# Blueprint serialization & loader (cycle 0087) — Implementation Plan > **Parent spec:** `docs/specs/0087-blueprint-serialization-loader.md` > > **For agentic workers:** REQUIRED SUB-SKILL: use the `implement` skill to run > this plan. Steps use `- [ ]` checkboxes for tracking. **Goal:** Close the C24 graph-as-data loop (#155): a canonical, versioned serialization of a param-generic `Composite` blueprint plus a `data → blueprint` loader, so a serialized blueprint runs bit-identical (C1) to its Rust-built twin. **Architecture:** A serde DTO layer in a new `aura-engine` module projects a `&Composite` to canonical JSON (the build closures dropped) and reconstructs it through an **injected** node resolver; the concrete closed `match` over the `aura-std` vocabulary lives in `aura-std` (the engine never depends on the node vocabulary crate — its only library deps are `aura-core` + `aura-analysis` + serde; `aura-std` is a test-only dep). Sinks and structural-construction-arg nodes are out of the round-trippable set (see spec; recorded on #155). **Tech Stack:** `serde` + `serde_json` (both already deps of `aura-engine`; `serde` derive already in `aura-core`), the existing `Composite` / `PrimitiveBuilder` / `compile_with_params` machinery. --- **Files this plan creates or modifies:** - Modify: `crates/aura-core/src/scalar.rs:14` — add serde derive to `ScalarKind` - Modify: `crates/aura-core/src/node.rs:91` — add serde derive to `BoundParam` - Modify: `crates/aura-engine/src/harness.rs:29,38` — add serde derive to `Edge`, `Target` - Modify: `crates/aura-engine/src/blueprint.rs:29,126` — add serde derive to `OutField`, `Role` (`source` skip-when-None) - Create: `crates/aura-std/src/vocabulary.rs` — `std_vocabulary(type_id)` closed match (22 zero-arg builders) - Modify: `crates/aura-std/src/lib.rs` — `mod vocabulary;` + `pub use vocabulary::std_vocabulary;` - Create: `crates/aura-engine/src/blueprint_serde.rs` — DTOs, `BLUEPRINT_FORMAT_VERSION`, `blueprint_to_json`, `blueprint_from_json`, `SerializeError`, `LoadError` - Modify: `crates/aura-engine/src/lib.rs:45-79` — `mod blueprint_serde;` + re-exports - Modify: `crates/aura-engine/src/test_fixtures.rs` — add `sink_free_sma_cross_signal()` fixture - Test: `crates/aura-core/src/scalar.rs` (tests) — `ScalarKind` serde = variant-name - Test: `crates/aura-std/src/vocabulary.rs` (tests) — resolver hits/misses - Test: `crates/aura-engine/src/blueprint_serde.rs` (tests) — canonical golden, named failures, bit-identical run, idempotence, recursion Note on the spec's type-list: `Firing` (spec Components table) is **not** in the serialized closure — the DTO carries only `type_id`/`name`/`bound`; `Firing` lives in `NodeSchema`/`PortSpec`, which are never serialized (schemas are re-derived from the resolver). It gets no serde derive. The spec also mis-locates `ScalarKind` in `node.rs`; it is in `scalar.rs:15`. --- ### Task 1: serde derives on the plain serialized types **Files:** - Modify: `crates/aura-core/src/scalar.rs:14` (`ScalarKind`), `crates/aura-core/src/node.rs:91` (`BoundParam`) - Modify: `crates/aura-engine/src/harness.rs:29` (`Edge`), `:38` (`Target`) - Modify: `crates/aura-engine/src/blueprint.rs:29` (`OutField`), `:126` (`Role`) - Test: `crates/aura-core/src/scalar.rs` (tests module) - [ ] **Step 1: Add the serde encoding test (RED)** In `crates/aura-core/src/scalar.rs`, inside the existing `#[cfg(test)] mod tests` block (the one holding `scalar_serde_round_trips`), add: ```rust #[test] fn scalar_kind_serde_is_variant_name() { // canonical kind encoding: a bare variant-name string, both directions. assert_eq!