Database(..., execute_plugins=False) mechanism, refs #575

Author: simonw

docs/plugins.rst

@@ -20,6 +20,12 @@ You can see a JSON list of plugins that have been installed by running this:
 
     sqlite-utils plugins
 
+Plugin hooks such as :ref:`plugins_hooks_prepare_connection` affect each instance of the ``Database`` class. You can opt-out of these plugins by creating that class instance like so:
+
+.. code-block:: python
+
+    db = Database(memory=True, execute_plugins=False)
+
 .. _plugins_building:
 
 Building a plugin

sqlite_utils/db.py

@@ -311,6 +311,7 @@ def __init__(
         recursive_triggers: bool = True,
         tracer: Optional[Callable] = None,
         use_counts_table: bool = False,
+        execute_plugins: bool = True,
     ):
         assert (filename_or_conn is not None and (not memory and not memory_name)) or (
             filename_or_conn is None and (memory or memory_name)
@@ -342,8 +343,8 @@ def __init__(
             self.execute("PRAGMA recursive_triggers=on;")
         self._registered_functions: set = set()
         self.use_counts_table = use_counts_table
-
-        pm.hook.prepare_connection(conn=self.conn)
+        if execute_plugins:
+            pm.hook.prepare_connection(conn=self.conn)
 
     def close(self):
         "Close the SQLite connection, and the underlying database file"

tests/test_plugins.py

@@ -49,10 +49,16 @@ def prepare_connection(self, conn):
             conn.create_function("hello", 1, lambda name: f"Hello, {name}!")
 
     db = Database(memory=True)
-    functions = db.execute(
-        "select distinct name from pragma_function_list order by 1"
-    ).fetchall()
-    assert "hello" not in functions
+
+    def _functions(db):
+        return [
+            row[0]
+            for row in db.execute(
+                "select distinct name from pragma_function_list order by 1"
+            ).fetchall()
+        ]
+
+    assert "hello" not in _functions(db)
 
     try:
         plugins.pm.register(HelloFunctionPlugin(), name="HelloFunctionPlugin")
@@ -62,18 +68,14 @@ def prepare_connection(self, conn):
         ]
 
         db = Database(memory=True)
-
-        functions = [
-            row[0]
-            for row in db.execute(
-                "select distinct name from pragma_function_list order by 1"
-            ).fetchall()
-        ]
-        assert "hello" in functions
-
+        assert "hello" in _functions(db)
         result = db.execute('select hello("world")').fetchone()[0]
         assert result == "Hello, world!"
 
+        # Test execute_plugins=False
+        db2 = Database(memory=True, execute_plugins=False)
+        assert "hello" not in _functions(db2)
+
     finally:
         plugins.pm.unregister(name="HelloFunctionPlugin")
         assert plugins.get_plugins() == []