Fix missing EOL when formatting SQL files (#260)

Fixes #245

---------

Co-authored-by: Eric Vergnaud <eric.vergnaud@databricks.com>

Author: ericvergnaud

src/databricks/labs/lsql/dashboards.py

@@ -429,6 +429,7 @@ def format(content: str, *, max_text_width: int = 120, normalize_case: bool = Tr
             normalize_case : bool, optional (default: True)
                 If the query identifiers should be normalized to lower case
         """
+        has_eol = content.endswith("\n")
         try:
             parsed_query = sqlglot.parse(content, dialect=_SQL_DIALECT)
         except sqlglot.ParseError:
@@ -453,7 +454,7 @@ def format(content: str, *, max_text_width: int = 120, normalize_case: bool = Tr
         if "$" in content:
             # replace ${x} with $x, because we use it in UCX view definitions for now
             formatted_query = re.sub(r"\${(\w+)}", r"$\1", formatted_query)
-        return formatted_query
+        return formatted_query + ("\n" if has_eol else "")
 
     def _get_abstract_syntax_tree(self) -> sqlglot.Expression | None:
         try:

tests/unit/test_dashboards.py

@@ -829,7 +829,12 @@ def test_query_tile_keeps_original_query(tmp_path):
     ],
 )
 def test_query_formats(query, query_formatted):
-    assert QueryTile.format(query) == query_formatted
+    assert QueryTile.format(query).strip() == query_formatted.strip()
+
+
+def test_query_format_preserves_eol():
+    assert not QueryTile.format("SELECT x, y FROM a, b").endswith("\n")
+    assert QueryTile.format("SELECT x, y FROM a, b\n").endswith("\n")
 
 
 def test_query_formats_no_normalize():