Fix attr completions in the context of param error recovery, fixes #313

Author: davidhalter

crates/parsa_python/src/lib.rs

@@ -405,7 +405,7 @@ create_grammar!(
         | ",".(kwarg | double_starred_expression)+ ","?
     starred_expression: "*" expression
     double_starred_expression: "**" expression
-    kwarg: Name "=" expression
+    kwarg: Name "=" expression | atom "." NeverMatch
 
     // ASSIGNMENT TARGETS
     // ==================

crates/parsa_python/src/tokenizer.rs

@@ -82,7 +82,10 @@ pub fn is_identifier(s: &str) -> bool {
 
 create_terminals!(struct PyTerminal, enum TerminalType,
                   [Name, Operator, String, Bytes, Number, Endmarker, Newline, ErrorToken,
-                   Indent, Dedent, ErrorDedent, FStringStart, FStringString, FStringEnd]);
+                   Indent, Dedent, ErrorDedent, FStringStart, FStringString, FStringEnd,
+                   // This is never generated by the tokenizer, but can be used in the grammar to
+                   // generate error statements
+                   NeverMatch]);
 
 #[derive(Default, Debug)]
 pub struct PythonTokenizer<'a> {

crates/zuban_python/tests/jedilike/main.rs

@@ -42,7 +42,7 @@ lazy_static::lazy_static! {
         ("__init__.py", 1),
         ("isinstance.py", 2),
         ("lambdas.py", 18),
-        ("named_param.py", 10),
+        ("named_param.py", 12),
         ("ordering.py", 4),
         ("pep0484_typing.py", 3),
         ("pep0484_decorators.py", 2),

crates/zuban_python/tests/mypylike/tests/completion.test

@@ -442,3 +442,23 @@ import zuba
 [file zuban-folder/something.py]
 [out]
 __main__.py:5:complete -> []
+
+[case enum_completion_in_function_call_context]
+# flags: --no-typecheck
+# From GH #313
+from enum import StrEnum
+
+class FooStr(StrEnum):
+    SOME_FIELD: str
+    ANOTHER_FIELD: int
+
+def some_function():
+    pass
+
+#? complete --filter SOME_FIELD --filter ANOTHER_FIELD --filter strip --filter value
+some_function(FooStr.
+#? complete
+some_function(FooStr.SOME
+[out]
+__main__.py:13:complete -> [ANOTHER_FIELD, SOME_FIELD, strip, value]
+__main__.py:15:complete -> [SOME_FIELD]