Normalize lambda variables as well

Author: georgesittas

sqlmesh/core/macros.py

@@ -645,7 +645,7 @@ def substitute(
     ) -> exp.Expression | t.List[exp.Expression] | None:
         if isinstance(node, (exp.Identifier, exp.Var)):
             if not isinstance(node.parent, exp.Column):
-                name = node.name
+                name = node.name.lower()
                 if name in args:
                     return args[name].copy()
                 if name in evaluator.locals:
@@ -678,7 +678,7 @@ def substitute(
         return expressions, lambda args: func.this.transform(
             substitute,
             {
-                expression.name: arg
+                expression.name.lower(): arg
                 for expression, arg in zip(
                     func.expressions, args.expressions if isinstance(args, exp.Tuple) else [args]
                 )

tests/core/test_macros.py

@@ -292,6 +292,16 @@ def test_ast_correctness(macro_evaluator):
             "SELECT 'a' + a_z + 'c' + c_a, 'b' + b_z + 'c' + c_b",
             {"y": "c"},
         ),
+        (
+            """select @each(['a'], x -> @X)""",
+            "SELECT 'a'",
+            {},
+        ),
+        (
+            """select @each(['a'], X -> @x)""",
+            "SELECT 'a'",
+            {},
+        ),
         (
             '"is_@{x}"',
             '"is_b"',