Remove on from cross join tests

py-polars/tests/unit/dataframe/test_df.py

@@ -2145,7 +2145,7 @@ def test_join_suffixes() -> None:
     join_strategies: list[JoinStrategy] = ["left", "inner", "full", "cross"]
     for how in join_strategies:
         # no need for an assert, we error if wrong
-        df_a.join(df_b, on="A", suffix="_y", how=how)["B_y"]
+        df_a.join(df_b, on="A" if how != "cross" else None, suffix="_y", how=how)["B_y"]
 
     df_a.join_asof(df_b, on=pl.col("A").set_sorted(), suffix="_y")["B_y"]
 

py-polars/tests/unit/operations/test_cross_join.py

@@ -25,7 +25,7 @@ def test_cross_join_predicate_pushdown_block_16956() -> None:
     ).cast(pl.Datetime("ms", "Europe/Amsterdam"))
 
     assert (
-        lf.join(lf, on="start_datetime", how="cross")
+        lf.join(lf, how="cross")
         .filter(
             pl.col.end_datetime_right.is_between(
                 pl.col.start_datetime, pl.col.start_datetime.dt.offset_by("132h")

py-polars/tests/unit/streaming/test_streaming_join.py

@@ -103,26 +103,14 @@ def test_streaming_joins() -> None:
 
 
 def test_streaming_cross_join_empty() -> None:
-    df1 = pl.LazyFrame(
-        data={
-            "col1": ["a"],
-        }
-    )
+    df1 = pl.LazyFrame(data={"col1": ["a"]})
 
     df2 = pl.LazyFrame(
-        data={
-            "col1": [],
-        },
-        schema={
-            "col1": str,
-        },
+        data={"col1": []},
+        schema={"col1": str},
     )
 
-    out = df1.join(
-        df2,
-        how="cross",
-        on="col1",
-    ).collect(streaming=True)
+    out = df1.join(df2, how="cross").collect(streaming=True)
     assert out.shape == (0, 2)
     assert out.columns == ["col1", "col1_right"]