Limitations preventing mainstream use

I have recently reviewed the out-of-the-box openapi-generator without any custom java code and I have decided not to use it because of the following issues associated with generating clients (adapters) in typescript.

This generator has several significant limitations that make it unsuitable for our production use:

1. Non-idiomatic URL Generation: Mustache's logic-less design prevents generating modern template literals path parameters use verbose .replace() chaining instead of clean ${param} syntax Example: /v1/users/{uid}/state.replace('uid', String(uid)) instead of /v1/users/${uid}/state No fix available without complex post-processing
2. Duplicate Method Name Handling OpenAPI Generator inconsistently handles duplicate endpoint definitions numeric suffixes (_1, _2, etc.) are not reliably added to duplicate methods results in TypeScript compilation errors due to duplicate identifiers requires manual intervention or custom post-processing scripts
3. Our generated code should use an Enum: RestCallMethods.delete, but this is not possible with the current implementation. Reserved Keyword Issues DELETE HTTP method generates _delete due to JavaScript reserved keywords OpenAPI Generator converts delete to _delete before template processing. No clean template-level solution without workarounds. Enum access becomes inconsistent compared to other HTTP methods.
4. Limited Customization mustache templates cannot perform string transformations or conditional logic Complex formatting requirements need external post-processingTemplate maintenance becomes difficult as edge cases accumulate

No source file or test is named. Start by locating the TypeScript client generator and its Mustache template processing, then narrow the report to one reproducible limitation with an explicit expected output and regression test.