(serde_json::to_string(&ScalarKind::I64).unwrap(), "\"I64\""); assert_eq!(serde_json::to_string(&ScalarKind::F64).unwrap(), "\"F64\""); let back: ScalarKind = serde_json::from_str("\"I64\"").unwrap(); assert_eq!(back, ScalarKind::I64); } ``` - [ ] **Step 2: Run the test to verify it fails to compile** Run: `cargo test -p aura-core scalar_kind_serde_is_variant_name` Expected: FAIL — compile error, `ScalarKind` does not implement `Serialize`. - [ ] **Step 3: Add the derives** `crates/aura-core/src/scalar.rs:14` — change `#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]` (on `ScalarKind`) to: ```rust #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)] ``` `crates/aura-core/src/node.rs:91` — change `#[derive(Clone, Debug, PartialEq)]` (on `BoundParam`) to: ```rust #[derive(Clone, Debug, PartialEq, serde::Serialize, serde::Deserialize)] ``` `crates/aura-engine/src/harness.rs:29` (`Edge`) and `:38` (`Target`) — change each `#[derive(Clone, Copy, Debug, PartialEq, Eq)]` to: ```rust #[derive(Clone, Copy, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)] ``` `crates/aura-engine/src/blueprint.rs:29` (`OutField`) — change `#[derive(Clone, Debug, PartialEq, Eq)]` to: ```rust #[derive(Clone, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)] ``` `crates/aura-engine/src/blueprint.rs:126` (`Role`) — change `#[derive(Clone, Debug, PartialEq, Eq)]` to the line below, and add the field attribute on `source`: ```rust #[derive(Clone, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)] pub struct Role { pub name: String, pub targets: Vec, /// `None` = an open interior port (wired by the enclosing graph's edges); /// `Some(kind)` = a bound ingestion feed of `kind` (only meaningful at the root, /// where it lowers to a `FlatGraph` source). C3: sources bind at ingestion only. #[serde(default, skip_serializing_if = "Option::is_none")] pub source: Option, } ``` (Deriving serde directly on `Role` — rather than the spec's separate `RoleData` mirror — yields the identical wire bytes with one fewer type; the format is unchanged. `Edge`/`Target`/`OutField`/`BoundParam` likewise serialize 1:1, so the DTO embeds the real types.) - [ ] **Step 4: Run the test to verify it passes** Run: `cargo test -p aura-core scalar_kind_serde_is_variant_name` Expected: PASS. - [ ] **Step 5: Build the engine to confirm the engine-side derives compile** Run: `cargo build -p aura-engine` Expected: clean build (0 errors). --- ### Task 2: the closed aura-std node-vocabulary resolver **Files:** - Create: `crates/aura-std/src/vocabulary.rs` - Modify: `crates/aura-std/src/lib.rs` (`mod` list + `pub use` block) - [ ] **Step 1: Create `crates/aura-std/src/vocabulary.rs`** ```rust //! The closed, compiled-in dispatch from a serialized node **type identity** to //! its `aura-std` builder factory — the load-side counterpart to the type label //! a blueprint serializes (`PrimitiveBuilder::label`). This is **not** a dynamic //! registry (domain invariant 9): it is a `match` the crate that *owns* the //! nodes writes, over its own closed, compiled-in vocabulary (C24 — nodes are //! referenced "by compiled-in type identity", never a by-name marketplace). The //! engine cannot hold this table (it does not depend on `aura-std`); a loader //! takes it as an injected resolver, and a project `cdylib` later supplies its //! own (C16) through the same seam. //! //! Scope (#155): only the **zero-argument** `Type::builder()` factories are //! resolvable. Builders that take structural construction arguments //! (`LinComb(arity)`, `CostSum(n_costs)`, `SimBroker(pip_size)`, `Session(..)