fix(query): fix getInfo crashing for meta fields

src/query/_shared/getTypeInfo.js

@@ -6,10 +6,6 @@ import {
   getNullableType,
   GraphQLList,
   isCompositeType,
-
-  SchemaMetaFieldDef,
-  TypeMetaFieldDef,
-  TypeNameMetaFieldDef,
 } from 'graphql/type';
 
 import {
@@ -22,6 +18,10 @@ import {
   type GQLType,
   type GQLNamedType,
   type GQLSchema,
+
+  SchemaMetaFieldDef,
+  TypeMetaFieldDef,
+  TypeNameMetaFieldDef,
 } from '../../shared/GQLTypes';
 
 type Info = {

src/query/commands/__tests__/__snapshots__/getHintsAtPosition.test.js.snap

@@ -104,3 +104,28 @@ Array [
   },
 ]
 `;
+
+exports[`show meta field __typename in abstract types interface type 1`] = `
+Array [
+  Object {
+    "description": "",
+    "text": "id",
+    "type": "ID!",
+  },
+  Object {
+    "description": "The name of the current Object type at runtime.",
+    "text": "__typename",
+    "type": "String!",
+  },
+]
+`;
+
+exports[`show meta field __typename in abstract types union type 1`] = `
+Array [
+  Object {
+    "description": "The name of the current Object type at runtime.",
+    "text": "__typename",
+    "type": "String!",
+  },
+]
+`;

src/query/commands/__tests__/__snapshots__/getInfoOfTokenAtPosition.test.js.snap

@@ -106,6 +106,101 @@ Object {
 }
 `;
 
+exports[`meta field __schema 1`] = `
+Object {
+  "contents": Array [
+    "# Access the current type schema of this server.
+(meta-field) __schema: __Schema!",
+    "# A GraphQL Schema defines the capabilities of a GraphQL server. It exposes all
+# available types and directives on the server, as well as the entry points for
+# query, mutation, and subscription operations.
+type __Schema {
+  # A list of all types supported by this server.
+  types: [__Type!]!
+
+  # The type that query operations will be rooted at.
+  queryType: __Type!
+
+  # If this server supports mutation, the type that mutation operations will be rooted at.
+  mutationType: __Type
+
+  # If this server support subscription, the type that subscription operations will be rooted at.
+  subscriptionType: __Type
+
+  # A list of all directives supported by this server.
+  directives: [__Directive!]!
+}",
+  ],
+}
+`;
+
+exports[`meta field __type 1`] = `
+Object {
+  "contents": Array [
+    "# Request the type information of a single type.
+(meta-field) __type(name: String!): __Type",
+    "# The fundamental unit of any GraphQL Schema is the type. There are many kinds of
+# types in GraphQL as represented by the \`__TypeKind\` enum.
+#
+# Depending on the kind of a type, certain fields describe information about that
+# type. Scalar types provide no information beyond a name and description, while
+# Enum types provide their values. Object and Interface types provide the fields
+# they describe. Abstract types, Union and Interface, provide the Object types
+# possible at runtime. List and NonNull types compose other types.
+type __Type {
+  kind: __TypeKind!
+  name: String
+  description: String
+  fields(includeDeprecated: Boolean = false): [__Field!]
+  interfaces: [__Type!]
+  possibleTypes: [__Type!]
+  enumValues(includeDeprecated: Boolean = false): [__EnumValue!]
+  inputFields: [__InputValue!]
+  ofType: __Type
+}",
+  ],
+}
+`;
+
+exports[`meta field __typename when inside Interface Type 1`] = `
+Object {
+  "contents": Array [
+    "# The name of the current Object type at runtime.
+(meta-field) __typename: String!",
+    "# The \`String\` scalar type represents textual data, represented as UTF-8 character
+# sequences. The String type is most often used by GraphQL to represent free-form
+# human-readable text.
+scalar String",
+  ],
+}
+`;
+
+exports[`meta field __typename when inside Object Type 1`] = `
+Object {
+  "contents": Array [
+    "# The name of the current Object type at runtime.
+(meta-field) __typename: String!",
+    "# The \`String\` scalar type represents textual data, represented as UTF-8 character
+# sequences. The String type is most often used by GraphQL to represent free-form
+# human-readable text.
+scalar String",
+  ],
+}
+`;
+
+exports[`meta field __typename when inside Union Type 1`] = `
+Object {
+  "contents": Array [
+    "# The name of the current Object type at runtime.
+(meta-field) __typename: String!",
+    "# The \`String\` scalar type represents textual data, represented as UTF-8 character
+# sequences. The String type is most often used by GraphQL to represent free-form
+# human-readable text.
+scalar String",
+  ],
+}
+`;
+
 exports[`mutations field: Include both input and output type 1`] = `
 Object {
   "contents": Array [

