fix: static list of structs as arg (#2515)

* fix: allow list of struct types as fn argument

* test: list of struct args

* test: dynamic subtype in struct, list of structs arg

tests/parser/types/test_lists.py

@@ -362,3 +362,36 @@ def foo() -> (uint256, uint256[3], uint256[2]):
     """
     c = get_contract(code)
     assert c.foo() == [666, [1, 2, 3], [88, 12]]
+
+
+def test_list_of_structs_arg(get_contract):
+    code = """
+struct Foo:
+    x: uint256
+    y: uint256
+
+@external
+def bar(_baz: Foo[3]) -> uint256:
+    sum: uint256 = 0
+    for i in range(3):
+        sum += _baz[i].x * _baz[i].y
+    return sum
+    """
+    c = get_contract(code)
+    c_input = [[x, y] for x, y in zip(range(3), range(3))]
+    assert c.bar(c_input) == 5  # 0 * 0 + 1 * 1 + 2 * 2
+
+
+def test_list_of_structs_arg_with_dynamic_type(get_contract):
+    code = """
+struct Foo:
+    x: uint256
+    _msg: String[32]
+
+@external
+def bar(_baz: Foo[3]) -> String[96]:
+    return concat(_baz[0]._msg, _baz[1]._msg, _baz[2]._msg)
+    """
+    c = get_contract(code)
+    c_input = [[i, msg] for i, msg in enumerate(("Hello ", "world", "!!!!"))]
+    assert c.bar(c_input) == "Hello world!!!!"

vyper/old_codegen/types/types.py

@@ -162,7 +162,7 @@ def canonicalize_type(t, is_indexed=False):
         return byte_type
 
     if isinstance(t, ListType):
-        if not isinstance(t.subtype, (ListType, BaseType)):
+        if not isinstance(t.subtype, (ListType, BaseType, StructType)):
             raise InvalidType(f"List of {t.subtype} not allowed")
         return canonicalize_type(t.subtype) + f"[{t.count}]"