Fix(macros): ensure @filter condition is evaluated (#1020)

Author: georgesittas

sqlmesh/core/macros.py

@@ -410,11 +410,11 @@ def filter_(evaluator: MacroEvaluator, *args: t.Any) -> t.List[t.Any]:
         >>> from sqlmesh.core.macros import MacroEvaluator
         >>> sql = "@REDUCE(@FILTER([1, 2, 3], x -> x > 1), (x, y) -> x + y)"
         >>> MacroEvaluator().transform(parse_one(sql)).sql()
-        '1 + 2 + 3'
+        '2 + 3'
 
         >>> sql = "@EVAL(@REDUCE(@FILTER([1, 2, 3], x -> x > 1), (x, y) -> x + y))"
         >>> MacroEvaluator().transform(parse_one(sql)).sql()
-        '6'
+        '5'
 
     Args:
         evaluator: MacroEvaluator that invoked the macro
@@ -425,7 +425,7 @@ def filter_(evaluator: MacroEvaluator, *args: t.Any) -> t.List[t.Any]:
     """
     *items, func = args
     items, func = _norm_var_arg_lambda(evaluator, func, *items)  # type: ignore
-    return list(filter(func, items))
+    return list(filter(lambda arg: evaluator.eval_expression(func(arg)), items))
 
 
 @macro("WITH")

tests/core/test_macros.py

@@ -95,6 +95,11 @@ def test_ast_correctness(macro_evaluator):
             {},
         ),
         ("""@SQL(@REDUCE([100, 200, 300, 400], (x,y) -> x + y))""", "1000", {}),
+        (
+            """@SQL(@REDUCE(@FILTER([100, 200, 300, 400], x -> x > 250), (x,y) -> x + y))""",
+            "700",
+            {},
+        ),
         (
             """select @EACH([a, b, c], x -> x and @SQL('@y'))""",
             "SELECT a AND z, b AND z, c AND z",