feat: share one npm install across work directories

README.md

@@ -239,7 +239,8 @@ config = PGliteConfig(
     timeout=60,                    # Extended timeout for CI/CD
     log_level="INFO",              # Balanced logging
     cleanup_on_exit=True,          # Automatic cleanup
-    work_dir=Path("./test-data")   # Custom directory
+    work_dir=Path("./test-data"),  # Custom directory
+    node_modules_dir=Path("/tmp/py-pglite-npm")  # One npm install shared by all workers
 )
 
 with SQLAlchemyPGliteManager(config) as manager:

src/py_pglite/config.py

@@ -35,6 +35,11 @@ class PGliteConfig:
         work_dir: Working directory for PGlite files (default: None, uses temp)
         node_modules_check: Whether to verify node_modules exists (default: True)
         auto_install_deps: Whether to auto-install npm dependencies (default: True)
+        node_modules_dir: Directory to install npm dependencies into once and
+            share across work directories (for example across pytest-xdist
+            workers).  When set, npm installs run in this directory, guarded
+            by a file lock, and each work directory gets a ``node_modules``
+            link to it.  Default: None (install into each work directory).
         extensions: List of PGlite extensions to enable (e.g., ["pgvector"])
         node_options: Custom NODE_OPTIONS for the Node.js process
         use_tcp: Use TCP socket instead of Unix domain socket (default: False)
@@ -49,6 +54,7 @@ class PGliteConfig:
     work_dir: Path | None = None
     node_modules_check: bool = True
     auto_install_deps: bool = True
+    node_modules_dir: Path | None = None
     extensions: list[str] | None = None
     node_options: str | None = None
     use_tcp: bool = False
@@ -74,6 +80,9 @@ def __post_init__(self) -> None:
         if self.work_dir is not None:
             self.work_dir = Path(self.work_dir).resolve()
 
+        if self.node_modules_dir is not None:
+            self.node_modules_dir = Path(self.node_modules_dir).resolve()
+
         # Validate TCP configuration
         if self.use_tcp:
             if not (1 <= self.tcp_port <= 65535):

src/py_pglite/extensions.py

@@ -5,7 +5,10 @@
 """
 
 SUPPORTED_EXTENSIONS: dict[str, dict[str, str]] = {
-    "pgvector": {"module": "@electric-sql/pglite/vector", "name": "vector"},
+    "pgvector": {
+        "module": "@electric-sql/pglite-pgvector",
+        "name": "vector",
+    },
     "pg_trgm": {"module": "@electric-sql/pglite/contrib/pg_trgm", "name": "pg_trgm"},
     "btree_gin": {
         "module": "@electric-sql/pglite/contrib/btree_gin",