Feat: (Rust) Added chrono (date/date-time) support for Rust Generator [resolves #19319]

[richy1623]

Current issue:

The rust generator does not use a typed Date/DateTime object, it uses a type String [resolves #19319]

Proposed solution

Use a common date time library chrono to represent these types

Implementation

• Added a new CLI option (useChrono) which defaults to true
• If this property is set use the new chrono types for the fields typeMapping
• If at least one field is using a Date or DateTime then include chrono as a dependency in the Cargo.toml

Testing

• Updated the tests to now expect a new dependency chrono where relevant
• Added a new test config for the option of useChrono=false and the expected behaviour is using String types

Requesting a review from one of the Rust technical comittee:

• @frol
• @farcaller
• @richardwhiuk
• @paladinzh
• @jacob-pro
• @dsteeley

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---

Summary by cubic

Adds typed date/time support in the Rust generator using chrono. By default, date maps to chrono::NaiveDate and date-time maps to chrono::DateTime<chrono::FixedOffset> to improve type safety and RFC3339 serialization. Resolves #19319.

• New Features

  • Map date -> chrono::NaiveDate, date-time -> chrono::DateTime<chrono::FixedOffset> when useChrono=true.
  • New option useChrono (CLI/config), default true; false keeps String.
  • Add chrono in generated Cargo.toml only when date fields are present.
  • Documented useChrono in Rust generator docs; added rust-reqwest-petstore-no-chrono config and sample.

• Migration

  • No changes for most users; chrono is added automatically when models use dates.
  • To keep legacy String dates, set useChrono=false (e.g., -p useChrono=false).

^{Written for commit a522e3e. Summary will update on new commits.}

[cubic-dev-ai]

8 issues found across 111 files

Note: This PR contains a large number of files. cubic only reviews up to 75 files per PR, so some files may not have been reviewed.

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="samples/client/petstore/rust/hyper/petstore/src/models/order.rs">

<violation number="1" location="samples/client/petstore/rust/hyper/petstore/src/models/order.rs:24">
P2: `ship_date` uses timezone-naive `NaiveDateTime` for an OpenAPI `date-time` field, risking RFC3339 offset incompatibility and loss of timezone semantics.</violation>
</file>

<file name="samples/client/petstore/rust/reqwest/petstore-avoid-box/docs/Order.md">

<violation number="1" location="samples/client/petstore/rust/reqwest/petstore-avoid-box/docs/Order.md:10">
P1: `date-time` is mapped to timezone-naive `chrono::NaiveDateTime`, which can drop or reject RFC3339 offset information for `ship_date`.</violation>
</file>

<file name="samples/client/petstore/rust/reqwest/petstore-no-chrono/git_push.sh">

<violation number="1" location="samples/client/petstore/rust/reqwest/petstore-no-chrono/git_push.sh:57">
P2: `git push` is piped through `grep`, which can hide the real push exit code and return incorrect script success/failure.</violation>
</file>

<file name="samples/client/petstore/rust/reqwest/petstore-no-chrono/src/apis/testing_api.rs">

<violation number="1" location="samples/client/petstore/rust/reqwest/petstore-no-chrono/src/apis/testing_api.rs:81">
P2: `Result<String, ...>` success handling incorrectly rejects `text/plain` responses instead of returning the response text.</violation>
</file>

<file name="samples/client/petstore/rust/reqwest/petstore-no-chrono/docs/TestingApi.md">

<violation number="1" location="samples/client/petstore/rust/reqwest/petstore-no-chrono/docs/TestingApi.md:54">
P2: Dead markdown link: `std::path::PathBuf` is linked to `std::path::PathBuf.md`, but that file is not present in the docs directory.</violation>
</file>

<file name="samples/client/petstore/rust/hyper/petstore/docs/Order.md">

<violation number="1" location="samples/client/petstore/rust/hyper/petstore/docs/Order.md:10">
P2: `date-time` is documented and modeled as `chrono::NaiveDateTime`, which is timezone-naive and can break or degrade RFC3339 offset semantics.</violation>
</file>

<file name="samples/client/petstore/rust/reqwest/petstore-no-chrono/src/apis/mod.rs">

<violation number="1" location="samples/client/petstore/rust/reqwest/petstore-no-chrono/src/apis/mod.rs:104">
P2: Content-Type detection is case-sensitive, so valid mixed-case JSON/text media types can be misclassified as unsupported and break response parsing.</violation>
</file>

<file name="samples/client/petstore/rust/reqwest/petstore-async-middleware/src/models/order.rs">

<violation number="1" location="samples/client/petstore/rust/reqwest/petstore-async-middleware/src/models/order.rs:24">
P2: `shipDate` uses `NaiveDateTime`, which is timezone-naive and can break RFC3339 `date-time` compatibility (offset parsing/round-tripping).</violation>
</file>

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

[cubic-dev-ai]

P2: Result<String, ...> success handling incorrectly rejects text/plain responses instead of returning the response text.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At samples/client/petstore/rust/reqwest/petstore-no-chrono/src/apis/testing_api.rs, line 81:

<comment>`Result<String, ...>` success handling incorrectly rejects `text/plain` responses instead of returning the response text.</comment>

<file context>
@@ -0,0 +1,225 @@
+        let content = resp.text()?;
+        match content_type {
+            ContentType::Json => serde_json::from_str(&content).map_err(Error::from),
+            ContentType::Text => return Err(Error::from(serde_json::Error::custom("Received `text/plain` content type response that cannot be converted to `String`"))),
+            ContentType::Unsupported(unknown_type) => return Err(Error::from(serde_json::Error::custom(format!("Received `{unknown_type}` content type response that cannot be converted to `String`")))),
+        }
</file context>

[richy1623]

this is generated by the generate-samples.sh script

[cubic-dev-ai]

P2: Content-Type detection is case-sensitive, so valid mixed-case JSON/text media types can be misclassified as unsupported and break response parsing.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At samples/client/petstore/rust/reqwest/petstore-no-chrono/src/apis/mod.rs, line 104:

<comment>Content-Type detection is case-sensitive, so valid mixed-case JSON/text media types can be misclassified as unsupported and break response parsing.</comment>

<file context>
@@ -0,0 +1,120 @@
+
+impl From<&str> for ContentType {
+    fn from(content_type: &str) -> Self {
+        if content_type.starts_with("application") && content_type.contains("json") {
+            return Self::Json;
+        } else if content_type.starts_with("text/plain") {
</file context>

[richy1623]

this is generated by the generate-samples.sh script