wx-cli/.gsd/milestones/M001/slices/S01/tasks/T01-PLAN.md

estimated_steps	estimated_files	skills_used
16	2

T01: Create transport module with traits, generic handler, and TCP implementation

Why: Establish the transport abstraction layer — the core deliverable of S01. Define traits that abstract over Unix socket, Windows named pipe, and TCP. Extract the duplicated JSON-line protocol handling from server.rs into a generic handle_connection function.

Steps:

1. Create src/transport/mod.rs with module declarations
2. Define TransportAddr enum with variants: Unix(PathBuf), WindowsPipe(String), Tcp(SocketAddr)
3. Define Listener trait (object-safe): type Stream (Send + AsyncRead + AsyncWrite + Unpin), async fn accept(&mut self) -> Result<Self::Stream>
4. Define Connector trait (object-safe): same Stream type, async fn connect(&self, addr: &TransportAddr) -> Result<Self::Stream>
5. Implement handle_connection<S> as an async generic function accepting S: AsyncRead + AsyncWrite + Unpin, &DbCache, &Arc<tokio::sync::RwLock<Arc<Names>>> — reads one JSON line, parses Request, calls dispatch, writes one JSON-line Response (extracted from current handle_connection_unix/handle_connection_windows in server.rs)
6. Implement struct TcpListener wrapping tokio::net::TcpListener with Listener impl
7. Implement struct TcpConnector with Connector impl using tokio::net::TcpStream
8. Add pub mod transport; to src/main.rs
9. Keep existing server.rs/handler functions untouched at this point (moved in T02)

Constraints:

• Listener and Connector must be object-safe (no Self in method params/returns beyond standard patterns)
• handle_connection must be pub(crate) for server.rs to use
• Do NOT modify ipc.rs (protocol types are already well-abstracted)
• TcpListener/TcpConnector use std tokio::net — already available as dependency

Inputs

• src/ipc.rs
• src/daemon/server.rs
• src/daemon/cache.rs
• src/daemon/query.rs
• Cargo.toml

Expected Output

• src/transport/mod.rs

Verification

cargo check && test -f src/transport/mod.rs && grep -q "pub trait Listener" src/transport/mod.rs && grep -q "pub trait Connector" src/transport/mod.rs && grep -q "pub async fn handle_connection" src/transport/mod.rs && grep -q "pub struct TcpListener" src/transport/mod.rs && grep -q "pub struct TcpConnector" src/transport/mod.rs