[BUG] Hello World sample validator reverses logic

[dbwiddis]

What is the bug?

A sample validated setting was added to the HelloWorld extension in #421. It is based on original assumptions that a matching validator would fail. During review of the companion PR, the implementation reversed the logic so it now does the opposite of what's intended.

The unit test was missing the @Test annotation so it wasn't being adequately tested, as I noticed when reviewing code coverage.

How can one reproduce the bug?

1. Add the @Test annotation to TestHelloWorldExtension method testValidatedSettings().
2. Run gradle check

What is the expected behavior?

Tests pass.

Do you have any additional context?

Possible resolutions:

1. (Easy) Change the regular expression from "forbidden" to one that verifies a word doesn't exist. This is a confusing regex: "^((?!forbidden).)*$"
2. (Preferred) Update the validator to take a boolean parameter switching between "fail if it matches" or "fail if it doesn't match". This provides the most flexibility.

Bonus points:

• Add more validated settings like IP address matching

[Kuanysh-kst]

Hello @dbwiddis, I would like to take this issue

[dbwiddis]

Great! It's yours! This is one where you will need to create two PRs, one here and one on OpenSearch. On your local checkout you will make the change on OpenSearch branch and use ./gradlew publishToMavenLocal to have a copy that will let your SDK branch compile/test.

[Kuanysh-kst]

In the test testValidatedSettings() method, I get an error of 246 lines when I run Junit Test, I think I can temporarily remove the first 3 lines of this method to make this issue(I get an error because of this line: final String expected = randomAlphaOfLengthBetween(1, 5);)

[dbwiddis]

I think I can temporarily remove the first 3 lines of this method to make this issue(I get an error because of this line: final String expected = randomAlphaOfLengthBetween(1, 5);)

Yes, just remove that. It works on OpenSearch but we don't have the right setup for it to work for us. Just pick a test string of your own.

[Kuanysh-kst]

opensearch-project/OpenSearch#6823

[dbwiddis]

Done in #608 and opensearch-project/OpenSearch#6823