fix: keep a marker on its own line bound to the statement directly below it

tests/code_coverage_tests/check_migrations_no_data_rewrites.py

@@ -197,12 +197,18 @@ class Markers:
         if start <= marker.start < end:
             return True
         if marker.standalone:
-            return self.only_separators(marker.end, start)
+            return self.on_the_line_below(marker.end, start)
         return self.only_separators(end, marker.start)
 
+    def on_the_line_below(self, start: int, end: int) -> bool:
+        """Whether a marker on its own line is written directly above the statement, which means
+        one line break and nothing else that carries meaning. A blank line between the two leaves
+        the marker reading as a note about the file rather than a bound on what follows it."""
+        return self.only_separators(start, end) and self.sql[start:end].count("\n") == 1
+
     def only_separators(self, start: int, end: int) -> bool:
         """Whether nothing but statement separators lie between two points, which is what makes a
-        marker and a statement adjacent whatever whitespace and line breaks sit between them."""
+        marker and the statement it follows adjacent however they are laid out."""
         return start <= end and not self.sql[start:end].strip(" \t\r\n;")
 
 

tests/test_litellm/test_check_migrations_no_data_rewrites.py

@@ -375,6 +375,11 @@ class TestEscapeHatch:
         assert _keywords(tmp_path, sql) == ("UPDATE",)
         assert _scan(tmp_path, sql)[0].line == 1
 
+    def test_a_marker_a_blank_line_above_a_statement_does_not_exempt_it(self, tmp_path):
+        sql = '-- data-migration-ok: one row\n\nUPDATE "Foo" SET "a" = 1;'
+        assert _keywords(tmp_path, sql) == ("UPDATE",)
+        assert _scan(tmp_path, sql)[0].line == 3
+
     def test_a_trailing_marker_exempts_only_the_statement_it_follows(self, tmp_path):
         sql = 'DELETE FROM "Foo" WHERE "a" = 1; UPDATE "Bar" SET "b" = 2; -- data-migration-ok: one row'
         assert _keywords(tmp_path, sql) == ("DELETE",)
@@ -410,6 +415,11 @@ class TestEscapeHatch:
         assert _keywords(tmp_path, sql) == ("UPDATE",)
         assert _scan(tmp_path, sql)[0].line == 5
 
+    def test_marker_directly_above_a_one_line_do_block_does_not_exempt_its_body(self, tmp_path):
+        sql = '-- data-migration-ok: seeding one default row\nDO $$ BEGIN UPDATE "Foo" SET "a" = 1; END $$;'
+        assert _keywords(tmp_path, sql) == ("UPDATE",)
+        assert _scan(tmp_path, sql)[0].line == 2
+
     def test_marker_on_the_do_line_does_not_exempt_its_body(self, tmp_path):
         sql = (
             "DO $$  -- data-migration-ok: bounded to one row\n"