---
phase: 51-yaml-parser-core
verified: 2026-04-18T18:00:00Z
status: passed
score: 5/5 must-haves verified
deferred:
  - truth: "The same define-time validation (graph validation, expression checks, DAG resolution) runs identically for YAML-originated and SQL-originated definitions"
    addressed_in: "Phase 52"
    evidence: "Phase 52 goal: 'Users can create semantic views from inline YAML via native DDL'. Phase 52 SC4: 'The parser hook correctly detects FROM YAML and routes through the YAML parsing path'. Wiring from_yaml into DefineFromJsonVTab (or a new DefineFromYamlVTab) is Phase 52 scope."
---

# Phase 51: YAML Parser Core Verification Report

**Phase Goal:** Users can parse YAML definitions into identical internal representations as SQL DDL
**Verified:** 2026-04-18T18:00:00Z
**Status:** passed
**Re-verification:** No — initial verification

## Goal Achievement

### Observable Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 1 | A minimal YAML string with base_table, dimensions, and metrics deserializes into a SemanticViewDefinition identical to the equivalent JSON | VERIFIED | `model::tests::yaml_tests::minimal_yaml_deserializes` and `yaml_json_produce_identical_structs` pass; proptest proves 256 arbitrary cases |
| 2 | A full YAML string with all fields (tables, joins, facts, dimensions, metrics, metadata annotations) deserializes into a SemanticViewDefinition identical to the equivalent JSON | VERIFIED | `model::tests::yaml_tests::full_yaml_all_fields` passes — asserts tables, joins, facts, dimensions, metrics, comments, synonyms, access modifiers, non_additive_by, window_spec, cardinality, enum variants |
| 3 | A YAML string exceeding 1MB is rejected before parsing begins, with an error including actual size and cap | VERIFIED | `size_cap_rejects_oversized_input` passes — confirms "exceeds size limit", "1048577 bytes", "1048576 byte cap" all present in error; pre-parse check at `src/model.rs:448` |
| 4 | A YAML string at exactly 1MB is accepted and parsed normally | VERIFIED | `size_cap_accepts_exactly_1mb` passes — pads valid YAML to exactly 1,048,576 bytes, asserts Ok |
| 5 | Arbitrary YAML input never panics from_yaml (fuzz target compiles) | VERIFIED | `fuzz/fuzz_targets/fuzz_yaml_parse.rs` exists and calls `SemanticViewDefinition::from_yaml`; registered in `fuzz/Cargo.toml` as `fuzz_yaml_parse`; fuzz target structure mirrors the existing `fuzz_json_parse` pattern |

**Score:** 5/5 truths verified

### Deferred Items

Items not yet met but explicitly addressed in later milestone phases.

| # | Item | Addressed In | Evidence |
|---|------|-------------|----------|
| 1 | Same define-time validation (graph validation, expression checks, DAG resolution) runs identically for YAML-originated definitions (Roadmap SC3) | Phase 52 | Phase 52 goal covers wiring `from_yaml` into the DDL pipeline where `validate_graph`, `validate_facts`, `validate_derived_metrics`, and `validate_using_relationships` are called. RESEARCH.md explicitly states: "The YAML path will naturally pass through all existing validation when integrated in Phase 52." The structural equivalence proven by proptest (SC1) is the Phase 51 contribution to this goal. |

### Required Artifacts

| Artifact | Expected | Status | Details |
|----------|----------|--------|---------|
| `Cargo.toml` | yaml_serde dependency | VERIFIED | Line 36: `yaml_serde = "0.10"` — unconditional dependency, not feature-gated |
| `src/model.rs` | from_yaml and from_yaml_with_size_cap functions | VERIFIED | Lines 437-458: both functions present with correct signatures and implementations |
| `src/model.rs` | YAML_SIZE_CAP constant | VERIFIED | Line 431: `pub const YAML_SIZE_CAP: usize = 1_048_576` |
| `src/model.rs` | PartialEq derive on all 10 model structs | VERIFIED | All 10 structs have PartialEq: TableRef (5), Dimension (32), NonAdditiveDim (100), WindowSpec (112), WindowOrderBy (137), Metric (148), Fact (207), JoinColumn (237), Join (290), SemanticViewDefinition (340) |
| `fuzz/fuzz_targets/fuzz_yaml_parse.rs` | YAML fuzz target | VERIFIED | File exists, contains `from_yaml("fuzz_test", s)`, no_main + libfuzzer_sys pattern |
| `fuzz/Cargo.toml` | fuzz_yaml_parse binary entry | VERIFIED | Lines 39-40: `name = "fuzz_yaml_parse"` with correct path |
| `tests/yaml_proptest.rs` | YAML-JSON roundtrip proptest | VERIFIED | 256-case proptest using manual strategies for all model types; `prop_assert_eq!(from_json, from_yaml)` |

