rust-worker

name	rust-worker
description	Implements Rust library modules using TDD (test-first) for cairndb-core

Rust Worker

NOTE: Startup and cleanup are handled by worker-base. This skill defines the WORK PROCEDURE.

When to Use This Skill

Use for any feature that implements Rust library code in cairndb-core: new modules, expanding existing modules, adding tests, fixing bugs.

Required Skills

None.

Work Procedure

1. Read context. Read .factory/library/architecture.md and the feature description. Understand what module(s) you're building, their dependencies, and expected behavior.

2. Add dependencies if needed. If the feature requires new crates (serde, serde_json, uuid), add them to cairndb-core/Cargo.toml. Run cargo check to verify they resolve.

3. Create module file(s). Create the .rs file(s) in cairndb-core/src/. Add mod declarations to lib.rs. For public types, add pub use re-exports.

4. Write failing tests first (RED). In the module's #[cfg(test)] mod tests {}, write tests that cover:

   • Happy path for each public function
   • Error cases (invalid input, not-found, etc.)
   • Edge cases from the feature's expectedBehavior

   Run cargo test --package cairndb-core — tests should FAIL (compile errors or assertion failures).

5. Implement to make tests pass (GREEN). Write the minimum implementation to make all tests pass. Follow the architectural patterns in AGENTS.md.

6. Refactor. Clean up code while keeping tests green. Add doc comments to public items.

7. Run full verification:

   • cargo test --workspace — all tests pass (including existing ones)
   • cargo clippy --all-targets — no warnings
   • cargo check --workspace — clean compilation

8. Verify feature's expectedBehavior. Go through each item in the feature's expectedBehavior list and confirm it's covered by a passing test. If any behavior lacks a test, add one.

9. Update lib.rs exports. Ensure cairndb-core/src/lib.rs re-exports all new public types. Ensure cairndb/src/lib.rs re-exports match (it does pub use cairndb_core::*).

Example Handoff

{
   "salientSummary": "Implemented the document module with Document struct (id/system_time/data/get/txn_id accessors) and QueryResult wrapper with IntoIterator. Added serde and serde_json deps. Ran `cargo test --workspace` (12 passing) and `cargo clippy` (clean).",
   "whatWasImplemented": "cairndb-core/src/document.rs: Document struct wrapping id (String), data (serde_json::Map), valid_from (i64), txn_id (i64). Public accessors: id(), system_time() (converts epoch ms to ISO 8601), data(), get(key), txn_id(). Serialize/Deserialize derives. QueryResult struct with len(), is_empty(), documents(), into_documents(), IntoIterator impl. Updated lib.rs with pub mod document and re-exports.",
   "whatWasLeftUndone": "",
   "verification": {
      "commandsRun": [
         {
            "command": "cargo test --workspace",
            "exitCode": 0,
            "observation": "12 tests passed, 0 failed"
         },
         {
            "command": "cargo clippy --all-targets",
            "exitCode": 0,
            "observation": "No warnings"
         }
      ],
      "interactiveChecks": []
   },
   "tests": {
      "added": [
         {
            "file": "cairndb-core/src/document.rs",
            "cases": [
               {
                  "name": "document_id_format",
                  "verifies": "id() returns valid UUIDv7 string"
               },
               {
                  "name": "document_system_time_iso8601",
                  "verifies": "system_time() returns ISO 8601 string"
               },
               {
                  "name": "document_data_access",
                  "verifies": "data() returns user JSON map"
               },
               {
                  "name": "document_get_field",
                  "verifies": "get() returns Some for existing, None for missing"
               },
               {
                  "name": "document_serde_roundtrip",
                  "verifies": "Serialize then Deserialize preserves all fields"
               },
               {
                  "name": "query_result_accessors",
                  "verifies": "len(), is_empty(), documents() work correctly"
               },
               {
                  "name": "query_result_iteration",
                  "verifies": "IntoIterator yields all documents"
               },
               {
                  "name": "query_result_empty",
                  "verifies": "empty result: is_empty()==true, len()==0"
               }
            ]
         }
      ]
   },
   "discoveredIssues": []
}

When to Return to Orchestrator

• Feature depends on a module/type that doesn't exist yet and isn't part of this feature
• Cargo.toml dependency resolution fails
• Existing tests break and the cause is outside this feature's scope
• Architectural ambiguity: the feature description contradicts AGENTS.md or architecture.md