src/query/commands/__tests__/getHintsAtPosition.test.js

@@ -259,3 +259,35 @@ describe('directives', () => {
     ).toMatchSnapshot();
   });
 });
+
+
+describe('show meta field __typename in abstract types', () => {
+  it('interface type', () => {
+    const { sourceText, position } = code(`
+      const a = Relay.QL\`
+        fragment on Node {
+          id
+          __type
+        #-------^
+        }
+      \`
+    `);
+    expect(
+      getHintsAtPosition(schema, sourceText, position, relayConfig),
+    ).toMatchSnapshot();
+  });
+
+  it('union type', () => {
+    const { sourceText, position } = code(`
+      const a = Relay.QL\`
+        fragment on Entity {
+          __type
+        #-------^
+        }
+      \`
+    `);
+    expect(
+      getHintsAtPosition(schema, sourceText, position, relayConfig),
+    ).toMatchSnapshot();
+  });
+});

src/query/commands/__tests__/getInfoOfTokenAtPosition.test.js

@@ -252,3 +252,74 @@ describe('query', () => {
     ).toMatchSnapshot();
   });
 });
+
+describe('meta field __typename', () => {
+  it('when inside Object Type', () => {
+    const { sourceText, position } = code(`
+      const a = Relay.QL\`
+        fragment on Viewer {
+          __typename
+          #----^
+        }
+      \`
+    `);
+    expect(
+      getInfoOfTokenAtPosition(schema, sourceText, position, relayQLParser),
+    ).toMatchSnapshot();
+  });
+  it('when inside Interface Type', () => {
+    const { sourceText, position } = code(`
+      const a = Relay.QL\`
+        fragment on Node {
+          __typename
+          #----^
+        }
+      \`
+    `);
+    expect(
+      getInfoOfTokenAtPosition(schema, sourceText, position, relayQLParser),
+    ).toMatchSnapshot();
+  });
+  it('when inside Union Type', () => {
+    const { sourceText, position } = code(`
+      const a = Relay.QL\`
+        fragment on Entity {
+          __typename
+          #----^
+        }
+      \`
+    `);
+    expect(
+      getInfoOfTokenAtPosition(schema, sourceText, position, relayQLParser),
+    ).toMatchSnapshot();
+  });
+});
+
+test('meta field __schema', () => {
+  const { sourceText, position } = code(`
+    const a = Relay.QL\`
+      query Viewer {
+        __schema
+        #----^
+      }
+    \`
+  `);
+  expect(
+    getInfoOfTokenAtPosition(schema, sourceText, position, relayQLParser),
+  ).toMatchSnapshot();
+});
+
+test('meta field __type', () => {
+  const { sourceText, position } = code(`
+    const a = Relay.QL\`
+      query Viewer {
+        __type
+        #--^
+      }
+    \`
+  `);
+  expect(
+    getInfoOfTokenAtPosition(schema, sourceText, position, relayQLParser),
+  ).toMatchSnapshot();
+});
+