`) //! and the recording sinks (`Recorder`/`GatedRecorder`/`SeriesReducer`, which //! capture an `mpsc::Sender`) are deliberately absent — an absent `type_id` //! yields `None`, so the loader fails cleanly (`LoadError::UnknownNodeType`) //! rather than guessing. Serialising structural-axis construction args is a //! later, additive extension (#156/C20). use crate::{ Add, And, Bias, CarryCost, ConstantCost, Delay, Ema, EqConst, FixedStop, Gt, Latch, LongOnly, Mul, PositionManagement, Resample, RollingMax, RollingMin, Sizer, Sma, Sqrt, Sub, VolSlippageCost, }; use aura_core::PrimitiveBuilder; /// Resolve a serialized node type identity (the `PrimitiveBuilder::label`, e.g. /// `"SMA"`) to a fresh, unbound builder from the node's own factory. Returns /// `None` for any identity outside the zero-arg `aura-std` vocabulary. pub fn std_vocabulary(type_id: &str) -> Option { Some(match type_id { "Add" => Add::builder(), "And" => And::builder(), "Bias" => Bias::builder(), "CarryCost" => CarryCost::builder(), "ConstantCost" => ConstantCost::builder(), "Delay" => Delay::builder(), "EMA" => Ema::builder(), "EqConst" => EqConst::builder(), "FixedStop" => FixedStop::builder(), "Gt" => Gt::builder(), "Latch" => Latch::builder(), "LongOnly" => LongOnly::builder(), "Mul" => Mul::builder(), "PositionManagement" => PositionManagement::builder(), "Resample" => Resample::builder(), "RollingMax" => RollingMax::builder(), "RollingMin" => RollingMin::builder(), "Sizer" => Sizer::builder(), "SMA" => Sma::builder(), "Sqrt" => Sqrt::builder(), "Sub" => Sub::builder(), "VolSlippageCost" => VolSlippageCost::builder(), _ => return None, }) } #[cfg(test)] mod tests { use super::std_vocabulary; #[test] fn std_vocabulary_resolves_known_and_rejects_unknown() { // a known zero-arg node resolves, and the builder carries the type label back let sma = std_vocabulary("SMA").expect("SMA is in the vocabulary"); assert_eq!(sma.label(), "SMA"); // an unknown id, a construction-arg node, and a sink are all absent assert!(std_vocabulary("nope").is_none()); assert!(std_vocabulary("LinComb").is_none()); assert!(std_vocabulary("Recorder").is_none()); } } ``` - [ ] **Step 2: Wire the module into `crates/aura-std/src/lib.rs`** Add `mod vocabulary;` to the private `mod` list (after `mod vol_slippage_cost;`): ```rust mod vocabulary; ``` Add the re-export at the end of the `pub use` block (after `pub use vol_slippage_cost::VolSlippageCost;`): ```rust pub use vocabulary::std_vocabulary; ``` - [ ] **Step 3: Run the resolver test** Run: `cargo test -p aura-std std_vocabulary_resolves_known_and_rejects_unknown` Expected: PASS. --- ### Task 3: DTO layer + canonical serializer + envelope **Files:** - Create: `crates/aura-engine/src/blueprint_serde.rs` - Modify: `crates/aura-engine/src/lib.rs` (`mod` + re-export) - Modify: `crates/aura-engine/src/test_fixtures.rs` (add the sink-free signal fixture) - [ ] **Step 1: Add the sink-free signal fixture to `test_fixtures.rs`** Append to `crates/aura-engine/src/test_fixtures.rs` (its imports already cover `BlueprintNode`/`Composite`/`Edge`/`OutField`/`Role`/`Target`, `Scalar`, and `aura_std::{Bias, Sma, Sub}`): ```rust /// The SMA-cross **signal** graph as a sink-free, param-generic composite: fast /// SMA (length bound to 2) and slow SMA over one `price` role, their spread, a /// `Bias`. Output is the `bias` field. No recorder/broker — observation is /// attached by the caller. This is the canonical