From 6b6d6772d580ff56cb36e724cb189349b39d6874 Mon Sep 17 00:00:00 2001
From: George Sittas <giwrgos.sittas@gmail.com>
Date: Mon, 23 Jun 2025 19:40:17 +0300
Subject: [PATCH] Fix: simplify complex expressions when validating boolean
 pydantic fields

---
 sqlmesh/core/model/common.py | 12 ++++++++++--
 tests/core/test_model.py     | 18 +++++++++++++++++-
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/sqlmesh/core/model/common.py b/sqlmesh/core/model/common.py
index 8f2d9e8ff8..1d8ae14442 100644
--- a/sqlmesh/core/model/common.py
+++ b/sqlmesh/core/model/common.py
@@ -336,10 +336,18 @@ def parse_expression(
 
 
 def parse_bool(v: t.Any) -> bool:
-    if isinstance(v, exp.Boolean):
-        return v.this
     if isinstance(v, exp.Expression):
+        if not isinstance(v, exp.Boolean):
+            from sqlglot.optimizer.simplify import simplify
+
+            # Try to reduce expressions like (1 = 1) (see: T-SQL boolean generation)
+            v = simplify(v)
+
+        if isinstance(v, exp.Boolean):
+            return v.this
+
         return str_to_bool(v.name)
+
     return str_to_bool(str(v or ""))
 
 
diff --git a/tests/core/test_model.py b/tests/core/test_model.py
index 01b6606074..7c65f25889 100644
--- a/tests/core/test_model.py
+++ b/tests/core/test_model.py
@@ -10445,7 +10445,7 @@ def test_invalid_sql_model_query() -> None:
             load_sql_based_model(expressions)
 
 
-def test_query_label_and_authorization_macro():
+def test_query_label_and_authorization_macro() -> None:
     @macro()
     def test_query_label_macro(evaluator):
         return "[('key', 'value')]"
@@ -10478,3 +10478,19 @@ def test_authorization_macro(evaluator):
         "query_label": d.parse_one("[('key', 'value')]"),
         "authorization": d.parse_one("'test_authorization'"),
     }
+
+
+def test_boolean_property_validation() -> None:
+    expressions = d.parse(
+        """
+        MODEL (
+           name db.table,
+           enabled @IF(TRUE, TRUE, FALSE),
+           dialect tsql
+        );
+
+        SELECT 1 AS c;
+        """
+    )
+    model = load_sql_based_model(expressions, dialect="tsql")
+    assert model.enabled