fix(types): emit working serde codecs for time::Date / time::Time (#25)

.beads/issues.jsonl

@@ -1,4 +1,6 @@
+{"id":"openapi-generator-5q8","title":"DateStrategy::Time emits broken serde codec for time::Date/time::Time (GH #25)","description":"GitHub issue gpu-cli/openapi-to-rust#25: fields with format: date/time under DateStrategy::Time get #[serde(with = \"time::serde::iso8601\")], but that module only supports OffsetDateTime — generated code fails to compile. Fix: emit time::serde::format_description! helper codec modules (time_date_format / time_time_format) into generated code, and correct the time dep requirement features (serde alone doesn't even enable rfc3339).","notes":"Fixed in PR https://github.com/gpu-cli/openapi-to-rust/pull/26 (branch worktree-issue-25-time-date-serde). Close when PR merges.","status":"in_progress","priority":1,"issue_type":"bug","assignee":"James Lal","owner":"james@littlebearlabs.io","created_at":"2026-07-11T18:36:28Z","created_by":"James Lal","updated_at":"2026-07-11T18:49:02Z","started_at":"2026-07-11T18:36:45Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"id":"openapi-generator-dpd","title":"Hybrid string-or-object discriminated unions deserialize-fail","description":"When an anyOf/oneOf union contains a discriminator AND a non-object branch (e.g. string-enum like ToolChoiceOptions), the generator emits a tagged enum that cannot deserialize the string form. Real-world hit: OpenAI ToolChoiceParam returns 'auto' in Response.tool_choice, but generated type is #[serde(tag=\"type\")] enum with no untagged String variant. Need to fall back to #[serde(untagged)] when the union mixes string/scalar branches with tagged-object branches, OR add a String fallback variant before the tagged variants.","notes":"Live repro: `ToolChoiceParam` from openai.yaml line 52518. anyOf has 8 branches; the first (`ToolChoiceOptions`) is a string-enum (\"none\"|\"auto\"|\"required\"), the rest are objects with discriminator propertyName=type. Generator emits `#[serde(tag=\"type\")] enum ToolChoiceParam { ToolChoiceOptions(ToolChoiceOptions), ... }` which cannot deserialize the string \"auto\" because serde tries to read a \"type\" field from a JSON string. Fix: when an anyOf/oneOf branch is a non-object schema (string/number/etc), the generator must emit `#[serde(untagged)]` with the scalar branch first OR add a String variant before the tagged variants. Hit on real OpenAI Responses API `Response.tool_choice` field.","status":"closed","priority":1,"issue_type":"bug","assignee":"James Lal","owner":"james@littlebearlabs.io","created_at":"2026-05-10T23:47:35Z","created_by":"James Lal","updated_at":"2026-05-11T00:12:46Z","started_at":"2026-05-10T23:54:10Z","closed_at":"2026-05-11T00:12:46Z","close_reason":"Fixed in src/analysis.rs: (dpd) analyze_oneof_union now downgrades to untagged when any branch is non-object — verified live against OpenAI Response.tool_choice='auto' which now deserializes as ToolChoiceParam::ToolChoiceOptions(Auto). (bgo) merge_schema_into_properties now ORs in is_nullable_pattern() for allOf-merged props — verified live against OpenAI Response.incomplete_details which is now Option\u003cResponseIncompleteDetails\u003e and deserializes null cleanly. All 4 smoke tests (OpenAI+Anthropic, sync+stream) pass.","dependency_count":0,"dependent_count":0,"comment_count":0}
+{"id":"openapi-generator-cwd","title":"Config docs say [generator.types] but parser reads top-level [types] — documented block is silently ignored","description":"README (§'[generator.types] — typed-scalar strategy per format', also [generator.types.strategies]) and the doc comment on ConfigFile::types say the type-mapping block lives at [generator.types], but ConfigFile deserializes it from top-level [types]. A TOML file using the documented path is silently ignored (unknown fields aren't denied), so users think they enabled e.g. date = \"time\" but get chrono defaults. Found while testing GH #25. Fix: either move the field under GeneratorSection or fix README + doc comment, and consider deny_unknown_fields or a validation warning.","status":"open","priority":2,"issue_type":"bug","owner":"james@littlebearlabs.io","created_at":"2026-07-11T18:47:50Z","created_by":"James Lal","updated_at":"2026-07-11T18:47:50Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"id":"openapi-generator-k07","title":"[bug] Query/path parameters ignore integer/number format (int32 -\u003e i64)","description":"analyze_parameter in src/analysis.rs hardcodes