src/query/commands/getHintsAtPosition.js

@@ -9,6 +9,10 @@ import {
   GQLEnumType,
   getNamedType,
   type GQLSchema,
+
+  SchemaMetaFieldDef,
+  TypeMetaFieldDef,
+  TypeNameMetaFieldDef,
 } from '../../shared/GQLTypes';
 import { type QueryParser } from '../../config/GQLConfig';
 import getTokenAtPosition from '../_shared/getTokenAtPosition';
@@ -19,10 +23,6 @@ import {
 
   isInputType,
   isCompositeType,
-
-  SchemaMetaFieldDef,
-  TypeMetaFieldDef,
-  TypeNameMetaFieldDef,
 } from 'graphql/type';
 
 import getTypeInfo from '../_shared/getTypeInfo';

src/shared/GQLTypes.js

@@ -18,8 +18,17 @@ import {
   GraphQLObjectType,
   GraphQLSkipDirective,
   GraphQLDirective,
+  GraphqlField,
+
+  SchemaMetaFieldDef as _SchemaMetaFieldDef,
+  TypeMetaFieldDef as _TypeMetaFieldDef,
+  TypeNameMetaFieldDef as _TypeNameMetaFieldDef,
 } from 'graphql/type';
 
+import { printType } from 'graphql/utilities/schemaPrinter';
+
+import _keyBy from 'lodash/keyBy';
+
 import {
   type TypeDefinitionNode,
   type FieldDefinitionNode,
@@ -48,7 +57,7 @@ export type GQLField = {
   resolve?: any,
   isDeprecated?: boolean,
   deprecationReason?: ?string,
-  node: FieldDefinitionNode,
+  node: ?FieldDefinitionNode,
   print: () => string,
 };
 
@@ -132,15 +141,16 @@ function print(node: ?ASTNode, description: ?string, type: ?string): string {
   ].filter(Boolean).join('\n');
 }
 
-function patchFields(fields) {
-  Object.keys(fields).forEach((name) => {
+function patchFields(fields: Array<GraphqlField>): Array<GQLField> {
+  return Object.keys(fields).map((name) => {
     const field = fields[name];
     field.print = memoize(() => print(field.node, field.description, 'field'));
     field.args = field.args.map((arg, index) => ({
       ...arg,
       node: field.node.arguments[index],
       print: memoize(() => print(field.node.arguments[index], arg.description, 'argument')),
     }));
+    return field;
   });
 }
 
@@ -166,6 +176,44 @@ GQLFloat.print = () => printDescription(GQLFloat.description);
 export const GQLBoolean: GQLScalarType = GraphQLBoolean;
 GQLBoolean.print = () => printDescription(GQLBoolean.description);
 
+const [SchemaMetaFieldDef, TypeMetaFieldDef, TypeNameMetaFieldDef] = [
+  _SchemaMetaFieldDef,
+  _TypeMetaFieldDef,
+  _TypeNameMetaFieldDef,
+].map(field => {
+  const type = getNamedType(field.type);
+  type.print = memoize(() => printType(type));
+
+  return {
+    ...field,
+    print: memoize(() => {
+      // HACK: graphql doesnt expose printField method
+      // so creating fake type and printing it and extracting field string
+      const printedType = printType(
+        new GraphQLObjectType({
+          name: 'Demo',
+          fields: {
+            FIELD_NAME: {
+              ...field,
+              args: Array.isArray(field.args)
+                ? _keyBy(field.args, 'name')
+                : field.args,
+            },
+          },
+        }),
+      ).replace('FIELD_NAME', `(meta-field) ${field.name}`);
+
+      const lines = printedType.split('\n');
+      return lines
+        .slice(1, lines.length - 1) // remove first and last line which is type we need field only
+        .map(line => line.trim())
+        .join('\n');
+    }),
+  };
+});
+
+export { SchemaMetaFieldDef, TypeMetaFieldDef, TypeNameMetaFieldDef };
+
 function printArg(arg, indentation = '') {
   return [
     `${indentation}${printDescription(arg.description)}`,