The transformation looks mechanical: split into words, lowercase the first, capitalise the rest, join. Acronyms are where every implementation has to make a choice.
HTTP or Http
Is it parseHTTPResponse or parseHttpResponse? Both conventions exist in wide use. The second is easier to reverse mechanically, because HTTPResponse gives a splitter no way to tell where the acronym ends — HTTPResponse could split as HTTP + Response or H + TTP + Response without a dictionary.
Round-tripping is not guaranteed
Converting snakecase to camelCase and back should return the original. It does not when the input contains consecutive underscores, leading underscores, or digits adjacent to letters — v2api and v2api can both produce v2Api.
Identifiers cannot start with a digit
A label beginning with a number produces an invalid identifier in most languages. Prefix it or the generated code will not parse, and the failure happens at build time rather than in the conversion.
Try it: Convert to camelCase on SeoWolf's Notepad.