Add SQLite tests for table masked columns (#411)

Adding a new CRYPTBANK sqlite database to the testing suite with metadata for masked columns. Creates relational/sql/e2e tests for this new database with refsols included. The data, during the data generation step, gets "encrypted" via various schemes for most columns which can be reversed (the encryption/decryption schemes are included in the metadata). The e2e tests were written with refsols before the encryption was added, then marked for skipping since they won't be possible to get the right answer until relational handling for masked table columns is added.

Author: knassre-bodo

pydough/unqualified/unqualified_transform.py

@@ -468,7 +468,9 @@ def from_string(
     try:
         tree: ast.AST = ast.parse(source)
     except SyntaxError as e:
-        raise ValueError(f"Syntax error in source PyDough code:\n{str(e)}") from e
+        raise ValueError(
+            f"Syntax error in source PyDough code:\n{source}\n{str(e)}"
+        ) from e
     assert isinstance(tree, ast.AST)
     new_tree: ast.AST = ast.fix_missing_locations(visitor.visit(tree))
     assert isinstance(new_tree, ast.AST)

tests/conftest.py

@@ -485,6 +485,20 @@ def impl(name: str) -> GraphMetadata:
     return impl
 
 
+@pytest.fixture(scope="session")
+def masked_graphs() -> graph_fetcher:
+    """
+    Returns the graphs for the masked databases.
+    """
+
+    @cache
+    def impl(name: str) -> GraphMetadata:
+        path: str = f"{os.path.dirname(__file__)}/test_metadata/masked_graphs.json"
+        return pydough.parse_json_metadata_from_file(file_path=path, graph_name=name)
+
+    return impl
+
+
 @pytest.fixture(scope="session")
 def sqlite_defog_connection() -> DatabaseContext:
     """
@@ -540,6 +554,24 @@ def sqlite_technograph_connection() -> DatabaseContext:
     return DatabaseContext(DatabaseConnection(connection), DatabaseDialect.SQLITE)
 
 
+@pytest.fixture(scope="session")
+def sqlite_cryptbank_connection() -> DatabaseContext:
+    """
+    Returns the SQLITE database connection for the CRYPTBANK database.
+    """
+    # Setup the directory to be the main PyDough directory.
+    base_dir: str = os.path.dirname(os.path.dirname(__file__))
+    # Setup the cryptbank database.
+    subprocess.run(
+        "cd tests; rm -fv gen_data/cryptbank.db; sqlite3 gen_data/cryptbank.db < gen_data/init_cryptbank.sql",
+        shell=True,
+    )
+    path: str = os.path.join(base_dir, "tests/gen_data/cryptbank.db")
+    connection: sqlite3.Connection = sqlite3.connect(":memory:")
+    connection.execute(f"attach database '{path}' as CRBNK")
+    return DatabaseContext(DatabaseConnection(connection), DatabaseDialect.SQLITE)
+
+
 SF_ENVS = ["SF_USERNAME", "SF_PASSWORD", "SF_ACCOUNT"]
 """
     Snowflake environment variables required for connection.