Added test code for counting words in a string in Java

java-strings-3/src/test/java/com/baeldung/string/wordcount/WordCountUnitTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.string.wordcount;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+public class WordCountUnitTest {
+    private String string1 = "This is a test sentence with eight words";
+    private String string2 = "This#is%a test sentence with eight       words";
+
+    @Test
+    public void givenStringWith8Words_whenUsingRegexCount_ThenResultEqual8() {
+        assertThat(WordCounter.countWordsUsingRegex(string2) == 8).isTrue();
+    }
+
+    @Test
+    public void givenStringWith8Words_whenUsingManualMethod_ThenWordCountEqual8() {
+        assertThat(WordCounter.countWordsManually(string1) == 8).isTrue();
+    }
+
+    @Test
+    public void givenAStringWith8Words_whenUsingTokenizer_ThenWordCountEqual8() {
+        assertThat(WordCounter.countWordsUsingTokenizer(string1) == 8).isTrue();
+    }
+}