DefaultFieldNameInferrer (ToCamelCase) doesn't work like CamelCase of serializers

[cwuethrich]

Elastic.Clients.Elasticsearch version: 8.14.6

Elasticsearch version: 8.14.3

.NET runtime version: all

Operating system version: all

Description of the problem including expected versus actual behavior:
The ToCamelCase extension as backup of the DefaultFieldNameInferrer doesn't work like the CamelCase namigs of System.Text.Json or Newtonsoft.Json. For example a property named DBName ends as dBName instead of dbName.
This behavior ends in exceptions if you use strict mapping.

Steps to reproduce:

var settings = ***
var client = new ElasticsearchClient(settings);

string indexName = "test";
var createIndexResponse = await client.Indices.CreateAsync<MyDocument>(indexName, d => d
	.Mappings(m => m
		.Dynamic(DynamicMapping.Strict)
		.Properties(p => p
			.Keyword(d => d.DBName)
		)
	));
if (!createIndexResponse.IsSuccess())
{
	if (createIndexResponse.TryGetOriginalException(out Exception ex))
		throw ex;
}

var indexResponse = await client.IndexAsync(
	document: new MyDocument() { DBName = "database" },
	index: indexName,
	id: null);
if (!indexResponse.IsSuccess())
{
	if (indexResponse.TryGetOriginalException(out Exception ex))
		throw ex; // throws strict_dynamic_mapping_exception 
}

Expected behavior
The property name DBName should ends as dbName in property mapping.

[flobernd]

Hi @cwuethrich, thanks for reporting! I'll have a look.

The current implementation of ToCamelCase is a very simple stub, if I remember correctly.

[cwuethrich]

Hi @flobernd
This got merged impressively fast. Thanks a lot!

[flobernd]

No problem at all @cwuethrich ! Thanks again for the PR. A new release with the fix included will happen later this week 🙂