Integer =\u003e i64 and Number =\u003e f64, ignoring the schema format field. Body/schema properties correctly route through TypeMapper::integer_format/number_format, so int32 becomes i32 there, but the same format on a query/path parameter always yields i64. No type_mappings/strategies config can override it because analyze_parameter never calls TypeMapper. Fixes GitHub issue #23.","notes":"Fix in PR #24 (gpu-cli/openapi-to-rust), branch worktree-fix-i32-param-format. Root cause: analyze_parameter hardcoded Integer=\u003ei64 / Number=\u003ef64, bypassing TypeMapper. Now routes through integer_format/number_format. CI green (test/clippy/fmt/doc/spec-compile). Commented on GH issue #23. Awaiting review/merge.","status":"closed","priority":2,"issue_type":"bug","assignee":"James Lal","owner":"james@littlebearlabs.io","created_at":"2026-07-11T03:12:09Z","created_by":"James Lal","updated_at":"2026-07-11T03:29:45Z","started_at":"2026-07-11T03:12:21Z","closed_at":"2026-07-11T03:29:45Z","close_reason":"Fixed in PR #24, merged to main, released as v0.5.2 (crates.io + GitHub release). GH issue #23 commented.","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"id":"openapi-generator-76h","title":"Add ByteStrategy::Base64UrlUnpadded for format: byte","description":"Add a new ByteStrategy variant emitting RFC 7515 §2 url-safe unpadded base64 in the inlined base64_serde helper. Needed by gpu-cli portal-schema work (JWK/DPoP thumbprints, sealing pubkeys) so format: byte fields can round-trip without falling back to plain String + spec-side documentation. Spec-global config knob, not per-field.","status":"closed","priority":2,"issue_type":"feature","assignee":"James Lal","owner":"james@littlebearlabs.io","created_at":"2026-05-16T17:58:36Z","created_by":"James Lal","updated_at":"2026-05-16T18:29:10Z","started_at":"2026-05-16T17:58:50Z","closed_at":"2026-05-16T18:29:10Z","close_reason":"Shipped on worktree-base64url-unpadded (commit afc8c88). 16 typed_scalars_test, 23 type_mapping unit tests, 51-binary cargo test suite all green; clippy --lib clean.","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"id":"openapi-generator-9ek","title":"[Server P6] Snapshot tests + integration smoke test against openai.yaml","description":"End-to-end validation of server codegen.\n\nSnapshot coverage:\n- createChatCompletion alone (canonical case, both non-streaming and SSE variants)\n- createEmbedding alone (single non-streaming op, different tag)\n- tag:Files (multi-op single tag)\n- Mixed: createChatCompletion + tag:Embeddings (multi-tag router)\n\nFor each: snapshot the full generated tree (server/api.rs, server/router.rs, server/errors.rs, models.rs).\n\nIntegration smoke test:\n- Compile a small consumer crate under tests/conformance/server/ that has a hand-written impl ChatApi for TestState returning canned responses.\n- Boot the router on a random port via tokio::spawn.\n- Hit POST /v1/chat/completions with a sample body, assert response shape.\n- Hit with stream=true, assert SSE event sequence.\n\nDoc updates:\n- README section 'Server codegen' with the 3-command DevX loop (list → add → generate).\n- Example in examples/openai_server.rs showing the user-side impl + main().","design":"Tests live alongside existing snapshot tests. Snapshots in src/snapshots/. Integration test uses reqwest (already a dep) to hit the in-process server.","acceptance_criteria":"- [ ] insta snapshots for all four scenarios above, reviewed and accepted.\n- [ ] Integration smoke test passes in CI.\n- [ ] Regenerating after a spec rename produces a clear error (manually tested).\n- [ ] README and example present.","notes":"Canonical test cases (per user direction 2026-05-10):\n- OpenAI Responses API: operationId 'createResponse' in specs/openai.yaml (POST /v1/responses). Streaming via stream:true in body.\n- Anthropic Messages API: operationId 'messages_post' in specs/anthropic.yaml (POST /v1/messages). Streaming via stream:true in body.\n\nBoth are the production drivers for server codegen — every phase should keep these two working as the bar for 'done'.","status":"open","priority":2,"issue_type":"task","owner":"james@littlebearlabs.io","created_at":"2026-05-11T01:00:24Z","created_by":"James Lal","updated_at":"2026-05-11T01:44:50Z","dependencies":[{"issue_id":"openapi-generator-9ek","depends_on_id":"openapi-generator-cdx","type":"blocks","created_at":"2026-05-10T19:00:37Z","created_by":"James Lal","metadata":"{}"}],"dependency_count":1,"dependent_count":1,"comment_count":0}

