Changed the test for RegexValidator class

src/main/java/org/opensearch/sdk/sample/helloworld/ExampleCustomSettingConfig.java

@@ -17,16 +17,14 @@
  * {@link ExampleCustomSettingConfig} contains the custom settings value and their static declarations.
  */
 public class ExampleCustomSettingConfig {
-    private static final String FORBIDDEN_REGEX = "forbidden";
-
+    private static final String FORBIDDEN_VALUE = "forbidden";
     /**
-     * A string setting. If the string setting matches the FORBIDDEN_REGEX string, the validation will fail.
+     * A string setting. If the string setting matches the FORBIDDEN_REGEX string and parameter isMatching is true the validation will fail.
      */
     public static final Setting<String> VALIDATED_SETTING = Setting.simpleString(
         "custom.validate",
-        new RegexValidator(FORBIDDEN_REGEX),
+        new RegexValidator(FORBIDDEN_VALUE, false),
         Property.NodeScope,
         Property.Dynamic
     );
-
 }

src/test/java/org/opensearch/sdk/sample/helloworld/TestHelloWorldExtension.java

@@ -245,15 +245,17 @@ public void onFailure(Exception e) {
         assertEquals("failed to find action [" + UnregisteredAction.INSTANCE + "] to execute", ex.getMessage());
     }
 
+    @Test
     public void testValidatedSettings() {
-        final String expected = randomAlphaOfLengthBetween(1, 5);
+        final String expected = "foo";
         final String actual = VALIDATED_SETTING.get(Settings.builder().put(VALIDATED_SETTING.getKey(), expected).build());
         assertEquals(expected, actual);
 
-        final IllegalArgumentException exception = expectThrows(
+        final IllegalArgumentException exceptionTrue = expectThrows(
             IllegalArgumentException.class,
-            () -> VALIDATED_SETTING.get(Settings.builder().put("custom.validated", "it's forbidden").build())
+            () -> VALIDATED_SETTING.get(Settings.builder().put(VALIDATED_SETTING.getKey(), "it's forbidden").build())
         );
-        assertEquals("Setting must not contain [forbidden]", exception.getMessage());
+
+        assertEquals("Setting [it's forbidden] must match regex [forbidden]", exceptionTrue.getMessage());
     }
 }