Added simple logic to make most identifier strings valid

[Fargekritt]

---

name: Pull request
title: 'Added simple logic to make most identifier strings valid'
labels: bug fix
assignees: Fargekritt

---

Description:

Adds an _ to operationIds that don´t have a valid first char to make safe identifier names
This approach is not perfect and have some flaws but will cover most normal cases. operationId: "return" should @ instead of _but both works
official Identifier-name naming rules

Code Generator creates unsafe interface method names #360

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.90%. Comparing base (ce01537) to head (9772296).
Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #562      +/-   ##
==========================================
- Coverage   97.31%   94.90%   -2.41%     
==========================================
  Files          52       53       +1     
  Lines        2572     2612      +40     
==========================================
- Hits         2503     2479      -24     
- Misses         46       98      +52     
- Partials       23       35      +12     

Flag	Coverage Δ
unittests	94.90% <100.00%> (-2.41%)	⬇️

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[christianhelle]

@Fargekritt Good stuff! Thanks for taking the time to work on this

I pulled this branch and tried it out locally and also tried the test case you provided to run on the main branch and it failed as it should

[christianhelle]

This resolves #360