src/generator.rs

@@ -460,6 +460,47 @@ impl CodeGenerator {
             TokenStream::new()
         };
 
+        // `time::Date` / `time::Time` have no built-in serde codec
+        // in the `time` crate (`time::serde::iso8601` is
+        // OffsetDateTime-only — GH #25), so declare one per type via
+        // the `format_description!` macro. It expands to a module
+        // (with an `::option` submodule) referenced from fields as
+        // `#[serde(with = "time_date_format")]` etc.
+        let time_date_helper = if analysis
+            .used_type_features
+            .contains(crate::type_mapping::TypeFeature::TimeDate)
+        {
+            quote! {
+                time::serde::format_description!(
+                    time_date_format,
+                    Date,
+                    "[year]-[month]-[day]"
+                );
+            }
+        } else {
+            TokenStream::new()
+        };
+
+        // RFC 3339 partial-time. `[optional [...]]` groups always
+        // format their contents, so whole seconds serialize with a
+        // trailing ".0" — in exchange, parsing accepts inputs both
+        // with and without fractional seconds.
+        let time_time_helper = if analysis
+            .used_type_features
+            .contains(crate::type_mapping::TypeFeature::TimeTime)
+        {
+            quote! {
+                time::serde::format_description!(
+                    version = 2,
+                    time_time_format,
+                    Time,
+                    "[hour]:[minute]:[second][optional [.[subsecond]]]"
+                );
+            }
+        } else {
+            TokenStream::new()
+        };
+
         // Generate file with imports and types (no module wrapper).
         let generated = quote! {
             //! Generated types from OpenAPI specification
@@ -476,6 +517,10 @@ impl CodeGenerator {
 
             #base64_helper
 
+            #time_date_helper
+
+            #time_time_helper
+
             #type_definitions
         };
 
@@ -1888,6 +1933,13 @@ impl CodeGenerator {
                 codec.clone()
             };
             attrs.push(quote! { with = #codec_path });
+            // A `with` codec disables serde's implicit
+            // missing-field → None handling for Option fields
+            // (serde-rs/serde#2878); without `default` a request
+            // that simply omits the field fails to deserialize.
+            if is_option_wrapped {
+                attrs.push(quote! { default });
+            }
         }
 
