From 0ba30890fe6d2f84a89dab2c2f5ceb9d517f2854 Mon Sep 17 00:00:00 2001
From: Anas Khan <83116240+anxkhn@users.noreply.github.com>
Date: Sun, 5 Jul 2026 00:52:21 +0530
Subject: [PATCH] fix(model): raise ConfigError for empty time_column tuple

An empty time_column tuple, e.g. `INCREMENTAL_BY_TIME_RANGE (time_column ())`,
parsed into an empty exp.Tuple and TimeColumn.create indexed v.expressions[0]
without checking, so it surfaced a bare IndexError with no config context
instead of the ConfigError already used for the other empty/invalid
time_column inputs. Guard the empty tuple and raise the same
"Time Column cannot be empty." ConfigError.

Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>
---
 sqlmesh/core/model/kind.py |  2 ++
 tests/core/test_model.py   | 15 +++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/sqlmesh/core/model/kind.py b/sqlmesh/core/model/kind.py
index 7ae1ef8c0d..a8960fc3e1 100644
--- a/sqlmesh/core/model/kind.py
+++ b/sqlmesh/core/model/kind.py
@@ -341,6 +341,8 @@ def to_property(self, dialect: str = "") -> exp.Property:
     @classmethod
     def create(cls, v: t.Any, dialect: str) -> Self:
         if isinstance(v, exp.Tuple):
+            if not v.expressions:
+                raise ConfigError("Time Column cannot be empty.")
             column_expr = v.expressions[0]
             column = (
                 exp.column(column_expr) if isinstance(column_expr, exp.Identifier) else column_expr
diff --git a/tests/core/test_model.py b/tests/core/test_model.py
index 38453691df..6f286e309d 100644
--- a/tests/core/test_model.py
+++ b/tests/core/test_model.py
@@ -2680,6 +2680,21 @@ def test_time_column():
     assert model.time_column.format == "%Y-%m"
     assert model.time_column.expression == d.parse_one("(\"ds\", '%Y-%m')")
 
+    expressions = d.parse(
+        """
+        MODEL (
+            name db.table,
+            kind INCREMENTAL_BY_TIME_RANGE(
+                time_column ()
+            )
+        );
+
+        SELECT col::text, ds::text
+    """
+    )
+    with pytest.raises(ConfigError, match="Time Column cannot be empty."):
+        load_sql_based_model(expressions)
+
 
 def test_default_time_column():
     expressions = d.parse(