new approach

Author: sungchun12

sqlmesh/core/linter/rules/builtin.py

@@ -7,7 +7,6 @@
 from sqlglot.expressions import Star
 from sqlglot.helper import subclasses
 
-from sqlmesh.core.node import IntervalUnit
 from sqlmesh.core.constants import EXTERNAL_MODELS_YAML
 from sqlmesh.core.dialect import normalize_model_name
 from sqlmesh.core.linter.helpers import (
@@ -279,9 +278,7 @@ class CronIntervalAlignment(Rule):
     """Upstream model has a cron expression with longer intervals than downstream model."""
 
     def check_model(self, model: Model) -> t.Optional[t.List[RuleViolation]]:
-        placeholder_start_date = "2020-01-01 10:00:00"
-
-        this_model_cron_next = model.cron_next(placeholder_start_date)
+        placeholder_start_date = "2020-01-01 00:25:00"
 
         violations = []
         for upstream_model_name in model.depends_on:
@@ -296,22 +293,23 @@ def check_model(self, model: Model) -> t.Optional[t.List[RuleViolation]]:
             if upstream_model.kind.name in skip_kinds:
                 continue
 
-            upstream_model_cron_next = upstream_model.cron_next(placeholder_start_date)
-
-            upstream_cron_interval_unit = IntervalUnit.from_cron(upstream_model.cron)
-            this_cron_interval_unit = IntervalUnit.from_cron(model.cron)
-            rule_violation = RuleViolation(
-                rule=self,
-                violation_msg=f"Upstream model {upstream_model_name} has longer cron interval ({upstream_model.cron}) "
-                f"than this model ({model.cron})",
-            )
+            for _ in range(12):
+                this_next = model.cron_next(placeholder_start_date)
+                upstream_next = upstream_model.cron_next(placeholder_start_date)
+                current_time = this_next
+
+                # Find the first iteration pair where upstream runs after downstream
+                if upstream_next > this_next:
+                    violations.append(
+                        RuleViolation(
+                            rule=self,
+                            violation_msg=f"Upstream model {upstream_model_name} runs less frequently ({upstream_model.cron}) than this model ({model.cron})",
+                        )
+                    )
+                    break  # Found violation, stop checking this upstream model
+                else:
+                    return None
 
-            if upstream_model_cron_next > this_model_cron_next:
-                violations.append(rule_violation)
-            elif upstream_cron_interval_unit.seconds > this_cron_interval_unit.seconds:
-                violations.append(rule_violation)
-            elif upstream_model_cron_next <= this_model_cron_next:
-                return None
         return violations
 
 

tests/core/linter/test_builtin.py

@@ -187,14 +187,19 @@ def test_no_missing_external_models_with_existing_file_not_ending_in_newline(
             "@weekly",
             "@daily",
             1,
-            'Upstream model "memory"."sushi"."step_1" has longer cron interval (@weekly) than this model (@daily)',
+            'Upstream model "memory"."sushi"."step_1" runs less frequently (@weekly) than this model (@daily)',
+        ),
+        (
+            "5 * * * *",
+            "0 * * * *",
+            1,
+            'Upstream model "memory"."sushi"."step_1" runs less frequently (5 * * * *) than this model (0 * * * *)',
         ),
-        ("5 * * * *", "0 * * * *", 0, None),
         (
             "15 10 * * *",
             "0 * * * *",
             1,
-            'Upstream model "memory"."sushi"."step_1" has longer cron interval (15 10 * * *) than this model (0 * * * *)',
+            'Upstream model "memory"."sushi"."step_1" runs less frequently (15 10 * * *) than this model (0 * * * *)',
         ),
     ],
 )
@@ -265,8 +270,8 @@ def test_cron_interval_alignment(
             "@daily",
             2,
             [
-                'Upstream model "memory"."sushi"."step_a" has longer cron interval (@weekly) than this model (@daily)',
-                'Upstream model "memory"."sushi"."step_b" has longer cron interval (@weekly) than this model (@daily)',
+                'Upstream model "memory"."sushi"."step_a" runs less frequently (@weekly) than this model (@daily)',
+                'Upstream model "memory"."sushi"."step_b" runs less frequently (@weekly) than this model (@daily)',
             ],
         ),
     ],