[BUG] Indices with a PathHierarchyTokenizer without optional config params cannot be deserialized

[moesterheld]

What is the bug?

An index with a path hierarchy tokenizer that is configured with missing optional parameters (see https://docs.opensearch.org/latest/analyzers/tokenizers/path-hierarchy/) cannot be deserialized with an error.
E.g. Missing required property 'PathHierarchyTokenizer.bufferSize'

How can one reproduce the bug?

• Create a index with path hierarchy tokenizer without setting optional parameters
• Try to retrieve this index using the IndicesClient

What is the expected behavior?

Index should be retrieved without throwing an exception

What is your host/environment?

OS 2.19.3
Client 3.2.0 / 3.3.0

Do you have any screenshots?

java.lang.RuntimeException: Missing required property 'PathHierarchyTokenizer.bufferSize'
	at org.opensearch.client.transport.httpclient5.ApacheHttpClient5Transport.extractAndWrapCause(ApacheHttpClient5Transport.java:1168)
	at org.opensearch.client.transport.httpclient5.ApacheHttpClient5Transport.performRequest(ApacheHttpClient5Transport.java:159)
	at org.opensearch.client.opensearch.indices.OpenSearchIndicesClientBase.get(OpenSearchIndicesClientBase.java:468)

Do you have any additional context?

Caused by requireNonNull checks in PathHierarchyTokenizer for optional parameters

    private PathHierarchyTokenizer(Builder builder) {
        super(builder);
        this.bufferSize = ApiTypeHelper.requireNonNull(builder.bufferSize, this, "bufferSize");
        this.delimiter = ApiTypeHelper.requireNonNull(builder.delimiter, this, "delimiter");
        this.replacement = builder.replacement;
        this.reverse = ApiTypeHelper.requireNonNull(builder.reverse, this, "reverse");
        this.skip = ApiTypeHelper.requireNonNull(builder.skip, this, "skip");
    }

[andrross]

Catch All Triage - 1 2 3

@moesterheld we would happily accept a PR if you're interested in submitting a fix!

[moesterheld]

@andrross I created a PR to fix this upstream in the spec

[gingeekrishna]

Opened PR #2038 to fix this. Same root cause as other similar issues: buffer_size, delimiter, reverse, and skip were all marked required in the spec, but they are optional parameters with documented OpenSearch defaults. Removed them from required in the spec and updated the generated class to use @Nullable types throughout.