Work around spec bugs for PowerShellEditorServices (#1181)

- The "tags" in a CompletionItem response are null (invalid per spec)
- The "signatures" in a textDocument/signatureHelp response is null (invalid per spec)

See: PowerShell/PowerShellEditorServices#1324
See: PowerShell/PowerShellEditorServices#1325

Co-authored-by: Предраг Николић / Predrag Nikolic <[email protected]>

Author: rwols

plugin/completion.py

@@ -137,7 +137,12 @@ def resolve(completion_list: sublime.CompletionList, items: List[sublime.Complet
 
 
 def is_deprecated(item: dict) -> bool:
-    return item.get("deprecated", False) or CompletionItemTag.Deprecated in item.get("tags", [])
+    if item.get("deprecated", False):
+        return True
+    tags = item.get("tags")
+    if isinstance(tags, list):
+        return CompletionItemTag.Deprecated in tags
+    return False
 
 
 class CompletionHandler(LSPViewEventListener):

plugin/core/signature_help.py

@@ -163,20 +163,17 @@ def _build_overload_selector(self) -> str:
 def create_signature_help(response: Optional[dict]) -> Optional[SignatureHelp]:
     if response is None:
         return None
-
-    signatures = list(parse_signature_information(signature) for signature in response.get("signatures", []))
-    active_signature = response.get("activeSignature", -1)
-    active_parameter = response.get("activeParameter", -1)
-
+    signatures = response.get("signatures") or []
+    signatures = [parse_signature_information(signature) for signature in signatures]
     if signatures:
+        active_signature = response.get("activeSignature", -1)
+        active_parameter = response.get("activeParameter", -1)
         if not 0 <= active_signature < len(signatures):
             debug("activeSignature {} not a valid index for signatures length {}".format(
                 active_signature, len(signatures)))
             active_signature = 0
-
         return SignatureHelp(signatures, active_signature, active_parameter)
-    else:
-        return None
+    return None
 
 
 def find_params_to_split_at(label: str) -> List[int]: