lazy: expand cols in filter (#3128)

polars/polars-lazy/src/logical_plan/builder.rs

@@ -271,7 +271,10 @@ impl LogicalPlanBuilder {
     /// Apply a filter
     pub fn filter(self, predicate: Expr) -> Self {
         let predicate = if has_expr(&predicate, |e| {
-            matches!(e, Expr::Wildcard | Expr::RenameAlias { .. })
+            matches!(
+                e,
+                Expr::Wildcard | Expr::RenameAlias { .. } | Expr::Columns(_)
+            )
         }) {
             let rewritten = rewrite_projections(vec![predicate], self.0.schema(), &[]);
             combine_predicates_expr(rewritten.into_iter())

polars/tests/it/lazy/predicate_queries.rs

@@ -39,3 +39,25 @@ fn filter_true_lit() -> Result<()> {
     assert!(res.frame_equal_missing(&df));
     Ok(())
 }
+
+#[test]
+fn test_combine_columns_in_filter() -> Result<()> {
+    let df = df![
+        "a" => [1, 2, 3],
+        "b" => [None, Some("a"), Some("b")]
+    ]?;
+
+    let out = df
+        .lazy()
+        .filter(cols(vec!["a".to_string(), "b".to_string()]).gt(lit(2)))
+        .collect()?;
+
+    let expected = df![
+        "a" => [3],
+        "b" => ["b"],
+    ]?;
+
+    // "b" > "2" == true
+    assert!(out.frame_equal(&expected));
+    Ok(())
+}