[RFC] Type condition optional on inline fragments.

Implements graphql/graphql-spec#100

Author: leebyron

src/execution/execute.js

@@ -430,7 +430,11 @@ function doesFragmentConditionMatch(
  fragment: FragmentDefinition | InlineFragment,
  type: GraphQLObjectType
 ): boolean {
- var conditionalType = typeFromAST(exeContext.schema, fragment.typeCondition);
+ var typeConditionAST = fragment.typeCondition;
+ if (!typeConditionAST) {
+ return true;
+ }
+ var conditionalType = typeFromAST(exeContext.schema, typeConditionAST);
  if (conditionalType === type) {
  return true;
  }

src/language/__tests__/kitchen-sink.graphql

@@ -17,6 +17,12 @@ query queryName($foo: ComplexType, $site: Site = MOBILE) {
  }
  }
  }
+ ... @skip(unless: $foo) {
+ id
+ }
+ ... {
+ id
+ }
  }
 }
 

src/language/__tests__/printer.js

@@ -59,6 +59,12 @@ describe('Printer', () => {
  }
  }
  }
+ ... @skip(unless: $foo) {
+ id
+ }
+ ... {
+ id
+ }
  }
 }
 

src/language/__tests__/visitor.js

@@ -321,6 +321,34 @@ describe('Visitor', () => {
  [ 'leave', 'Field', 0, undefined ],
  [ 'leave', 'SelectionSet', 'selectionSet', 'InlineFragment' ],
  [ 'leave', 'InlineFragment', 1, undefined ],
+ [ 'enter', 'InlineFragment', 2, undefined ],
+ [ 'enter', 'Directive', 0, undefined ],
+ [ 'enter', 'Name', 'name', 'Directive' ],
+ [ 'leave', 'Name', 'name', 'Directive' ],
+ [ 'enter', 'Argument', 0, undefined ],
+ [ 'enter', 'Name', 'name', 'Argument' ],
+ [ 'leave', 'Name', 'name', 'Argument' ],
+ [ 'enter', 'Variable', 'value', 'Argument' ],
+ [ 'enter', 'Name', 'name', 'Variable' ],
+ [ 'leave', 'Name', 'name', 'Variable' ],
+ [ 'leave', 'Variable', 'value', 'Argument' ],
+ [ 'leave', 'Argument', 0, undefined ],
+ [ 'leave', 'Directive', 0, undefined ],
+ [ 'enter', 'SelectionSet', 'selectionSet', 'InlineFragment' ],
+ [ 'enter', 'Field', 0, undefined ],
+ [ 'enter', 'Name', 'name', 'Field' ],
+ [ 'leave', 'Name', 'name', 'Field' ],
+ [ 'leave', 'Field', 0, undefined ],
+ [ 'leave', 'SelectionSet', 'selectionSet', 'InlineFragment' ],
+ [ 'leave', 'InlineFragment', 2, undefined ],
+ [ 'enter', 'InlineFragment', 3, undefined ],
+ [ 'enter', 'SelectionSet', 'selectionSet', 'InlineFragment' ],
+ [ 'enter', 'Field', 0, undefined ],
+ [ 'enter', 'Name', 'name', 'Field' ],
+ [ 'leave', 'Name', 'name', 'Field' ],
+ [ 'leave', 'Field', 0, undefined ],
+ [ 'leave', 'SelectionSet', 'selectionSet', 'InlineFragment' ],
+ [ 'leave', 'InlineFragment', 3, undefined ],
  [ 'leave', 'SelectionSet', 'selectionSet', 'Field' ],
  [ 'leave', 'Field', 0, undefined ],
  [ 'leave', 'SelectionSet', 'selectionSet', 'OperationDefinition' ],

src/language/ast.js

@@ -142,7 +142,7 @@ export type FragmentSpread = {
 export type InlineFragment = {
  kind: 'InlineFragment';
  loc?: ?Location;
- typeCondition: NamedType;
+ typeCondition?: ?NamedType;
  directives?: ?Array<Directive>;
  selectionSet: SelectionSet;
 }

src/language/parser.js

@@ -377,25 +377,29 @@ function parseArgument(parser): Argument {
  *
  * FragmentSpread : ... FragmentName Directives?
  *
- * InlineFragment : ... on TypeCondition Directives? SelectionSet
+ * InlineFragment : ... TypeCondition? Directives? SelectionSet
  */
 function parseFragment(parser): FragmentSpread | InlineFragment {
  var start = parser.token.start;
  expect(parser, TokenKind.SPREAD);
- if (parser.token.value === 'on') {
- advance(parser);
+ if (peek(parser, TokenKind.NAME) && parser.token.value !== 'on') {
  return {
- kind: INLINE_FRAGMENT,
- typeCondition: parseNamedType(parser),
+ kind: FRAGMENT_SPREAD,
+ name: parseFragmentName(parser),
  directives: parseDirectives(parser),
- selectionSet: parseSelectionSet(parser),
  loc: loc(parser, start)
  };
  }
+ var typeCondition = null;
+ if (parser.token.value === 'on') {
+ advance(parser);
+ typeCondition = parseNamedType(parser);
+ }
  return {
- kind: FRAGMENT_SPREAD,
- name: parseFragmentName(parser),
+ kind: INLINE_FRAGMENT,
+ typeCondition,
  directives: parseDirectives(parser),
+ selectionSet: parseSelectionSet(parser),
  loc: loc(parser, start)
  };
 }

src/language/printer.js

@@ -55,9 +55,12 @@ var printDocASTReducer = {
  '...' + name + wrap(' ', join(directives, ' ')),
 
  InlineFragment: ({ typeCondition, directives, selectionSet }) =>
- `... on ${typeCondition} ` +
- wrap('', join(directives, ' '), ' ') +
- selectionSet,
+ join([
+ '...',
+ wrap('on ', typeCondition),
+ join(directives, ' '),
+ selectionSet
+ ], ' '),
 
  FragmentDefinition: ({ name, typeCondition, directives, selectionSet }) =>
  `fragment ${name} on ${typeCondition} ` +

src/utilities/TypeInfo.js

@@ -132,7 +132,10 @@ export class TypeInfo {
  break;
  case Kind.INLINE_FRAGMENT:
  case Kind.FRAGMENT_DEFINITION:
- type = typeFromAST(schema, node.typeCondition);
+ var typeConditionAST = node.typeCondition;
+ type = typeConditionAST ?
+ typeFromAST(schema, typeConditionAST) :
+ this.getType();
  this._typeStack.push(type);
  break;
  case Kind.VARIABLE_DEFINITION:

src/validation/__tests__/FieldsOnCorrectType.js

@@ -185,6 +185,9 @@ describe('Validate: Fields on correct type', () => {
  ... on Dog {
  name
  }
+ ... {
+ name
+ }
  }
  `);
  });

src/validation/__tests__/KnownFragmentNames.js

@@ -32,6 +32,9 @@ describe('Validate: Known fragment names', () => {
  ... on Human {
  ...HumanFields2
  }
+ ... {
+ name
+ }
  }
  }
  fragment HumanFields1 on Human {