Backport SDL syntax for multiple interfaces…

Equivalent to graphql/graphql-js#1169
(excluding the 'allowLegacySDLImplementsInterface' option)

Author: cpmsmith

graphql/language/lexer.py

@@ -76,6 +76,7 @@ class TokenKind(object):
     INT = 17
     FLOAT = 18
     STRING = 19
+    AMP = 20
 
 
 def get_token_desc(token):
@@ -111,6 +112,7 @@ def get_token_kind_desc(kind):
     TokenKind.INT: "Int",
     TokenKind.FLOAT: "Float",
     TokenKind.STRING: "String",
+    TokenKind.AMP: "&",
 }
 
 
@@ -135,6 +137,7 @@ def char_code_at(s, pos):
     ord("{"): TokenKind.BRACE_L,
     ord("|"): TokenKind.PIPE,
     ord("}"): TokenKind.BRACE_R,
+    ord("&"): TokenKind.AMP,
 }
 
 

graphql/language/parser.py

@@ -718,7 +718,7 @@ def parse_implements_interfaces(parser):
         while True:
             types.append(parse_named_type(parser))
 
-            if not peek(parser, TokenKind.NAME):
+            if not skip(parser, TokenKind.AMP):
                 break
 
     return types

graphql/language/printer.py

@@ -169,7 +169,7 @@ def leave_ObjectTypeDefinition(self, node, *args):
             [
                 "type",
                 node.name,
-                wrap("implements ", join(node.interfaces, ", ")),
+                wrap("implements ", join(node.interfaces, " & ")),
                 join(node.directives, " "),
                 block(node.fields),
             ],

graphql/language/tests/test_schema_parser.py

@@ -153,7 +153,7 @@ def test_parses_simple_type_inheriting_interface():
 
 def test_parses_simple_type_inheriting_multiple_interfaces():
     # type: () -> None
-    body = "type Hello implements Wo, rld { }"
+    body = "type Hello implements Wo & rld { }"
     loc = create_loc_fn(body)
     doc = parse(body)
     expected = ast.Document(
@@ -165,15 +165,15 @@ def test_parses_simple_type_inheriting_multiple_interfaces():
                         name=ast.Name(value="Wo", loc=loc(22, 24)), loc=loc(22, 24)
                     ),
                     ast.NamedType(
-                        name=ast.Name(value="rld", loc=loc(26, 29)), loc=loc(26, 29)
+                        name=ast.Name(value="rld", loc=loc(27, 30)), loc=loc(27, 30)
                     ),
                 ],
                 directives=[],
                 fields=[],
-                loc=loc(0, 33),
+                loc=loc(0, 34),
             )
         ],
-        loc=loc(0, 33),
+        loc=loc(0, 34),
     )
     assert doc == expected
 

graphql/utils/schema_printer.py

@@ -128,7 +128,7 @@ def _print_object(type):
     # type: (GraphQLObjectType) -> str
     interfaces = type.interfaces
     implemented_interfaces = (
-        " implements {}".format(", ".join(i.name for i in interfaces))
+        " implements {}".format(" & ".join(i.name for i in interfaces))
         if interfaces
         else ""
     )

graphql/utils/tests/test_extend_schema.py

@@ -568,7 +568,7 @@ def test_extends_objects_by_adding_implemented_new_interfaces():
   fizz: String
 }
 
-type Foo implements SomeInterface, NewInterface {
+type Foo implements SomeInterface & NewInterface {
   name: String
   some: SomeInterface
   tree: [Foo]!
@@ -637,7 +637,7 @@ def test_extends_objects_multiple_times():
   foo: Foo
 }
 
-type Biz implements NewInterface, SomeInterface {
+type Biz implements NewInterface & SomeInterface {
   fizz: String
   buzz: String
   name: String

graphql/utils/tests/test_schema_printer.py

@@ -390,7 +390,7 @@ def test_prints_multiple_interfaces():
   int: Int
 }
 
-type Bar implements Foo, Baaz {
+type Bar implements Foo & Baaz {
   str: String
   int: Int
 }