From 7df572f2717d71f4f879b8158f4dd096c7860476 Mon Sep 17 00:00:00 2001
From: Nick Crews <nicholas.b.crews@gmail.com>
Date: Sat, 29 Jun 2024 13:11:34 -0800
Subject: [PATCH] test: add some basic cast tests

---
 ibis/backends/tests/test_generic.py | 69 +++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/ibis/backends/tests/test_generic.py b/ibis/backends/tests/test_generic.py
index 3ed4a9db8cc5..8ce1c65fddcc 100644
--- a/ibis/backends/tests/test_generic.py
+++ b/ibis/backends/tests/test_generic.py
@@ -28,6 +28,7 @@
     OracleDatabaseError,
     PolarsSchemaError,
     PsycoPg2InternalError,
+    PsycoPg2SyntaxError,
     Py4JJavaError,
     PyDruidProgrammingError,
     PyODBCDataError,
@@ -1758,6 +1759,74 @@ def hash_256(col):
     backend.assert_series_equal(h1, h2)
 
 
+@pytest.mark.parametrize(
+    ("from_type", "to_type", "from_val", "expected"),
+    [
+        param("int", "float", 0, 0.0),
+        param("float", "int", 0.0, 0),
+        param("string", "int", "0", 0),
+        param("string", "float", "0", 0.0),
+        param(
+            "timestamp",
+            "string",
+            datetime.datetime(2023, 1, 1),
+            "2023-01-01 00:00:00",
+            marks=[
+                pytest.mark.broken(
+                    "datafusion", reason="1672531200000000 (micro-seconds)"
+                ),
+                pytest.mark.broken(["exasol"], reason="2023-01-01 00:00:00.000000"),
+                pytest.mark.broken(["flink"], reason="2023-01-01 00:00:00.000000"),
+                pytest.mark.broken(["impala"], reason="casts to '2023-01-0100:00:00'"),
+                pytest.mark.broken(["mssql"], reason="2023-01-01 00:00:00.000000"),
+                pytest.mark.broken("oracle", reason="01-JAN-23 12.00.00.000000000 AM"),
+                pytest.mark.broken(
+                    "polars", reason="1672531200000000000 (nanoseconds)"
+                ),
+                pytest.mark.broken(["trino"], reason="2023-01-01 00:00:00.000"),
+            ],
+        ),
+        param(
+            "array<int>",
+            "array<string>",
+            [0, 1, 2],
+            ["0", "1", "2"],
+            marks=[
+                pytest.mark.broken(["pandas"], reason="casts to ['0']"),
+                pytest.mark.notimpl(["druid"], raises=PyDruidProgrammingError),
+                pytest.mark.notimpl(["oracle"], raises=OracleDatabaseError),
+                pytest.mark.never(
+                    ["exasol", "impala", "mssql", "mysql", "sqlite"],
+                    reason="backend doesn't support arrays",
+                ),
+            ],
+        ),
+        param(
+            "struct<a: int, b: string>",
+            "struct<a: string, b: int>",
+            {"a": 0, "b": "1"},
+            {"a": "0", "b": 1},
+            marks=[
+                pytest.mark.never(
+                    ["datafusion", "exasol", "impala", "mssql", "mysql", "sqlite"],
+                    reason="backend doesn't support arrays",
+                ),
+                pytest.mark.notimpl(["flink"], raises=Py4JJavaError),
+                pytest.mark.notimpl(["druid"], raises=PyDruidProgrammingError),
+                pytest.mark.notimpl(["oracle"], raises=OracleDatabaseError),
+                pytest.mark.notimpl(["postgres"], raises=PsycoPg2SyntaxError),
+                pytest.mark.notimpl(["risingwave"], raises=PsycoPg2InternalError),
+            ],
+        ),
+    ],
+    ids=str,
+)
+def test_cast(con, from_type, to_type, from_val, expected):
+    expr = ibis.literal(from_val, type=from_type).cast(to_type)
+    result = con.execute(expr)
+    assert result == expected
+
+
 @pytest.mark.notimpl(["pandas", "dask", "oracle", "sqlite"])
 @pytest.mark.parametrize(
     ("from_val", "to_type", "expected"),