fix: host/port defaults no longer shadow a dsn's embedded host/port (psql-5)

Signed-off-by: disqualifier <dev@disqualifier.me>

README.md

@@ -10,18 +10,18 @@ a sibling of the `mongo` lib. Class is **`PsqlDB`**.
 `requirements.txt`:
 
 ```
-psql @ git+ssh://git@git.rethinkstudios.io/rethink-public/psql.git@v0.1.0
+psql @ git+ssh://git@git.rethinkstudios.io/rethink-public/psql.git@v0.1.4
 ```
 
 Direct:
 
 ```bash
-pip install "psql @ git+ssh://git@git.rethinkstudios.io/rethink-public/psql.git@v0.1.0"
+pip install "psql @ git+ssh://git@git.rethinkstudios.io/rethink-public/psql.git@v0.1.4"
 ```
 
 Pulls `asyncpg`.
 
-Drop the `@v0.1.0` suffix from the line above to install the latest unpinned.
+Drop the `@v0.1.4` suffix from the line above to install the latest unpinned.
 
 ## The two-layer API
 
@@ -63,6 +63,12 @@ async with PsqlDB(database="app", user="postgres") as db:
     await db.insert("events", {"kind": "login"})
 ```
 
+`host`/`port` default to `None`, not `"localhost"`/`5432` — asyncpg only reads a `dsn`'s
+embedded host/port when the `host`/`port` kwargs are falsy, so passing `dsn=...` in
+`pool_kwargs` (with no `host`/`port` of your own) lets the dsn's server reach asyncpg
+instead of being silently overridden. The no-dsn path above still defaults to
+`localhost:5432` when you don't pass `host`.
+
 ### Layer 2 — raw SQL for the complex queries
 
 ```python

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "psql"
-version = "0.1.0"
+version = "0.1.4"
 description = "async postgres wrapper over asyncpg: two-layer API (friendly verbs + raw escape hatch), fail-loud, config-free"
 requires-python = ">=3.10"
 dependencies = [

src/psql/psql.py

@@ -18,6 +18,13 @@ lifecycle:
     validates it with `SELECT 1` so a bad host/credentials fails loud immediately rather
     than on the first real op, and returns self. close() closes the pool.
 
+dsn:
+    host/port default to None, not "localhost"/5432 — asyncpg only reads a dsn's
+    embedded host/port when the host/port kwargs are falsy, so a hardcoded default would
+    silently shadow the dsn's server. pass dsn=... in pool_kwargs alone (no host/port) to
+    let the dsn's own host/port reach asyncpg; the no-dsn path still defaults to
+    localhost:5432.
+
 two-layer API:
     LAYER 1 — friendly, portable verbs for simple single-table CRUD. these hide the
     dialect and are byte-for-byte identical to the `mysql` lib, so a dev swaps psql<->mysql
@@ -75,8 +82,8 @@ class PsqlDB:
 
     def __init__(
         self,
-        host: str = "localhost",
-        port: int = 5432,
+        host: Optional[str] = None,
+        port: Optional[int] = None,
         database: Optional[str] = None,
         user: Optional[str] = None,
         password: Optional[str] = None,
@@ -91,7 +98,19 @@ class PsqlDB:
         host/port/database/user/password/min_size/max_size/command_timeout are injected by
         the caller. extra pool_kwargs pass through to asyncpg.create_pool (ssl, server_
         settings, dsn, etc). `host` may be a unix socket directory as well as a hostname.
+
+        host/port default to None here (not "localhost"/5432) because asyncpg only reads
+        a dsn's embedded host/port when the host/port kwargs are falsy — a hardcoded
+        default would silently shadow the dsn's server and connect you to the wrong one.
+        when no dsn is passed, host/port fall back to localhost:5432 (the common no-dsn
+        path is unchanged); when a dsn is passed, host/port stay None unless the caller
+        explicitly overrides them, letting the dsn's own host/port reach asyncpg.
         """
+        if "dsn" not in pool_kwargs:
+            if host is None:
+                host = "localhost"
+            if port is None:
+                port = 5432
         self._config = dict(
             host=host,
             port=port,
@@ -108,14 +127,24 @@ class PsqlDB:
     async def connect(self) -> "PsqlDB":
         """build the pool and validate it with SELECT 1; fail loud on bad config
 
-        returns self so callers can write `db = await PsqlDB(...).connect()`.
+        returns self so callers can write `db = await PsqlDB(...).connect()`. if called
+        again on an already-connected instance the previous pool is closed first (no
+        orphaned pool); if the SELECT-1 validation fails the freshly-built pool is torn
+        down before re-raising, so a failed connect() never leaks a live pool.
         """
+        if self._pool is not None:
+            await self.close()
+        pool = await asyncpg.create_pool(**self._config)
         try:
-            self._pool = await asyncpg.create_pool(**self._config)
-            await self._pool.fetchval("SELECT 1")
+            await pool.fetchval("SELECT 1")
         except _DRIVER_ERRORS:
-            log.exception("psql.connect() failed")
+            log.exception("psql.connect() validation failed")
+            await pool.close()
             raise
+        except BaseException:
+            await pool.close()
+            raise
+        self._pool = pool
         return self
 
     async def close(self) -> None:
@@ -338,8 +367,16 @@ class _Transaction:
 
     async def __aenter__(self):
         self._conn = await self._pool.acquire()
+        try:
             self._tx = self._conn.transaction()
             await self._tx.start()
+        except BaseException:
+            # start() (or transaction()) failing after acquire would otherwise leak the
+            # pooled connection — __aexit__ is not called when __aenter__ raises. release
+            # it and reset so a failed transaction start never burns a pool slot.
+            await self._pool.release(self._conn)
+            self._conn = None
+            raise
         return self._conn
 
     async def __aexit__(self, exc_type, exc, tb) -> None:
@@ -355,13 +392,21 @@ class _Transaction:
 def _where(conditions: Optional[Dict[str, Any]]) -> tuple:
     """build a parameterized `WHERE col = $1 AND ...` clause + the params list
 
-    returns ("", []) when there are no conditions. equality only.
+    returns ("", []) when there are no conditions. equality only. a None value renders as
+    `col IS NULL` (not `col = $n` bound to NULL, which sql never matches) and does not
+    consume a placeholder.
     """
     if not conditions:
         return "", []
-    cols = list(conditions.keys())
-    clause = " AND ".join(f"{_quote_ident(c)} = ${i + 1}" for i, c in enumerate(cols))
-    return f" WHERE {clause}", list(conditions.values())
+    parts = []
+    params = []
+    for col, val in conditions.items():
+        if val is None:
+            parts.append(f"{_quote_ident(col)} IS NULL")
+        else:
+            params.append(val)
+            parts.append(f"{_quote_ident(col)} = ${len(params)}")
+    return f" WHERE {' AND '.join(parts)}", params
 
 
 def _status_count(status: str) -> int: