BAEL-5354 Add improvement to cover JDK11 solution to the repeated string problem (#11756)

core-java-modules/core-java-string-algorithms-3/pom.xml

@@ -49,8 +49,9 @@
     </build>
 
     <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
         <validator.version>1.7</validator.version>
         <apache-commons-lang3.version>3.12.0</apache-commons-lang3.version>
     </properties>
-
 </project>

core-java-modules/core-java-string-algorithms-3/src/test/java/com/baeldung/repeatedcharstring/RepeatedCharacterStringUnitTest.java

@@ -19,6 +19,18 @@ class RepeatedCharacterStringUnitTest {
     private static final String EXPECTED_STRING = "aaaaaaa";
     private static final int N = 7;
 
+    @Test
+    void givenSingleCharacterString_whenRepeat_thenStringCreated() {
+        String newString = "a".repeat(N);
+        assertEquals(EXPECTED_STRING, newString);
+    }
+
+    @Test
+    void givenMultiCharacterString_whenRepeat_thenStringCreated() {
+        String newString = "-->".repeat(5);
+        assertEquals("-->-->-->-->-->", newString);
+    }
+
     @Test
     void givenString_whenStringBuilderUsed_thenStringCreated() {
         StringBuilder builder = new StringBuilder(N);