangeConstraintsSatisfied() {
-        testHelper.assertRange();
+        Assert.assertTrue(matcher.matches("1900-01-01"));
+        Assert.assertTrue(matcher.matches("2018-02-31"));
+        Assert.assertTrue(matcher.matches("2999-12-31"));
+
+        Assert.assertFalse(matcher.matches("1899-12-31"));
+        Assert.assertFalse(matcher.matches("2018-05-35"));
+        Assert.assertFalse(matcher.matches("2018-13-05"));
+        Assert.assertFalse(matcher.matches("3000-01-01"));
     }
 }

core-java/src/test/java/com/baeldung/regexp/datepattern/gregorian/testhelper/GregorianDateTestHelper.java

@@ -15,12 +15,13 @@ public class GregorianDateTestHelper {
         Assert.assertTrue(matcher.matches("2017-12-31"));
         Assert.assertTrue(matcher.matches("2018-01-01"));
 
-        Assert.assertFalse(matcher.matches("2018-01"));
-        Assert.assertFalse(matcher.matches("2018-01-01-01"));
-        Assert.assertFalse(matcher.matches("2018-01-XX"));
-        Assert.assertFalse(matcher.matches(" 2018-01-01"));
-        Assert.assertFalse(matcher.matches("2018-01-01 "));
-        Assert.assertFalse(matcher.matches("2018/01/01 "));
+        Assert.assertFalse(matcher.matches("2018-02"));
+        Assert.assertFalse(matcher.matches("2018-02-01-01"));
+        Assert.assertFalse(matcher.matches("2018-02-XX"));
+        Assert.assertFalse(matcher.matches(" 2018-02-01"));
+        Assert.assertFalse(matcher.matches("2018-02-01 "));
+        Assert.assertFalse(matcher.matches("2020/02/28"));
+        Assert.assertFalse(matcher.matches("2020.02.29"));
     }
 
     public void assertRange() {
@@ -29,18 +30,19 @@ public class GregorianDateTestHelper {
         Assert.assertTrue(matcher.matches("2999-12-31"));
 
         Assert.assertFalse(matcher.matches("1899-12-31"));
+        Assert.assertFalse(matcher.matches("2018-05-35"));
+        Assert.assertFalse(matcher.matches("2018-13-05"));
         Assert.assertFalse(matcher.matches("3000-01-01"));
+        Assert.assertFalse(matcher.matches("3200-02-29"));
     }
 
     public void assertFebruary29th() {
         Assert.assertTrue(matcher.matches("2000-02-29"));
         Assert.assertTrue(matcher.matches("2400-02-29"));
         Assert.assertTrue(matcher.matches("2800-02-29"));
-        Assert.assertTrue(matcher.matches("2004-02-29"));
-        Assert.assertTrue(matcher.matches("2008-02-29"));
-        Assert.assertTrue(matcher.matches("2012-02-29"));
-        Assert.assertTrue(matcher.matches("2016-02-29"));
         Assert.assertTrue(matcher.matches("2020-02-29"));
+        Assert.assertTrue(matcher.matches("2024-02-29"));
+        Assert.assertTrue(matcher.matches("2028-02-29"));
 
         Assert.assertFalse(matcher.matches("2017-02-29"));
         Assert.assertFalse(matcher.matches("2018-02-29"));
@@ -52,8 +54,8 @@ public class GregorianDateTestHelper {
 
     public void assertFebruaryGeneralDates() {
         Assert.assertTrue(matcher.matches("2018-02-01"));
-        Assert.assertTrue(matcher.matches("2018-02-13"));
-        Assert.assertTrue(matcher.matches("2018-02-25"));
+        Assert.assertTrue(matcher.matches("2019-02-13"));
+        Assert.assertTrue(matcher.matches("2020-02-25"));
 
         Assert.assertFalse(matcher.matches("2000-02-30"));
         Assert.assertFalse(matcher.matches("2400-02-62"));
@@ -62,39 +64,39 @@ public class GregorianDateTestHelper {
 
     public void assertMonthsOf30Days() {
         Assert.assertTrue(matcher.matches("2018-04-30"));
-        Assert.assertTrue(matcher.matches("2018-06-30"));
-        Assert.assertTrue(matcher.matches("2018-09-30"));
-        Assert.assertTrue(matcher.matches("2018-11-30"));
+        Assert.assertTrue(matcher.matches("2019-06-30"));
+        Assert.assertTrue(matcher.matches("2020-09-30"));
+        Assert.assertTrue(matcher.matches("2021-11-30"));
 
-        Assert.assertTrue(matcher.matches("2018-04-02"));
-        Assert.assertTrue(matcher.matches("2018-04-14"));
-        Assert.assertTrue(matcher.matches("2018-04-26"));
+        Assert.assertTrue(matcher.matches("2022-04-02"));
+        Assert.assertTrue(matcher.matches("2023-06-14"));
+        Assert.assertTrue(matcher.matches("2024-09-26"));
 
         Assert.assertFalse(matcher.matches("2018-04-31"));
-        Assert.assertFalse(matcher.matches("2018-06-31"));
-        Assert.assertFalse(matcher.matches("2018-09-31"));
-        Assert.assertFalse(matcher.matches("2018-11-31"));
+        Assert.assertFalse(matcher.matches("2019-06-31"));
+        Assert.assertFalse(matcher.matches("2020-09-31"));
+        Assert.assertFalse(matcher.matches("2021-11-31"));
 
-        Assert.assertFalse(matcher.matches("2018-04-32"));
-        Assert.assertFalse(matcher.matches("2018-04-64"));
-        Assert.assertFalse(matcher.matches("2018-04-96"));
+        Assert.assertFalse(matcher.matches("2022-04-32"));
+        Assert.assertFalse(matcher.matches("2023-06-64"));
+        Assert.assertFalse(matcher.matches("2024-09-96"));
     }
 
     public void assertMonthsOf31Dates() {
         Assert.assertTrue(matcher.matches("2018-01-31"));
-        Assert.assertTrue(matcher.matches("2018-03-31"));
-        Assert.assertTrue(matcher.matches("2018-05-31"));
-        Assert.assertTrue(matcher.matches("2018-07-31"));
-        Assert.assertTrue(matcher.matches("2018-08-31"));
-        Assert.assertTrue(matcher.matches("2018-10-31"));
-        Assert.assertTrue(matcher.matches("2018-12-31"));
+        Assert.assertTrue(matcher.matches("2019-03-31"));
+        Assert.assertTrue(matcher.matches("2020-05-31"));
+        Assert.assertTrue(matcher.matches("2021-07-31"));
+        Assert.assertTrue(matcher.matches("2022-08-31"));
+        Assert.assertTrue(matcher.matches("2023-10-31"));
+        Assert.assertTrue(matcher.matches("2024-12-31"));
 
-        Assert.assertTrue(matcher.matches("2018-01-03"));
-        Assert.assertTrue(matcher.matches("2018-01-15"));
-        Assert.assertTrue(matcher.matches("2018-01-27"));
+        Assert.assertTrue(matcher.matches("2025-01-03"));
+        Assert.assertTrue(matcher.matches("2026-03-15"));
+        Assert.assertTrue(matcher.matches("2027-05-27"));
 
         Assert.assertFalse(matcher.matches("2018-01-32"));
-        Assert.assertFalse(matcher.matches("2018-01-64"));
-        Assert.assertFalse(matcher.matches("2018-01-96"));
+        Assert.assertFalse(matcher.matches("2019-03-64"));
+        Assert.assertFalse(matcher.matches("2020-05-96"));
     }
 }