round-trip fixture (cycle 0087). pub(crate) fn sink_free_sma_cross_signal() -> Composite { Composite::new( "sma_cross", vec![ Sma::builder().named("fast").bind("length", Scalar::i64(2)).into(), Sma::builder().named("slow").into(), Sub::builder().into(), Bias::builder().into(), ], vec![ Edge { from: 0, to: 2, slot: 0, from_field: 0 }, // fast -> Sub slot 0 Edge { from: 1, to: 2, slot: 1, from_field: 0 }, // slow -> Sub slot 1 Edge { from: 2, to: 3, slot: 0, from_field: 0 }, // spread -> Bias ], vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }], vec![OutField { node: 3, field: 0, name: "bias".into() }], ) } ``` - [ ] **Step 2: Create `crates/aura-engine/src/blueprint_serde.rs` (DTO + serializer)** ```rust //! Blueprint serialization (C24): a `Composite` blueprint is projected to a //! canonical, versioned data value and reconstructed from it (`blueprint_from_json` //! in this module's loader half). `Composite`/`PrimitiveBuilder` cannot derive //! serde — they hold a `Box` build closure — so the format is a faithful //! serde **projection**: it carries each primitive's compiled-in **type identity** //! (`PrimitiveBuilder::label`), its instance name, and its bound params; the build //! closure and the declared schema are re-derived on load from the injected //! resolver. This is the inverse of the lossy render half (`model_to_json`); it //! carries no node logic (C17) and references a closed vocabulary (C24). use crate::blueprint::{BlueprintNode, Composite, OutField, Role}; use crate::harness::Edge; use aura_core::{BoundParam, PrimitiveBuilder}; /// The format version the loader understands. Bumped only by a load-bearing /// (Tier-2) change; additive optional fields do not bump it (#156). pub const BLUEPRINT_FORMAT_VERSION: u32 = 1; /// Top-level envelope: the version is read before the payload is interpreted. #[derive(serde::Serialize, serde::Deserialize)] pub struct BlueprintDoc { pub format_version: u32, pub blueprint: CompositeData, } /// Serde mirror of a `Composite` (the in-memory type holds build closures and /// cannot derive serde). Field order here is the canonical JSON field order. #[derive(serde::Serialize, serde::Deserialize)] pub struct CompositeData { pub name: String, pub nodes: Vec, #[serde(default, skip_serializing_if = "Vec::is_empty")] pub edges: Vec, #[serde(default, skip_serializing_if = "Vec::is_empty")] pub input_roles: Vec, #[serde(default, skip_serializing_if = "Vec::is_empty")] pub output: Vec, } /// A blueprint item: a primitive (referenced by type identity) or a nested /// composite (recursion). Externally tagged: `{"primitive": ..}` / `{"composite": ..}`. #[derive(serde::Serialize, serde::Deserialize)] #[serde(rename_all = "snake_case")] pub enum NodeData { Primitive(PrimitiveData), Composite(CompositeData), } /// A primitive node as data: its compiled-in type identity, optional instance /// name, and bound params. The schema + build closure are re-derived on load. #[derive(serde::Serialize, serde::Deserialize)] pub struct PrimitiveData { #[serde(rename = "type")] pub type_id: String, #[serde(default, skip_serializing_if = "Option::is_none")] pub name: Option, #[serde(default, skip_serializing_if = "Vec::is_empty")] pub bound: Vec, } /// Serializer failure (typed, named). #[derive(Debug)] pub enum SerializeError { Json(serde_json::Error), } fn project(c: &Composite) -> CompositeData { CompositeData { name: c.name().to_string(), nodes: c.nodes().iter().map(project_node).collect(), edges: c.edges().to_vec(), input_roles: c.input_roles().to_vec(), output: c.output().to_vec(), } } fn project_node(n: &BlueprintNode) -> NodeData { match n { BlueprintNode::Primitive(b) => NodeData::Primitive(PrimitiveData { type_id: b.label(), name: b.instance_name().map(str::to_string), bound: b.bound_params().to_vec(), }), BlueprintNode::Composite(c) => NodeData::Composite(project(c)), } } /// Serialize a blueprint to canonical, versioned JSON: compact, struct-declaration /// field order, defaults omitted (`skip_serializing_if`). An absent optional is /// byte-identical to the pre-extension form. pub fn blueprint_to_json(c: &Composite) -> Result { let doc = BlueprintDoc { format_version: BLUEPRINT_FORMAT_VERSION, blueprint: project(c) }; serde_json::to_string(&doc).map_err(SerializeError::Json) } #[cfg(test)] mod tests { use super::*; #[test] fn signal_serializes_to_canonical_golden() { let signal = crate::test_fixtures::sink_free_sma_cross_signal(); let json = blueprint_to_json(&signal).expect("serializes"); let golden = r#"{"format_version":1,"blueprint":{"name":"sma_cross","nodes":[{"primitive":{"type":"SMA","name":"fast","bound":[{"pos":0,"name":"length","kind":"I64","value":{"I64":2}}]}},{"primitive":{"type":"SMA","name":"slow"}},{"primitive":{"type":"Sub"}},{"primitive":{"type":"Bias"}}],"edges":[{"from":0,"to":2,"slot":0,"from_field":0},{"from":1,"to":2,"slot":1,"from_field":0},{"from":2,"to":3,"slot":0,"from_field":0}],"input_roles":[{"name":"price","targets":[{"node":0,"slot":0},{"node":1,"slot":0}]}],"output":[{"node":3,"field":0,"name":"bias"}]}}"#; // pins: canonical field order, format_version envelope, AND omit-defaults // (the unnamed/unbound `Sub` + `Bias` carry no `name`/`bound` keys; the // `price` role carries no `source` key). assert_eq!(json, golden); assert!(json.contains(r#"{"primitive":{"type":"Sub"}}"#), "omit-defaults"); } } ``` - [ ] **Step 3: Wire the module into `crates/aura-engine/src/lib.rs`** Add to the private `mod` list (around `:45-52`, next to `mod blueprint;`): ```rust mod blueprint_serde; ``` Add to the re-export block (around `:54-79`): ```rust pub use blueprint_serde::{blueprint_to_json, BlueprintDoc, CompositeData, NodeData, PrimitiveData, SerializeError, BLUEPRINT_FORMAT_VERSION}; ``` - [ ] **Step 4: Run the golden test** Run: `cargo test -p aura-engine signal_serializes_to_canonical_golden` Expected: PASS. --- ### Task 4: the loader + typed load errors **Files:** - Modify: `crates/aura-engine/src/blueprint_serde.rs` (add loader + `LoadError`) - Modify: `crates/aura-engine/src/lib.rs` (extend the re-export) - [ ] **Step 1: Add the loader + `LoadError` to `blueprint_serde.rs`** Append after `blueprint_to_json` (before the `#[cfg(test)]` module): ```rust /// Loader failure (typed, named — never a panic, never a silent wrong graph). #[derive(Debug)] pub enum LoadError { /// Malformed or structurally-invalid JSON. Json(serde_json::Error), /// `format_version` the loader does not understand. The full must-understand /// horizon (multiple versions, unknown-section policy) is #156; #155 supports /// exactly one version and refuses any other, cleanly. UnsupportedVersion { found: u32, supported: u32 }, /// `resolve` returned `None` for a serialized `type_id` (outside the injected /// vocabulary — unknown node, or a construction-arg/sink node not in #155's set). UnknownNodeType(String), } fn reconstruct( d: &CompositeData, resolve: &dyn Fn(&str) -> Option, ) -> Result { let mut nodes = Vec::with_capacity(d.nodes.len()); for nd in &d.nodes { nodes.push(match nd { NodeData::Primitive(p) => { let mut b = resolve(&p.type_id) .ok_or_else(|| LoadError::UnknownNodeType(p.type_id.clone()))?; if let Some(n) = &p.name { b = b.named(n); } // Re-apply bound params BY NAME. The effective param vector is // order-independent (each `bind` computes its slot against the // shrunk schema); ascending original `pos` is the canonical order. let mut bound: Vec<&BoundParam> = p.bound.iter().collect(); bound.sort_by_key(|bp| bp.pos); for bp in bound { b = b.bind(&bp.name, bp.value); } BlueprintNode::Primitive(b) } NodeData::Composite(c) => BlueprintNode::Composite(reconstruct(c, resolve)?), }); } Ok(Composite::new( d.name.clone(), nodes, d.edges.clone(), d.input_roles.clone(), d.output.clone(), )) } /// Load a blueprint from canonical JSON, resolving each primitive's type identity /// through the injected `resolve` (e.g. `aura_std::std_vocabulary`). The version /// envelope is checked before the payload is reconstructed. pub fn blueprint_from_json( data: &str, resolve: &dyn Fn(&str) -> Option, ) -> Result { let doc: BlueprintDoc = serde_json::from_str(data).map_err(LoadError::Json)?; if doc.format_version != BLUEPRINT_FORMAT_VERSION { return Err(LoadError::UnsupportedVersion { found: doc.format_version, supported: BLUEPRINT_FORMAT_VERSION, }); } reconstruct(&doc.blueprint, resolve) } ``` - [ ] **Step 2: Extend the `lib.rs` re-export** Change the Task-3 re-export line to add `blueprint_from_json` and `LoadError`: ```rust pub use blueprint_serde::{blueprint_from_json, blueprint_to_json, BlueprintDoc, CompositeData, LoadError, NodeData, PrimitiveData, SerializeError, BLUEPRINT_FORMAT_VERSION}; ``` - [ ] **Step 3: Add the named-failure tests** In `blueprint_serde.rs`'s `#[cfg(test)] mod tests`, add (the resolver `aura_std::std_vocabulary` is available — `aura-std` is a test-only dep of the engine): ```rust #[test] fn unknown_node_type_fails_named() { // a valid envelope naming a type outside the vocabulary -> clean, named error let json = r#"{"format_version":1,"blueprint":{"name":"x","nodes":[{"primitive":{"type":"NoSuchNode"}}]}}"#; let err = blueprint_from_json(json, &|t| aura_std::std_vocabulary(t)).unwrap_err(); assert!(matches!(err, LoadError::UnknownNodeType(t) if t == "NoSuchNode")); } #[test] fn unsupported_version_fails_named() { let json = r#"{"format_version":2,"blueprint":{"name":"x","nodes":[]}}"#; let err = blueprint_from_json(json, &|t| aura_std::std_vocabulary(t)).unwrap_err(); assert!(matches!(err, LoadError::UnsupportedVersion { found: 2, supported: 1 })); } ``` - [ ] **Step 4: Run the loader failure tests** Run: `cargo test -p aura-engine unknown_node_type_fails_named` Expected: PASS. Run: `cargo test -p aura-engine unsupported_version_fails_named` Expected: PASS. --- ### Task 5: round-trip integration — bit-identical run, idempotence, recursion **Files:** - Modify: `crates/aura-engine/src/blueprint_serde.rs` (`#[cfg(test)] mod tests`) - [ ] **Step 1: Add a recorder-attaching run helper + the bit-identical test** In `blueprint_serde.rs`'s `#[cfg(test)] mod tests`, add the imports and helper. The helper nests a signal composite under a root with one `Recorder` on its `bias` output (the same `Composite::new` nesting idiom as `composite_sma_cross_harness`), bootstraps with the open point, and returns the recorded trace: ```rust use crate::blueprint::{Composite, Role}; use crate::harness::{Edge, Target}; use crate::VecSource; // crate-root re-export (blueprint.rs tests import it the same way, e.g. :923) use aura_core::{Scalar, ScalarKind, Timestamp}; use aura_std::Recorder; use std::sync::mpsc; // Open param point for the