handle multi-line fn defs in signatuer lookup

vyper_lsp/analyzer/AstAnalyzer.py

@@ -57,45 +57,17 @@ def __init__(self, ast: AST) -> None:
         else:
             self.diagnostics_enabled = True
 
-    def signature_help(
-        self, doc: Document, params: SignatureHelpParams
+    def _handle_internal_fn_signature(
+        self, doc: Document, current_line: str, fn_name: str
     ) -> Optional[SignatureHelp]:
-        # TODO: Implement checking external functions, module functions, and interfaces
-        current_line = doc.lines[params.position.line]
-        expression = get_expression_at_cursor(
-            current_line, params.position.character - 1
-        )
-        parsed = utils.parse_fncall_expression(expression)
-        if parsed is None:
-            return None
-        module, fn_name = parsed
-
-        logger.info(f"looking up function {fn_name} in module {module}")
-        if module in self.ast.imports:
-            logger.info("found module")
-            if fn := self.ast.imports[module].functions[fn_name]:
-                logger.info(f"args: {fn.arguments}")
-
-        # this returns for all external functions
-        if module != "self":
-            return None
-
         node = self.ast.find_function_declaration_node_for_name(fn_name)
         if not node:
             return None
 
         fn_name = node.name
         parameters = []
-        line = doc.lines[node.lineno - 1]
-
-        decl_str = f"def {fn_name}("
-        search_start_line_no = 0
 
-        while not line.startswith(decl_str):
-            line = doc.lines[search_start_line_no]
-            search_start_line_no += 1
-
-        fn_label = line.removeprefix("def ").removesuffix(":\n")
+        fn_label = node.node_source_code.split(":\n")[0].removeprefix("def ")
 
         for arg in node.args.args:
             start_index = fn_label.find(arg.arg)
@@ -116,6 +88,29 @@ def signature_help(
             active_signature=0,
         )
 
+    def signature_help(
+        self, doc: Document, params: SignatureHelpParams
+    ) -> Optional[SignatureHelp]:
+        # TODO: Implement checking external functions, module functions, and interfaces
+        current_line = doc.lines[params.position.line]
+        expression = get_expression_at_cursor(
+            current_line, params.position.character - 1
+        )
+        parsed = utils.parse_fncall_expression(expression)
+        if parsed is None:
+            return None
+        module, fn_name = parsed
+
+        logger.info(f"looking up function {fn_name} in module {module}")
+        if module in self.ast.imports:
+            logger.info("found module")
+            if fn := self.ast.imports[module].functions[fn_name]:
+                logger.info(f"args: {fn.arguments}")
+
+        # this returns for all external functions
+        if module == "self":
+            return self._handle_internal_fn_signature(doc, current_line, fn_name)
+
     def _dot_completions_for_element(
         self, element: str, top_level_node=None, line: str = ""
     ) -> List[CompletionItem]:

vyper_lsp/ast.py

@@ -263,7 +263,9 @@ def get_attributes_for_symbol(self, symbol: str):
 
         return []
 
-    def find_function_declaration_node_for_name(self, function: str):
+    def find_function_declaration_node_for_name(
+        self, function: str
+    ) -> Optional[nodes.FunctionDef]:
         for node in self.get_descendants(nodes.FunctionDef):
             name_match = node.name == function
             not_interface_declaration = not isinstance(