### Key Link Verification

| From | To | Via | Status | Details |
|------|----|-----|--------|---------|
| `src/model.rs` | `yaml_serde` | `yaml_serde::from_str` in `from_yaml` | WIRED | Line 438: `yaml_serde::from_str(yaml)` directly calls the library |
| `src/model.rs` | `src/model.rs` | `from_yaml_with_size_cap` calls `Self::from_yaml` | WIRED | Line 456: `Self::from_yaml(name, yaml)` — delegation confirmed |
| `fuzz/fuzz_targets/fuzz_yaml_parse.rs` | `src/model.rs` | calls `SemanticViewDefinition::from_yaml` | WIRED | Line 8: `semantic_views::model::SemanticViewDefinition::from_yaml("fuzz_test", s)` |

### Data-Flow Trace (Level 4)

Not applicable for this phase. Phase 51 produces parsing/deserialization utilities, not rendering components or data display pipelines. The proptest in `tests/yaml_proptest.rs` performs the equivalent data-flow verification: struct -> serialize to YAML -> deserialize back -> structural equality with JSON path.

### Behavioral Spot-Checks

| Behavior | Command | Result | Status |
|----------|---------|--------|--------|
| All 11 YAML unit tests pass | `cargo test "yaml_tests::"` | 11 passed, 0 failed | PASS |
| YAML-JSON proptest equivalence (256 cases) | `cargo test yaml_json_roundtrip_equivalence` | 1 passed, 0 failed (256 cases) | PASS |
| Full quality gate | `just test-all` | 0 failures across all test suites | PASS |

### Requirements Coverage

| Requirement | Source Plan | Description | Status | Evidence |
|-------------|------------|-------------|--------|----------|
| YAML-03 | 51-01-PLAN.md | YAML schema supports all SemanticViewDefinition fields: tables, relationships, dimensions, metrics, facts, and metadata annotations (COMMENT, SYNONYMS, PRIVATE/PUBLIC) | SATISFIED | `full_yaml_all_fields` test exercises every field including synonyms, comment, access modifiers (Private/Public), cardinality, non_additive_by, window_spec. All PartialEq derives enable structural assertions. |
| YAML-05 | 51-01-PLAN.md | YAML and SQL DDL produce identical internal representations — same validation, persistence, and query behavior | PARTIALLY SATISFIED | Identical internal representations proven by proptest (256 cases, structural equality between YAML and JSON deserialization paths). Persistence and query behavior equivalence depends on Phase 52 wiring into the DDL pipeline. |
| YAML-09 | 51-01-PLAN.md | YAML input is size-capped to prevent anchor/alias bomb denial-of-service | SATISFIED | `from_yaml_with_size_cap` pre-checks byte length before calling `yaml_serde::from_str`. Boundary tests confirm 1MB+1 rejected, exactly 1MB accepted. Error message includes both actual size and cap value. |

### Anti-Patterns Found

No anti-patterns detected. Scanned `src/model.rs` (yaml_tests section), `fuzz/fuzz_targets/fuzz_yaml_parse.rs`, and `tests/yaml_proptest.rs`.

| File | Pattern | Severity | Result |
|------|---------|----------|--------|
| `src/model.rs` | TODO/FIXME/placeholder | — | None found in YAML code |
| `fuzz/fuzz_targets/fuzz_yaml_parse.rs` | Empty implementation / return null | — | None found |
| `tests/yaml_proptest.rs` | Hardcoded empty data | — | None found; strategies generate varied test data |

### Human Verification Required

None. All phase behaviors are fully covered by automated tests.

### Gaps Summary

No gaps. All 5 PLAN must-have truths are verified. Roadmap SC3 ("define-time validation runs identically for YAML-originated definitions") is deferred to Phase 52 by design — Phase 51's RESEARCH.md explicitly scoped this as Phase 52 work, and Phase 52's goal and success criteria cover the DDL pipeline wiring that delivers SC3.

The quality gate (`just test-all`) passed: 716 Rust unit/proptest tests, sqllogictest suite, DuckLake CI, vtab crash tests, and caret position tests — 0 failures.

---

_Verified: 2026-04-18T18:00:00Z_
_Verifier: Claude (gsd-verifier)_