sink-free signal (fast.length is bound): [slow.length, bias.scale]. fn signal_point() -> Vec { vec![Scalar::i64(4), Scalar::f64(0.5)] } // Nest `signal` under a root that records its single `bias` output, run the // 7-tick synthetic price fixture, and collect the recorded trace. fn run_recording(signal: Composite) -> Vec<(Timestamp, Vec)> { let (tx, rx) = mpsc::channel(); let root = Composite::new( "h", vec![ crate::blueprint::BlueprintNode::Composite(signal), Recorder::builder(vec![ScalarKind::F64], aura_core::Firing::Any, tx).into(), ], vec![Edge { from: 0, to: 1, slot: 0, from_field: 0 }], // bias -> recorder vec![Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }], // price -> nested signal's price port source: Some(ScalarKind::F64), }], vec![], ); let prices = crate::test_fixtures::synthetic_prices(); let mut h = root.bootstrap_with_params(signal_point()).expect("bootstraps"); h.run(vec![Box::new(VecSource::new(prices))]); rx.try_iter().collect() } #[test] fn serialized_blueprint_runs_bit_identical_to_rust_built() { let rust_built = crate::test_fixtures::sink_free_sma_cross_signal(); let json = blueprint_to_json(&rust_built).expect("serializes"); let loaded = blueprint_from_json(&json, &|t| aura_std::std_vocabulary(t)).expect("loads"); let trace_rust = run_recording(rust_built); let trace_loaded = run_recording(loaded); assert_eq!(trace_rust, trace_loaded, "serialized-then-loaded run diverged"); assert!(!trace_loaded.is_empty(), "trace must be populated (non-degenerate)"); } ``` - [ ] **Step 2: Run the bit-identical test** Run: `cargo test -p aura-engine serialized_blueprint_runs_bit_identical_to_rust_built` Expected: PASS. - [ ] **Step 3: Add the canonical-idempotence and recursion tests** In the same test module: ```rust #[test] fn serializer_and_loader_are_inverse() { let original = crate::test_fixtures::sink_free_sma_cross_signal(); let json = blueprint_to_json(&original).expect("serializes"); let loaded = blueprint_from_json(&json, &|t| aura_std::std_vocabulary(t)).expect("loads"); // serialize -> load -> serialize is byte-stable (canonical round-trip identity) assert_eq!(json, blueprint_to_json(&loaded).expect("re-serializes")); } #[test] fn nested_composite_round_trips() { // recursion + a nested bound param + a role: wrap the signal composite in // an outer composite that re-exports its `bias` output. Proves the loop is // not flat-SMA-specific. let inner = crate::test_fixtures::sink_free_sma_cross_signal(); let outer = Composite::new( "outer", vec![crate::blueprint::BlueprintNode::Composite(inner)], vec![], vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None, }], vec![crate::blueprint::OutField { node: 0, field: 0, name: "bias".into() }], ); let json = blueprint_to_json(&outer).expect("serializes"); let loaded = blueprint_from_json(&json, &|t| aura_std::std_vocabulary(t)).expect("loads"); assert_eq!(json, blueprint_to_json(&loaded).expect("re-serializes")); // the nested composite survived as a composite, not flattened assert!(json.contains(r#"{"composite":{"name":"sma_cross""#), "nested composite preserved"); } ``` - [ ] **Step 4: Run the idempotence + recursion tests** Run: `cargo test -p aura-engine serializer_and_loader_are_inverse` Expected: PASS. Run: `cargo test -p aura-engine nested_composite_round_trips` Expected: PASS. - [ ] **Step 5: Full workspace gate** Run: `cargo test --workspace` Expected: PASS (all pre-existing tests + the new cycle-0087 tests; ~737 + new). Run: `cargo clippy --workspace --all-targets -- -D warnings` Expected: clean (0 warnings).