fix: find top-level node when adding new line

also add test for struct member completion

tests/test_completions.py

@@ -41,6 +41,41 @@ def baz():
     assert "foo" in [c.label for c in completions.items]
 
 
+def test_completions_struct_members(ast):
+    src = """
+struct Foo:
+    bar: uint256
+    baz: uint256
+
+@internal
+def foo():
+    return
+
+@external
+def bar():
+    self.foo()
+
+@external
+def baz():
+    g: Foo = Foo(bar=12, baz=13)
+"""
+    ast.build_ast(src)
+
+    src += """
+    g.
+"""
+    doc = Document(uri="<inline source code>", source=src)
+    pos = Position(line=17, character=6)
+    context = CompletionContext(trigger_character=".", trigger_kind=2)
+    params = CompletionParams(
+        text_document=TextDocumentIdentifier(uri=doc.uri), position=pos, context=context
+    )
+
+    analyzer = CompletionHandler(ast)
+    completions = analyzer._get_completions_in_doc(doc, params)
+    assert len(completions.items) == 2
+
+
 def test_completions_enum_variant(ast):
     src = """
 flag Foo:

vyper_lsp/ast.py

@@ -334,10 +334,17 @@ def find_nodes_referencing_struct(self, struct: str):
         return return_nodes
 
     def find_top_level_node_at_pos(self, pos: Position) -> Optional[VyperNode]:
-        for node in self.get_top_level_nodes():
+        nodes = self.get_top_level_nodes()
+        for node in nodes:
             if node.lineno <= pos.line and pos.line <= node.end_lineno:
                 return node
 
+        # return node with highest lineno if no node found
+        if nodes:
+            # sort
+            nodes.sort(key=lambda x: x.lineno, reverse=True)
+            return nodes[0]
+
         return None
 
     def find_nodes_referencing_symbol(self, symbol: str):