Worked on the kintone/js-sdk repository to enhance type name validation logic for dts-gen, focusing on strict compliance with ECMA262 IdentifierName specifications. Addressed a bug where invalid JavaScript identifiers could be generated, which posed potential runtime risks. The solution involved refining character validation in TypeScript and JavaScript, ensuring only valid identifiers are produced. Comprehensive tests were added to cover edge cases, including Japanese characters, symbols, and leading spaces, verifying the robustness of the new logic. This update improved the reliability of typings generation, reduced the likelihood of runtime errors, and maintained build stability while expanding test coverage for the project.