[RFC] Make operation name optional.

Implements graphql/graphql-spec#99

Closes #6

Author: jhgg

graphql/core/execution/base.py

@@ -32,24 +32,33 @@ def __init__(self, schema, root, document_ast, operation_name, args, request_con
         to execute, which we will pass throughout the other execution
         methods."""
         errors = []
-        operations = {}
+        operation = None
         fragments = {}
-        for statement in document_ast.definitions:
-            if isinstance(statement, ast.OperationDefinition):
-                name = ''
-                if statement.name:
-                    name = statement.name.value
-                operations[name] = statement
-            elif isinstance(statement, ast.FragmentDefinition):
-                fragments[statement.name.value] = statement
-        if not operation_name and len(operations) != 1:
-            raise GraphQLError(
-                'Must provide operation name '
-                'if query contains multiple operations')
-        op_name = operation_name or next(iter(operations.keys()))
-        operation = operations.get(op_name)
+
+        for definition in document_ast.definitions:
+            if isinstance(definition, ast.OperationDefinition):
+                if not operation_name and operation:
+                    raise GraphQLError('Must provide operation name if query contains multiple operations')
+
+                if not operation_name or definition.name and definition.name.value == operation_name:
+                    operation = definition
+
+            elif isinstance(definition, ast.FragmentDefinition):
+                fragments[definition.name.value] = definition
+
+            else:
+                raise GraphQLError(
+                    u'GraphQL cannot execute a request containing a {}.'.format(definition.__class__.__name__),
+                    definition
+                )
+
         if not operation:
-            raise GraphQLError('Unknown operation name: {}'.format(op_name))
+            if operation_name:
+                raise GraphQLError(u'Unknown operation named "{}".'.format(operation_name))
+
+            else:
+                raise GraphQLError('Must provide an operation.')
+
         variables = get_variable_values(schema, operation.variable_definitions or [], args)
 
         self.schema = schema

graphql/core/language/parser.py

@@ -199,11 +199,17 @@ def parse_operation_definition(parser):
             selection_set=parse_selection_set(parser),
             loc=loc(parser, start)
         )
+
     operation_token = expect(parser, TokenKind.NAME)
     operation = operation_token.value
+
+    name = None
+    if peek(parser, TokenKind.NAME):
+        name = parse_name(parser)
+
     return ast.OperationDefinition(
         operation=operation,
-        name=parse_name(parser),
+        name=name,
         variable_definitions=parse_variable_definitions(parser),
         directives=parse_directives(parser),
         selection_set=parse_selection_set(parser),

tests/core_language/test_parser.py

@@ -43,7 +43,7 @@ def test_parse_provides_useful_errors():
 def test_parse_provides_useful_error_when_using_source():
     with raises(LanguageError) as excinfo:
         parse(Source('query', 'MyQuery.graphql'))
-    assert 'Syntax Error MyQuery.graphql (1:6) Expected Name, found EOF' in str(excinfo.value)
+    assert 'Syntax Error MyQuery.graphql (1:6) Expected {, found EOF' in str(excinfo.value)
 
 
 def test_parses_variable_inline_values():
@@ -134,6 +134,14 @@ def test_parses_kitchen_sink():
     parse(KITCHEN_SINK)
 
 
+def test_parses_anonymous_operations():
+    parse('''
+        mutation {
+            mutationField
+        }
+    ''')
+
+
 def test_parse_creates_ast():
     source = Source("""{
   node(id: 4) {