feat(bigquery): implement struct literal

Author: krzysztof-kwitt

ibis/backends/bigquery/registry.py

@@ -239,6 +239,12 @@ def _literal(translator, op):
             return "FROM_BASE64('{}')".format(
                 base64.b64encode(value).decode(encoding="utf-8")
             )
+        elif dtype.is_struct():
+            cols = (
+                f'{translator.translate(ops.Literal(op.value[name], dtype=type_))} AS {name}'
+                for name, type_ in zip(dtype.names, dtype.types)
+            )
+            return "STRUCT({})".format(", ".join(cols))
 
     try:
         return literal(translator, op)

ibis/backends/tests/test_struct.py

@@ -51,7 +51,7 @@ def test_all_fields(struct, struct_df):
 _NULL_STRUCT_LITERAL = ibis.NA.cast("struct<a: int64, b: string, c: float64>")
 
 
-@pytest.mark.notimpl(["postgres", "bigquery"])
+@pytest.mark.notimpl(["postgres"])
 @pytest.mark.parametrize("field", ["a", "b", "c"])
 def test_literal(con, field):
     query = _STRUCT_LITERAL[field]