Add tests for UnicodeLetterChecker

core-java-modules/core-java-string-operations-7/src/test/java/com/baeldung/unicode/UnicodeLetterCheckerUnitTest.java

@@ -0,0 +1,38 @@
+package com.baeldung.unicode;
+
+import org.junit.Test;
+import static org.junit.Assert.assertTrue;
+
+public class UnicodeLetterCheckerUnitTest {
+    @Test
+    public void givenString_whenUsingIsLetter_thenReturnTrue() {
+        UnicodeLetterChecker checker = new UnicodeLetterChecker();
+
+        boolean isUnicodeLetter = checker.characterClassCheck("HelloWorld");
+        assertTrue(isUnicodeLetter);
+    }
+
+    @Test
+    public void givenString_whenUsingRegex_thenReturnTrue() {
+        UnicodeLetterChecker checker = new UnicodeLetterChecker();
+
+        boolean isUnicodeLetter = checker.regexCheck("HelloWorld");
+        assertTrue(isUnicodeLetter);
+    }
+
+    @Test
+    public void givenString_whenUsingIsAlpha_thenReturnTrue() {
+        UnicodeLetterChecker checker = new UnicodeLetterChecker();
+
+        boolean isUnicodeLetter = checker.isAlphaCheck("HelloWorld");
+        assertTrue(isUnicodeLetter);
+    }
+
+    @Test
+    public void givenString_whenUsingStreams_thenReturnTrue() {
+        UnicodeLetterChecker checker = new UnicodeLetterChecker();
+
+        boolean isUnicodeLetter = checker.StreamsCheck("HelloWorld");
+        assertTrue(isUnicodeLetter);
+    }
+}