[scala-sttp4-jsoniter] extend Primitive type with UUID, LocalDate and OffsetDateTime

[reynaldjoabet]

Extend the Primitive union type in helpers.mustache with UUID,
LocalDate, and OffsetDateTime so that path, query, header, cookie, and
form parameters typed with these formats serialize via .toString() on the
fast primitive path. Without this, fields generated from format: uuid,
format: date, and format: date-time fall through to the Mirror-based
object path and fail at compile time because they are not products or sums.

@lbialy @flsh86

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

  (For Windows users, please run the script in WSL)
  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
  IMPORTANT: Do NOT purge/delete any folders/files (e.g. tests) when regenerating the samples as manually written tests may be removed.
• File the PR against the correct branch: master (upcoming 7.x.0 minor release - breaking changes with fallbacks), 8.0.x (breaking changes without fallbacks)
• If your PR solves a reported issue, reference it using GitHub's linking syntax (e.g., having "fixes #123" present in the PR description)
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

---

Summary by cubic

Extended Primitive in scala-sttp4-jsoniter to include UUID, LocalDate, and OffsetDateTime, enabling fast-path .toString() serialization for uuid, date, and date-time params. This removes the Mirror fallback and fixes compile errors in generated clients.

• Bug Fixes
  • Path, query, header, cookie, and form params with these formats now serialize as primitives and compile.
  • Updated petstore sample to reflect the new Primitive union.

^{Written for commit 95ad1f8. Summary will update on new commits. Review in cubic}

[cubic-dev-ai]

No issues found across 2 files

_{Re-trigger cubic}

[wing328]

thanks for the PR

cc @clasnake (2017/07), @shijinkui (2018/01), @ramzimaalej (2018/03), @chameleon82 (2020/03), @Bouillie (2020/04) @Fish86 (2023/06)

[wing328]

@reynaldjoabet are you using this change in your production environment to confirm it works for your use cases?

[wing328]

Is there a minimal spec to easily reproduce the issue and confirm the fix?

That will help speed up the review and get it merged sooner

[reynaldjoabet]

Is there a minimal spec to easily reproduce the issue and confirm the fix?

Yes. Three single-parameter snippets, each one independently reproduces a failure on the current master:

1. format: uuid on a header

parameters:
  - name: x-fapi-interaction-id
    in: header
    required: true
    schema:
      type: string
      format: uuid

.headers(HeaderSerializable.serialize("x-fapi-interaction-id", xFapiInteractionId, false))
[error] No given instance of type scala.deriving.Mirror.Of[java.util.UUID] was found.
[error] Failed to synthesize an instance of type scala.deriving.Mirror.Of[java.util.UUID]:
[error]   * class UUID is not a generic product because it is not a case class
[error]   * class UUID is not a generic sum because it is not a sealed class

2. format: date-time on a header

parameters:
  - name: x-fapi-auth-date
    in: header
    required: false
    schema:
      type: string
      format: date-time

.headers(HeaderSerializable.serialize("x-fapi-auth-date", xFapiAuthDate, false))
[error] No given instance of type scala.deriving.Mirror.Of[java.time.OffsetDateTime] was found.
[error] Failed to synthesize an instance of type scala.deriving.Mirror.Of[java.time.OffsetDateTime]:
[error]   * class OffsetDateTime is not a generic product because it is not a case class
[error]   * class OffsetDateTime is not a generic sum because it is not a sealed class

3. format: date on a query parameter

parameters:
  - name: fromBookingDate
    in: query
    schema:
      type: string
      format: date

.addParams(FormSerializable.serialize("fromBookingDate", fromBookingDate, FormStyleFormat.FORM, true): _*)
[error] No given instance of type scala.deriving.Mirror.Of[java.time.LocalDate] was found.
[error] Failed to synthesize an instance of type scala.deriving.Mirror.Of[java.time.LocalDate]:
[error]   * class LocalDate is not a generic product because it is not a case class
[error]   * class LocalDate is not a generic sum because it is not a sealed class

Root cause

helpers.mustache declares:

type Primitive = String | Short | Int | Long | Float | Double | BigDecimal | Boolean

but the generator emits UUID / OffsetDateTime / LocalDate for the three formats above. The inline match falls through to the summonInline[Mirror.Of[T]] branch, which can't synthesize a Mirror for a Java class.