Add tests for directives

Author: Cito

README.md

@@ -13,7 +13,7 @@ a query language for APIs created by Facebook.
 
 The current version 1.0.0rc2 of GraphQL-core-next is up-to-date with GraphQL.js
 version 14.0.0rc2. All parts of the API are covered by an extensive test
-suite of currently 1569 unit tests.
+suite of currently 1585 unit tests.
 
 
 ## Documentation

graphql/type/directives.py

@@ -34,7 +34,7 @@ def __init__(self, name: str,
         elif not isinstance(name, str):
             raise TypeError('The directive name must be a string.')
         if not isinstance(locations, (list, tuple)):
-            raise TypeError('{name} locations must be a list/tuple.')
+            raise TypeError(f'{name} locations must be a list/tuple.')
         if not all(isinstance(value, DirectiveLocation)
                    for value in locations):
             try:
@@ -60,7 +60,7 @@ def __init__(self, name: str,
                     else GraphQLArgument(cast(GraphQLInputType, value))
                     for name, value in args.items()}
         if description is not None and not isinstance(description, str):
-            raise TypeError('f{name} description must be a string.')
+            raise TypeError(f'{name} description must be a string.')
         if ast_node and not isinstance(ast_node, ast.DirectiveDefinitionNode):
             raise TypeError(
                 f'{name} AST node must be a DirectiveDefinitionNode.')

tests/type/test_directives.py

@@ -0,0 +1,137 @@
+from pytest import raises
+
+from graphql.language import DirectiveLocation, DirectiveDefinitionNode, Node
+from graphql.type import (
+    GraphQLArgument, GraphQLDirective, GraphQLString, GraphQLSkipDirective,
+    is_directive, is_specified_directive)
+
+
+def describe_graphql_directive():
+
+    def can_create_instance():
+        arg = GraphQLArgument(GraphQLString, description='arg description')
+        node = DirectiveDefinitionNode()
+        locations = [DirectiveLocation.SCHEMA, DirectiveLocation.OBJECT]
+        directive = GraphQLDirective(
+            name='test',
+            locations=[DirectiveLocation.SCHEMA, DirectiveLocation.OBJECT],
+            args={'arg': arg},
+            description='test description',
+            ast_node=node)
+        assert directive.name == 'test'
+        assert directive.locations == locations
+        assert directive.args == {'arg': arg}
+        assert directive.description == 'test description'
+        assert directive.ast_node is node
+
+    def has_str():
+        directive = GraphQLDirective('test', [])
+        assert str(directive) == '@test'
+
+    def has_repr():
+        directive = GraphQLDirective('test', [])
+        assert repr(directive) == '<GraphQLDirective(@test)>'
+
+    def accepts_strings_as_locations():
+        # noinspection PyTypeChecker
+        directive = GraphQLDirective(
+            name='test', locations=['SCHEMA', 'OBJECT'])  # type: ignore
+        assert directive.locations == [
+            DirectiveLocation.SCHEMA, DirectiveLocation.OBJECT]
+
+    def accepts_input_types_as_arguments():
+        # noinspection PyTypeChecker
+        directive = GraphQLDirective(
+            name='test', locations=[],
+            args={'arg': GraphQLString})  # type: ignore
+        arg = directive.args['arg']
+        assert isinstance(arg, GraphQLArgument)
+        assert arg.type is GraphQLString
+
+    def does_not_accept_a_bad_name():
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective(None, locations=[])  # type: ignore
+        assert str(exc_info.value) == 'Directive must be named.'
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective({'bad': True}, locations=[])  # type: ignore
+        assert str(exc_info.value) == 'The directive name must be a string.'
+
+    def does_not_accept_bad_locations():
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective('test', locations='bad')  # type: ignore
+        assert str(exc_info.value) == 'test locations must be a list/tuple.'
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective('test', locations=['bad'])  # type: ignore
+        assert str(exc_info.value) == (
+            'test locations must be DirectiveLocation objects.')
+
+    def does_not_accept_bad_args():
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective(
+                'test', locations=[], args=['arg'])  # type: ignore
+        assert str(exc_info.value) == (
+            'test args must be a dict with argument names as keys.')
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective(
+                'test', locations=[],
+                args={1: GraphQLArgument(GraphQLString)})  # type: ignore
+        assert str(exc_info.value) == (
+            'test args must be a dict with argument names as keys.')
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective(
+                'test', locations=[],
+                args={'arg': GraphQLDirective('test', [])})  # type: ignore
+        assert str(exc_info.value) == (
+            'test args must be GraphQLArgument or input type objects.')
+
+    def does_not_accept_a_bad_description():
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective(
+                'test', locations=[],
+                description={'bad': True})  # type: ignore
+        assert str(exc_info.value) == 'test description must be a string.'
+
+    def does_not_accept_a_bad_ast_node():
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            GraphQLDirective(
+                'test', locations=[],
+                ast_node=Node())  # type: ignore
+        assert str(exc_info.value) == (
+            'test AST node must be a DirectiveDefinitionNode.')
+
+
+def describe_directive_predicates():
+
+    def describe_is_directive():
+
+        def returns_true_for_directive():
+            directive = GraphQLDirective('test', [])
+            assert is_directive(directive) is True
+
+        def returns_false_for_type_class_rather_than_instance():
+            assert is_directive(GraphQLDirective) is False
+
+        def returns_false_for_other_instances():
+            assert is_directive(GraphQLString) is False
+
+        def returns_false_for_random_garbage():
+            assert is_directive(None) is False
+            assert is_directive({'what': 'is this'}) is False
+
+    def describe_is_specified_directive():
+
+        def returns_true_for_specified_directive():
+            assert is_specified_directive(GraphQLSkipDirective) is True
+
+        def returns_false_for_unspecified_directive():
+            directive = GraphQLDirective('test', [])
+            assert is_specified_directive(directive) is False