Database as a context manager, fixed many pytest warnings

* Database can now work as a context manager
* Claude Code helped fix a ton of .close() warnings

https://gistpreview.github.io/?730f0c5dc38528a1dd0615f330bd5481

* New autouse fixture to help with test warnings

Refs https://github.com/simonw/sqlite-utils/issues/692#issuecomment-3644371889

* Fix all remaining resource warnings

https://gistpreview.github.io/?0bb8e869b82f6ff0db647de755182502

Closes #692

tests/conftest.py

@@ -14,6 +14,26 @@ def pytest_configure(config):
     sys._called_from_test = True
 
 
+@pytest.fixture(autouse=True)
+def close_all_databases():
+    """Automatically close all Database objects created during a test."""
+    databases = []
+    original_init = Database.__init__
+
+    def tracking_init(self, *args, **kwargs):
+        original_init(self, *args, **kwargs)
+        databases.append(self)
+
+    Database.__init__ = tracking_init
+    yield
+    Database.__init__ = original_init
+    for db in databases:
+        try:
+            db.close()
+        except Exception:
+            pass
+
+
 @pytest.fixture
 def fresh_db():
     return Database(memory=True)
@@ -38,4 +58,5 @@ def db_path(tmpdir):
     path = str(tmpdir / "test.db")
     db = sqlite3.connect(path)
     db.executescript(CREATE_TABLES)
+    db.close()
     return path

tests/test_analyze_tables.py

@@ -137,6 +137,7 @@ def db_to_analyze_path(db_to_analyze, tmpdir):
     db = sqlite3.connect(path)
     sql = "\n".join(db_to_analyze.iterdump())
     db.executescript(sql)
+    db.close()
     return path
 
 

tests/test_cli.py

@@ -19,9 +19,11 @@ def _supports_pragma_function_list():
     db = Database(memory=True)
     try:
         db.execute("select * from pragma_function_list()")
+        return True
     except Exception:
         return False
-    return True
+    finally:
+        db.close()
 
 
 def _has_compiled_ext():

tests/test_cli_memory.py

@@ -328,7 +328,8 @@ def test_memory_return_db(tmpdir):
     from sqlite_utils.cli import cli
 
     path = str(tmpdir / "dogs.csv")
-    open(path, "w").write("id,name\n1,Cleo")
+    with open(path, "w") as f:
+        f.write("id,name\n1,Cleo")
 
     with click.Context(cli) as ctx:
         db = ctx.invoke(cli.commands["memory"], paths=(path,), return_db=True)

tests/test_introspect.py

@@ -2,6 +2,14 @@ from sqlite_utils.db import Index, View, Database, XIndex, XIndexColumn
 import pytest
 
 
+def _check_supports_strict():
+    """Check if SQLite supports strict tables without leaking the database."""
+    db = Database(memory=True)
+    result = db.supports_strict
+    db.close()
+    return result
+
+
 def test_table_names(existing_db):
     assert ["foo"] == existing_db.table_names()
 
@@ -282,7 +290,7 @@ def test_use_rowid(fresh_db):
 
 
 @pytest.mark.skipif(
-    not Database(memory=True).supports_strict,
+    not _check_supports_strict(),
     reason="Needs SQLite version that supports strict",
 )
 @pytest.mark.parametrize(

tests/test_plugins.py

@@ -9,9 +9,11 @@ def _supports_pragma_function_list():
     db = Database(memory=True)
     try:
         db.execute("select * from pragma_function_list()")
+        return True
     except Exception:
         return False
-    return True
+    finally:
+        db.close()
 
 
 def test_register_commands():

tests/test_recreate.py

@@ -14,8 +14,11 @@ def test_recreate_ignored_for_in_memory():
 
 def test_recreate_not_allowed_for_connection():
     conn = sqlite3.connect(":memory:")
-    with pytest.raises(AssertionError):
-        Database(conn, recreate=True)
+    try:
+        with pytest.raises(AssertionError):
+            Database(conn, recreate=True)
+    finally:
+        conn.close()
 
 
 @pytest.mark.parametrize(

tests/test_register_function.py

@@ -42,39 +42,46 @@ def test_register_function_deterministic(fresh_db):
 
 
 def test_register_function_deterministic_tries_again_if_exception_raised(fresh_db):
+    # Save the original connection so we can close it later
+    original_conn = fresh_db.conn
     fresh_db.conn = MagicMock()
     fresh_db.conn.create_function = MagicMock()
 
-    @fresh_db.register_function(deterministic=True)
-    def to_lower_2(s):
-        return s.lower()
+    try:
 
-    fresh_db.conn.create_function.assert_called_with(
-        "to_lower_2", 1, to_lower_2, deterministic=True
-    )
+        @fresh_db.register_function(deterministic=True)
+        def to_lower_2(s):
+            return s.lower()
 
-    first = True
+        fresh_db.conn.create_function.assert_called_with(
+            "to_lower_2", 1, to_lower_2, deterministic=True
+        )
 
-    def side_effect(*args, **kwargs):
-        # Raise exception only first time this is called
-        nonlocal first
-        if first:
-            first = False
-            raise sqlite3.NotSupportedError()
+        first = True
 
-    # But if sqlite3.NotSupportedError is raised, it tries again
-    fresh_db.conn.create_function.reset_mock()
-    fresh_db.conn.create_function.side_effect = side_effect
+        def side_effect(*args, **kwargs):
+            # Raise exception only first time this is called
+            nonlocal first
+            if first:
+                first = False
+                raise sqlite3.NotSupportedError()
 
-    @fresh_db.register_function(deterministic=True)
-    def to_lower_3(s):
-        return s.lower()
+        # But if sqlite3.NotSupportedError is raised, it tries again
+        fresh_db.conn.create_function.reset_mock()
+        fresh_db.conn.create_function.side_effect = side_effect
 
-    # Should have been called once with deterministic=True and once without
-    assert fresh_db.conn.create_function.call_args_list == [
-        call("to_lower_3", 1, to_lower_3, deterministic=True),
-        call("to_lower_3", 1, to_lower_3),
-    ]
+        @fresh_db.register_function(deterministic=True)
+        def to_lower_3(s):
+            return s.lower()
+
+        # Should have been called once with deterministic=True and once without
+        assert fresh_db.conn.create_function.call_args_list == [
+            call("to_lower_3", 1, to_lower_3, deterministic=True),
+            call("to_lower_3", 1, to_lower_3),
+        ]
+    finally:
+        # Close the original connection that was replaced with the mock
+        original_conn.close()
 
 
 def test_register_function_replace(fresh_db):