Fix top level keys handling when building

tests/test_build.py

@@ -79,6 +79,7 @@ def test_build_example(example):
 
     doc.add(nl())
     doc.add(comment("Products"))
+    doc.add(nl())
 
     products = aot()
     doc["products"] = products
@@ -128,3 +129,20 @@ def test_append_table_after_multiple_indices():
     """
     doc = parse(content)
     doc.append("foobar", {"name": "John"})
+
+
+def test_top_level_keys_are_put_at_the_root_of_the_document():
+    doc = document()
+    doc.add(comment("Comment"))
+    doc["foo"] = {"name": "test"}
+    doc["bar"] = 1
+
+    expected = """\
+# Comment
+bar = 1
+
+[foo]
+name = "test"
+"""
+
+    assert doc.as_string()

tomlkit/container.py

@@ -112,8 +112,6 @@ def append(self, key, item):  # type: (Union[Key, str, None], Item) -> Container
         if isinstance(item, AoT) and self._body and not self._parsed:
             if item and "\n" not in item[0].trivia.indent:
                 item[0].trivia.indent = "\n" + item[0].trivia.indent
-            else:
-                self.append(None, Whitespace("\n"))
 
         if key is not None and key in self:
             current_idx = self._map[key]
@@ -211,7 +209,7 @@ def append(self, key, item):  # type: (Union[Key, str, None], Item) -> Container
 
             if key_after is not None:
                 if isinstance(key_after, int):
-                    if key_after + 1 < len(self._body) - 1:
+                    if key_after + 1 < len(self._body):
                         return self._insert_at(key_after + 1, key, item)
                     else:
                         previous_item = self._body[-1][1]