fix(templates): handle null parameters and nullable fields in test generation

[Fluf22]

Jira: API-454

Summary

Extracted from #5860 — generic template fixes for null parameter handling across Go, Kotlin, Scala, and Swift.

Changes

• Go: Use nameInPascalCase for optional With* methods; skip null optional params in tests; reformatted long calls
• Kotlin: Handle null params in test request generation; handle nullable required fields (? = null)
• Scala: Handle null params in test request generation
• Swift: Emit nil for null values outside client tests

[algolia-bot]

✔️ Code generated!

Name	Link
🪓 Triggered by	40fc09b375100ab24caf0234d40ad0dc0e2a1115
🍃 Generated commit	090dfb664d466f4abbb7b8a149c6d8425e9a7678
🌲 Generated branch	generated/fix/templates

📊 Benchmark results

Benchmarks performed on the method using a mock server, the results might not reflect the real-world performance.

Language	Req/s
go	2967
swift	561
scala	23

[MarioAlexandruDan]

Found this:

• param_optional.mustache wraps null values in Some(...) instead of emitting None.
• Why it this a problem: In Scala, Some(null) means "field is present with a null value" and serializes as "criticalThreshold": null in the JSON body. The correct behavior for an optional null field is None, which omits the field from the body entirely.
• Location: templates/scala/tests/param_optional.mustache
• Solution: Add a null check at the top — when isNull is true, short-circuit to None (optional) or null (required) instead of going through the Some(...) wrapping:

  {{#isNull}}{{^required}}None{{/required}}{{#required}}{{>                                                                                                                                                                                                                                                      
  tests/param_value}}{{/required}}{{/isNull}}{{^isNull}}{{^required}}{{^isHelper}}Some({{/isHelper}}{{#isHelper}}{{^hasDefaultValue}}Some({{/hasDefaultValue}}{{#hasDefaultValue}}{{^isRoot}}Some({{/isRoot}}{{/hasDefaultValue}}{{/isHelper}}{{/required}}{{>                                                   
  tests/param_value}}{{^required}}{{^isHelper}}){{/isHelper}}{{#isHelper}}{{^hasDefaultValue}}){{/hasDefaultValue}}{{#hasDefaultValue}}{{^isRoot}}){{/isRoot}}{{/hasDefaultValue}}{{/isHelper}}{{/required}}{{/isNull}}

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

_{TIP This summary will be updated as you push new changes.}

[Fluf22]

@MarioAlexandruDan the goal here is to be able to send a literal null value to the API, compared to just not sending the field, which is not the same behavior