Crate cratefield_adapter_postgres 

cratefield-adapter-postgres: the Database port over sqlx Postgres for the native runtime (ADR 0004, issue #18). Native only — it must never enter a wasm build.

Native-only gate

The sqlx driver does not compile to wasm, so this crate is impossible to build for a wasm target: src/lib.rs fails compilation with a clear message on wasm32/wasm64, and the sqlx dependency itself is target-gated to non-wasm builds in Cargo.toml. The wasm graph of examples/venture must stay free of this crate (CI asserts it with cargo tree --target wasm32-unknown-unknown -p venture | grep -c sqlx → 0).

Statement pipeline

Modules build queries with sea-query; the port’s Statement carries them rendered with SqliteQueryBuilder (the portable ?-placeholder wire form D1 and rusqlite execute directly). This adapter rewrites ? to Postgres $n placeholders — skipping string literals, quoted identifiers and comments — and binds the sea-query values positionally (src/convert.rs). The migration runner’s own bookkeeping statements are rendered by sea-query’s PostgresQueryBuilder directly.

The SQLite → Postgres mapping actually used

The portable subset (ADR 0004, architecture section 7) is deliberately the intersection of SQLite and Postgres, so migration files run verbatim on both engines:

Portable concept	SQLite	Postgres	Notes
ULID ids	TEXT PRIMARY KEY	TEXT PRIMARY KEY	no AUTOINCREMENT/SERIAL anywhere
timestamps	ISO-8601 TEXT	ISO-8601 TEXT	computed in Rust, never NOW()/datetime()
counters	INTEGER	INTEGER (int4)	referrals, position
booleans	INTEGER 0/1 by convention	INTEGER 0/1 by convention	no SQL BOOLEAN columns; SeaValue::Bool binds as SMALLINT 0/1, and rows read back through Row::get::<bool> accept both
upserts	INSERT … ON CONFLICT …	identical syntax	rendered by sea-query for both dialects
read-back writes	INSERT … RETURNING …	identical syntax	rendered by sea-query for both dialects

batch runs all statements in one transaction (atomic, ADR 0004).

use cratefield_adapter_postgres::Postgres;

let db = Postgres::connect("postgres://user:pass@host:5432/venture").await?;
// db.apply_harness_migrations(&harness).await?;   // library entry point
// … or through Arc<dyn Database> as with any adapter

Modules

testing

Shared Postgres test infrastructure: per-test throwaway databases on the server named by FZ_TEST_POSTGRES_URL, so tests never see each other’s tables (issue #18).

Structs

Postgres

An open Postgres connection pool (sqlx 0.8, runtime-tokio, tls-rustls).

Functions

select_set

Selects the migration set a module contributes to a Postgres deployment: its postgres set when it ships one, else its sqlite set — but only when every file passes the portable-SQL lint (cratefield_core::lint_portable_sql, the same predicate fz doctor enforces, so the two can never drift).