feat: add Postgres SQL validator (#11538)

* Add Postgres SQL validator

* Strip line number from message

* Add unit tests

* Run tests only with postgres backend

* Add dep

* Add dep to bashlib

tests/sql_validator_tests.py

@@ -15,6 +15,7 @@
 # specific language governing permissions and limitations
 # under the License.
 # isort:skip_file
+# pylint: disable=invalid-name, no-self-use
 """Unit tests for Sql Lab"""
 import unittest
 from unittest.mock import MagicMock, patch
@@ -22,10 +23,10 @@ from unittest.mock import MagicMock, patch
 import pytest
 from pyhive.exc import DatabaseError
 
-import tests.test_app
 from superset import app
 from superset.sql_validators import SQLValidationAnnotation
 from superset.sql_validators.base import BaseSQLValidator
+from superset.sql_validators.postgres import PostgreSQLValidator
 from superset.sql_validators.presto_db import (
     PrestoDBSQLValidator,
     PrestoSQLValidationError,
@@ -211,5 +212,33 @@ class TestPrestoValidator(SupersetTestCase):
         self.assertIn("no SQL validator is configured", resp["error"])
 
 
+class TestPostgreSQLValidator(SupersetTestCase):
+    def test_valid_syntax(self):
+        if get_example_database().backend != "postgresql":
+            return
+
+        mock_database = MagicMock()
+        annotations = PostgreSQLValidator.validate(
+            sql='SELECT 1, "col" FROM "table"', schema="", database=mock_database
+        )
+        assert annotations == []
+
+    def test_invalid_syntax(self):
+        if get_example_database().backend != "postgresql":
+            return
+
+        mock_database = MagicMock()
+        annotations = PostgreSQLValidator.validate(
+            sql='SELECT 1, "col"\nFROOM "table"', schema="", database=mock_database
+        )
+
+        assert len(annotations) == 1
+        annotation = annotations[0]
+        assert annotation.line_number == 2
+        assert annotation.start_column is None
+        assert annotation.end_column is None
+        assert annotation.message == 'ERROR: syntax error at or near """'
+
+
 if __name__ == "__main__":
     unittest.main()