Split out _iter_complete_sql_statements

To make it clearer why we are avoiding executescript()

sqlite_utils/db.py

@@ -196,6 +196,19 @@ DEFAULT = Default()
 Tracer = Callable[[str, Optional[Union[Sequence[Any], Dict[str, Any]]]], None]
 
 
+def _iter_complete_sql_statements(sql: str) -> Generator[str, None, None]:
+    statement = []
+    for char in sql:
+        statement.append(char)
+        statement_sql = "".join(statement).strip()
+        if statement_sql and sqlite3.complete_statement(statement_sql):
+            yield statement_sql
+            statement = []
+    statement_sql = "".join(statement).strip()
+    if statement_sql:
+        yield statement_sql
+
+
 COLUMN_TYPE_MAPPING: Dict[Any, str] = {
     float: "REAL",
     int: "INTEGER",
@@ -618,16 +631,9 @@ class Database:
     def _executescript(self, sql: str) -> sqlite3.Cursor:
         if self.conn.in_transaction:
             cursor = self.conn.cursor()
-            statement = []
+            # avoid sqlite3.executescript()'s implicit commit:
-            for char in sql:
+            for statement in _iter_complete_sql_statements(sql):
-                statement.append(char)
+                cursor.execute(statement)
-                statement_sql = "".join(statement).strip()
-                if statement_sql and sqlite3.complete_statement(statement_sql):
-                    cursor.execute(statement_sql)
-                    statement = []
-            statement_sql = "".join(statement).strip()
-            if statement_sql:
-                cursor.execute(statement_sql)
             return cursor
         return self.conn.executescript(sql)
 

tests/test_atomic.py

@@ -1,8 +1,46 @@
 import pytest
 
+from sqlite_utils.db import _iter_complete_sql_statements
 from sqlite_utils.utils import sqlite3
 
 
+@pytest.mark.parametrize(
+    "sql,expected",
+    (
+        (
+            "CREATE TABLE t(id); INSERT INTO t VALUES (1)",
+            ["CREATE TABLE t(id);", "INSERT INTO t VALUES (1)"],
+        ),
+        (
+            "INSERT INTO t VALUES ('a;b');",
+            ["INSERT INTO t VALUES ('a;b');"],
+        ),
+        (
+            "-- comment;\nCREATE TABLE t(id);",
+            ["-- comment;\nCREATE TABLE t(id);"],
+        ),
+        (
+            """
+            CREATE TRIGGER t_ai AFTER INSERT ON t
+            BEGIN
+                UPDATE t SET value = 'a;b' WHERE id = new.id;
+                INSERT INTO log VALUES ('x;y');
+            END;
+            """,
+            [
+                "CREATE TRIGGER t_ai AFTER INSERT ON t\n"
+                "            BEGIN\n"
+                "                UPDATE t SET value = 'a;b' WHERE id = new.id;\n"
+                "                INSERT INTO log VALUES ('x;y');\n"
+                "            END;"
+            ],
+        ),
+    ),
+)
+def test_iter_complete_sql_statements(sql, expected):
+    assert list(_iter_complete_sql_statements(sql)) == expected
+
+
 def test_atomic_commits(fresh_db):
     with fresh_db.atomic():
         fresh_db["dogs"].insert({"id": 1, "name": "Cleo"}, pk="id")
@@ -54,9 +92,10 @@ def test_executescript_does_not_commit_open_atomic_block(fresh_db):
                 CREATE TABLE dogs(id INTEGER PRIMARY KEY, name TEXT);
                 CREATE TRIGGER dogs_ai AFTER INSERT ON dogs
                 BEGIN
-                    UPDATE dogs SET name = upper(new.name) WHERE id = new.id;
+                    UPDATE dogs SET name = upper(new.name) || '; updated' WHERE id = new.id;
                 END;
-                INSERT INTO dogs VALUES (1, 'Cleo');
+                -- This comment has a semicolon;
+                INSERT INTO dogs VALUES (1, 'Cleo; the first');
             """)
             raise RuntimeError("boom")