         if attrs.is_empty() {

src/type_mapping.rs

@@ -87,6 +87,13 @@ impl MappedType {
 pub enum TypeFeature {
     Chrono,
     Time,
+    /// `time::Date` via the generated `time_date_format` codec.
+    /// Tracked separately from [`TypeFeature::Time`] so the
+    /// generator only emits the `time::serde::format_description!`
+    /// helper when a `format: date` field actually exists.
+    TimeDate,
+    /// `time::Time` via the generated `time_time_format` codec.
+    TimeTime,
     Iso8601,
     Uuid,
     Bytes,
@@ -102,7 +109,22 @@ impl TypeFeature {
     pub fn dep_requirement(self) -> DepRequirement {
         match self {
             Self::Chrono => DepRequirement::new("chrono", "0.4").with_features(&["serde"]),
-            Self::Time => DepRequirement::new("time", "0.3").with_features(&["serde"]),
+            // `serde` alone doesn't enable `time::serde::rfc3339`;
+            // the codec modules are gated on formatting/parsing.
+            Self::Time => DepRequirement::new("time", "0.3").with_features(&[
+                "serde",
+                "formatting",
+                "parsing",
+            ]),
+            // `macros` on top: Date/Time have no built-in serde
+            // codec, so the generated code declares one via
+            // `time::serde::format_description!`.
+            Self::TimeDate | Self::TimeTime => DepRequirement::new("time", "0.3").with_features(&[
+                "serde",
+                "formatting",
+                "parsing",
+                "macros",
+            ]),
             Self::Iso8601 => DepRequirement::new("iso8601", "0.6"),
             Self::Uuid => DepRequirement::new("uuid", "1").with_features(&["serde", "v4"]),
             Self::Bytes => DepRequirement::new("bytes", "1").with_features(&["serde"]),
@@ -189,8 +211,23 @@ pub fn render_required_deps_toml(deps: &[DepRequirement]) -> Option<String> {
 pub fn collect_dep_requirements(used: &UsedFeatures) -> Vec<DepRequirement> {
     let mut deps: Vec<DepRequirement> = used.iter().map(|f| f.dep_requirement()).collect();
     deps.sort_by_key(|d| d.crate_name);
-    deps.dedup_by_key(|d| d.crate_name);
-    deps
+    // Several features can point at the same crate with different
+    // feature lists (e.g. Time vs TimeDate both need `time`); union
+    // the features so the single emitted line satisfies all of them.
+    let mut merged: Vec<DepRequirement> = Vec::new();
+    for dep in deps {
+        match merged.last_mut() {
+            Some(last) if last.crate_name == dep.crate_name => {
+                for feat in dep.features {
+                    if !last.features.contains(&feat) {
+                        last.features.push(feat);
+                    }
+                }
+            }
+            _ => merged.push(dep),
+        }
+    }
+    merged
 }
 
 /// Tracks which optional crates the generator emitted code for.
@@ -655,8 +692,12 @@ impl TypeMapper {
                 MappedType::with_feature("chrono::NaiveDate", TypeFeature::Chrono)
             }
             DateStrategy::Time => {
-                self.record(TypeFeature::Time);
-                MappedType::with_codec("time::Date", "time::serde::iso8601", TypeFeature::Time)
+                self.record(TypeFeature::TimeDate);
+                // `time::serde::iso8601` only supports
+                // OffsetDateTime; `time_date_format` is a codec
+                // module the generator emits into the file via
+                // `time::serde::format_description!` (GH #25).
+                MappedType::with_codec("time::Date", "time_date_format", TypeFeature::TimeDate)
             }
         }
     }
@@ -669,8 +710,10 @@ impl TypeMapper {
                 MappedType::with_feature("chrono::NaiveTime", TypeFeature::Chrono)
             }
             DateStrategy::Time => {
-                self.record(TypeFeature::Time);
-                MappedType::with_codec("time::Time", "time::serde::iso8601", TypeFeature::Time)
+                self.record(TypeFeature::TimeTime);
+                // Same story as `time::Date`: no built-in codec, so
+                // the generator emits `time_time_format`.
+                MappedType::with_codec("time::Time", "time_time_format", TypeFeature::TimeTime)
             }
         }
     }