Provide specified_directives as ReadOnlyList (#31)

Author: Cito

README.md

@@ -13,7 +13,7 @@ a query language for APIs created by Facebook.
 [![Code Style](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
 
 The current version 1.0.3 of GraphQL-core-next is up-to-date with GraphQL.js version
-14.2.1. All parts of the API are covered by an extensive test suite of currently 1753
+14.2.1. All parts of the API are covered by an extensive test suite of currently 1758
 unit tests.
 
 

graphql/pyutils/__init__.py

@@ -21,6 +21,7 @@
 from .or_list import or_list
 from .quoted_or_list import quoted_or_list
 from .suggestion_list import suggestion_list
+from .read_only_list import ReadOnlyError, ReadOnlyList
 
 __all__ = [
     "camel_to_snake",
@@ -38,4 +39,6 @@
     "or_list",
     "quoted_or_list",
     "suggestion_list",
+    "ReadOnlyError",
+    "ReadOnlyList",
 ]

graphql/pyutils/read_only_list.py

@@ -0,0 +1,53 @@
+__all__ = ["ReadOnlyError", "ReadOnlyList"]
+
+
+class ReadOnlyError(TypeError):
+    """Error when trying to write to a ReadOnlyList."""
+
+
+class ReadOnlyList(list):
+    """List that can only be read, but not changed."""
+
+    def __delitem__(self, key):
+        raise ReadOnlyError
+
+    def __setitem__(self, key, value):
+        raise ReadOnlyError
+
+    def __add__(self, value):
+        if isinstance(value, tuple):
+            value = list(value)
+        return list.__add__(self, value)
+
+    def __iadd__(self, value):
+        raise ReadOnlyError
+
+    def __mul__(self, value):
+        return list.__mul__(self, value)
+
+    def __imul__(self, value):
+        raise ReadOnlyError
+
+    def append(self, x):
+        raise ReadOnlyError
+
+    def extend(self, iterable):
+        raise ReadOnlyError
+
+    def insert(self, i, x):
+        raise ReadOnlyError
+
+    def remove(self, x):
+        raise ReadOnlyError
+
+    def pop(self, i=None):
+        raise ReadOnlyError
+
+    def clear(self):
+        raise ReadOnlyError
+
+    def sort(self, *, key=None, reverse=False):
+        raise ReadOnlyError
+
+    def reverse(self):
+        raise ReadOnlyError

graphql/type/directives.py

@@ -1,7 +1,7 @@
 from typing import Any, Dict, Sequence, cast
 
 from ..language import ast, DirectiveLocation
-from ..pyutils import inspect
+from ..pyutils import inspect, ReadOnlyList
 from .definition import GraphQLArgument, GraphQLInputType, GraphQLNonNull, is_input_type
 from .scalars import GraphQLBoolean, GraphQLString
 
@@ -166,10 +166,8 @@ def assert_directive(directive: Any) -> GraphQLDirective:
 
 
 # The full list of specified directives.
-specified_directives = (
-    GraphQLIncludeDirective,
-    GraphQLSkipDirective,
-    GraphQLDeprecatedDirective,
+specified_directives = ReadOnlyList(
+    [GraphQLIncludeDirective, GraphQLSkipDirective, GraphQLDeprecatedDirective]
 )
 
 

graphql/type/schema.py

@@ -72,7 +72,7 @@ class GraphQLSchema:
 
         MyAppSchema = GraphQLSchema(
           ...
-          directives=specifiedDirectives + [myCustomDirective])
+          directives=specified_directives + [my_custom_directive])
     """
 
     query_type: Optional[GraphQLObjectType]

tests/pyutils/test_read_only_list.py

@@ -0,0 +1,80 @@
+from pytest import raises
+
+from graphql.pyutils import ReadOnlyError, ReadOnlyList
+
+
+def describe_read_only_list():
+    def can_read():
+        rol = ReadOnlyList([1, 2, 3])
+        assert rol == [1, 2, 3]
+        assert list(i for i in rol) == rol
+        assert rol.copy() == rol
+        assert 2 in rol
+        assert 4 not in rol
+        assert rol + [4, 5] == [1, 2, 3, 4, 5]
+        assert [4, 5] + rol == [4, 5, 1, 2, 3]
+        assert rol * 2 == [1, 2, 3, 1, 2, 3]
+        assert 2 * rol == [1, 2, 3, 1, 2, 3]
+        assert rol[1] == 2
+        with raises(IndexError):
+            rol[3]
+        assert rol[1:4] == [2, 3]
+        assert rol[::2] == [1, 3]
+        assert len(rol) == 3
+        assert min(rol) == 1
+        assert max(rol) == 3
+        assert sum(rol) == 6
+        assert rol.index(2) == 1
+        with raises(ValueError):
+            rol.index(4)
+        assert rol.count(2) == 1
+        assert rol.count(4) == 0
+        assert list(reversed(rol)) == [3, 2, 1]
+        assert sorted(rol) == [1, 2, 3]
+
+    def cannot_write():
+        rol = ReadOnlyList([1, 2, 3])
+        with raises(ReadOnlyError):
+            rol[1] = 4
+        with raises(ReadOnlyError):
+            rol[1:4] = [4]
+        with raises(ReadOnlyError):
+            del rol[1]
+        with raises(ReadOnlyError):
+            del rol[1:4]
+        with raises(ReadOnlyError):
+            rol[1::2] = [4]
+        with raises(ReadOnlyError):
+            del rol[::2]
+        with raises(ReadOnlyError):
+            rol.append(4)
+        with raises(ReadOnlyError):
+            rol.clear()
+        with raises(ReadOnlyError):
+            rol.extend([4])
+        with raises(ReadOnlyError):
+            rol += [4]
+        with raises(ReadOnlyError):
+            rol *= 2
+        with raises(ReadOnlyError):
+            rol.insert(1, 4)
+        with raises(ReadOnlyError):
+            rol.pop()
+        with raises(ReadOnlyError):
+            rol.remove(2)
+        with raises(ReadOnlyError):
+            rol.sort()
+        with raises(ReadOnlyError):
+            rol.reverse()
+
+    def can_add_rol():
+        rol1 = ReadOnlyList([1, 2])
+        rol2 = ReadOnlyList([3, 4])
+        assert rol1 + rol2 == [1, 2, 3, 4]
+
+    def can_add_tuple():
+        rol = ReadOnlyList([1, 2])
+        assert rol + (3, 4) == [1, 2, 3, 4]
+
+    def read_only_error_is_type_error():
+        assert issubclass(ReadOnlyError, TypeError)

tests/utilities/test_extend_schema.py

@@ -117,7 +117,7 @@
         },
     ),
     types=[FooType, BarType],
-    directives=specified_directives + (FooDirective,),
+    directives=specified_directives + [FooDirective],
 )