Add support for enums of integers in rust-server generator.

[dsteeley]

Support enums of integers in rust-server generator. Previously we treated all enum values as strings which in some cases may be incorrect and result in being unable to deserialise an integer enum value.

Elements in an enum array can be any time according to 5.20 of the json schema which the openapi specification inherits for enum types. https://datatracker.ietf.org/doc/html/[draft-wright-json-schema-validation-00](https://datatracker.ietf.org/doc/html/draft-wright-json-schema-validation-00#section-5.20)#section-5.20.

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---

Summary by cubic

Add support for integer enums in the rust-server generator using serde_repr so they serialize/deserialize as JSON numbers. Also fixes header conversion impls in deprecated templates to work in client builds.

• Bug Fixes
  • Detect integer enums and set vendor extensions with the correct Rust repr; include serde_repr in Cargo only when needed.
  • Update models.mustache to derive Serialize_repr/Deserialize_repr and apply #[repr()]; string enums keep existing serde behavior.
  • Expose Vec header TryFrom impls for both client and server in rust-server-deprecated templates.

^{Written for commit 171d779. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 3 files

[cubic-dev-ai]

6 issues found across 15 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="samples/server/petstore/rust-server/output/multipart-v3/src/models.rs">

<violation number="1" location="samples/server/petstore/rust-server/output/multipart-v3/src/models.rs:169">
P2: List header parsing now requires a comma+space delimiter, which rejects valid list headers without whitespace (e.g., "a,b") and can cause parsing failures. HTTP list headers allow optional whitespace around commas, so the split should accept commas regardless of spaces.</violation>
</file>

<file name="samples/server/petstore/rust-server/output/petstore-with-fake-endpoints-models-for-testing/src/models.rs">

<violation number="1" location="samples/server/petstore/rust-server/output/petstore-with-fake-endpoints-models-for-testing/src/models.rs:158">
P2: Header Vec parsing now splits only on the exact ", " delimiter, so valid comma-separated header values like "a,b" or "a,  b" are not parsed into elements. This is a regression from the previous `.split(',')` behavior and can cause deserialization errors for standard header formats.</violation>
</file>

<file name="samples/server/petstore/rust-server/output/rust-server-test/src/models.rs">

<violation number="1" location="samples/server/petstore/rust-server/output/rust-server-test/src/models.rs:165">
P2: Header list parsing now requires a comma+space delimiter. Valid HTTP header lists can be comma-separated without spaces ("a,b"), so .split(", ") will treat them as a single entry and can break parsing. Use ',' as the delimiter and keep trimming each element to accept both forms.</violation>
</file>

<file name="modules/openapi-generator/src/main/resources/rust-server/models.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/rust-server/models.mustache:686">
P2: Header list parsing now only splits on comma+space, rejecting valid header values like "a,b" (HTTP lists allow optional whitespace). This will cause enum list headers without spaces to fail parsing. Split on ',' and trim instead.</violation>
</file>

<file name="samples/server/petstore/rust-server/output/no-example-v3/src/models.rs">

<violation number="1" location="samples/server/petstore/rust-server/output/no-example-v3/src/models.rs:149">
P2: Header list parser now only splits on comma+space, rejecting valid comma-separated headers without spaces.</violation>
</file>

<file name="samples/server/petstore/rust-server/output/openapi-v3/src/models.rs">

<violation number="1" location="samples/server/petstore/rust-server/output/openapi-v3/src/models.rs:121">
P2: List header parsing now splits on ", " only, so valid header values without a space after the comma (e.g., "a,b") won't be split into multiple items and can be parsed incorrectly. Use a comma-only split and rely on trim() to handle optional whitespace.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[dsteeley]

@wing328 This PR is ready for attention.