[RFC] Make operation name optional.

src/execution/execute.js

@@ -174,7 +174,8 @@ function buildExecutionContext(
             'Must provide operation name if query contains multiple operations.'
           );
         }
-        if (!operationName || definition.name.value === operationName) {
+        if (!operationName ||
+            definition.name && definition.name.value === operationName) {
           operation = definition;
         }
         break;

src/language/__tests__/parser.js

@@ -92,7 +92,7 @@ fragment MissingOn Type
   it('parse provides useful error when using source', () => {
     expect(
       () => parse(new Source('query', 'MyQuery.graphql'))
-    ).to.throw('Syntax Error MyQuery.graphql (1:6) Expected Name, found EOF');
+    ).to.throw('Syntax Error MyQuery.graphql (1:6) Expected {, found EOF');
   });
 
   it('parses variable inline values', () => {
@@ -193,6 +193,14 @@ fragment ${fragmentName} on Type {
     `)).to.not.throw();
   });
 
+  it('parses anonymous operations', () => {
+    expect(() => parse(`
+      mutation {
+        mutationField
+      }
+    `)).to.not.throw();
+  });
+
   it('parse creates ast', () => {
 
     var source = new Source(`{

src/language/parser.js

@@ -215,7 +215,7 @@ function parseDefinition(parser): Definition {
 /**
  * OperationDefinition :
  *  - SelectionSet
- *  - OperationType Name VariableDefinitions? Directives? SelectionSet
+ *  - OperationType Name? VariableDefinitions? Directives? SelectionSet
  *
  * OperationType : one of query mutation
  */
@@ -234,10 +234,14 @@ function parseOperationDefinition(parser): OperationDefinition {
   }
   var operationToken = expect(parser, TokenKind.NAME);
   var operation = operationToken.value;
+  var name;
+  if (peek(parser, TokenKind.NAME)) {
+    name = parseName(parser);
+  }
   return {
     kind: OPERATION_DEFINITION,
     operation,
-    name: parseName(parser),
+    name,
     variableDefinitions: parseVariableDefinitions(parser),
     directives: parseDirectives(parser),
     selectionSet: parseSelectionSet(parser),

src/utilities/getOperationAST.js

@@ -33,7 +33,7 @@ export function getOperationAST(
           return null;
         }
         operation = definition;
-      } else if (definition.name.value === operationName) {
+      } else if (definition.name && definition.name.value === operationName) {
         return definition;
       }
     }