Fix: load dbt model containing only a comment and non-sql jinja (#5368)

Co-authored-by: Jo <46752250+georgesittas@users.noreply.github.com>

Author: treysp

sqlmesh/core/renderer.py

@@ -6,7 +6,7 @@
 from functools import partial
 from pathlib import Path
 
-from sqlglot import exp, parse
+from sqlglot import exp, Dialect
 from sqlglot.errors import SqlglotError
 from sqlglot.helper import ensure_list
 from sqlglot.optimizer.annotate_types import annotate_types
@@ -249,15 +249,24 @@ def _resolve_table(table: str | exp.Table) -> str:
                 ) from ex
 
             if rendered_expression.strip():
-                try:
-                    expressions = [e for e in parse(rendered_expression, read=self._dialect) if e]
-
-                    if not expressions:
-                        raise ConfigError(f"Failed to parse an expression:\n{self._expression}")
-                except Exception as ex:
-                    raise ConfigError(
-                        f"Could not parse the rendered jinja at '{self._path}'.\n{ex}"
-                    ) from ex
+                # ensure there is actual SQL and not just comments and non-SQL jinja
+                dialect = Dialect.get_or_raise(self._dialect)
+                tokens = dialect.tokenize(rendered_expression)
+
+                if tokens:
+                    try:
+                        expressions = [
+                            e for e in dialect.parser().parse(tokens, rendered_expression) if e
+                        ]
+
+                        if not expressions:
+                            raise ConfigError(
+                                f"Failed to parse an expression:\n{rendered_expression}"
+                            )
+                    except Exception as ex:
+                        raise ConfigError(
+                            f"Could not parse the rendered jinja at '{self._path}'.\n{ex}"
+                        ) from ex
 
         if this_model:
             render_kwargs["this_model"] = this_model

tests/dbt/test_model.py

@@ -873,3 +873,24 @@ def test_load_model_dbt_node_name(tmp_path: Path) -> None:
     # Verify that node_name is the equivalent dbt one
     model = context.snapshots[model_fqn].model
     assert model.dbt_name == "model.test_project.simple_model"
+
+
+@pytest.mark.slow
+def test_jinja_config_no_query(tmp_path, create_empty_project):
+    project_dir, model_dir = create_empty_project()
+
+    # model definition contains only a comment and non-SQL jinja
+    model_contents = "/* comment */ {{ config(materialized='table') }}"
+    model_file = model_dir / "comment_config_model.sql"
+    with open(model_file, "w", encoding="utf-8") as f:
+        f.write(model_contents)
+
+    schema_yaml = {"version": 2, "models": [{"name": "comment_config_model"}]}
+    schema_file = model_dir / "schema.yml"
+    with open(schema_file, "w", encoding="utf-8") as f:
+        YAML().dump(schema_yaml, f)
+
+    context = Context(paths=project_dir)
+
+    # loads without error and contains empty query (which will error at runtime)
+    assert not context.snapshots['"local"."main"."comment_config_model"'].model.render_query()