-
Notifications
You must be signed in to change notification settings - Fork 2k
/
extendSchema.js
374 lines (337 loc) · 12.1 KB
/
extendSchema.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
*/
import invariant from '../jsutils/invariant';
import keyMap from '../jsutils/keyMap';
import { ASTDefinitionBuilder } from './buildASTSchema';
import { GraphQLError } from '../error/GraphQLError';
import { isSchema, GraphQLSchema } from '../type/schema';
import {
isObjectType,
isInterfaceType,
isUnionType,
isListType,
isNonNullType,
GraphQLObjectType,
GraphQLInterfaceType,
GraphQLUnionType,
} from '../type/definition';
import { GraphQLList, GraphQLNonNull } from '../type/wrappers';
import { GraphQLDirective } from '../type/directives';
import { Kind } from '../language/kinds';
import type { GraphQLType, GraphQLNamedType } from '../type/definition';
import type { DocumentNode, DirectiveDefinitionNode } from '../language/ast';
type Options = {|
/**
* When extending a schema with a known valid extension, it might be safe to
* assume the schema is valid. Set to true to assume the produced schema
* is valid.
*
* Default: false
*/
assumeValid?: boolean,
/**
* Descriptions are defined as preceding string literals, however an older
* experimental version of the SDL supported preceding comments as
* descriptions. Set to true to enable this deprecated behavior.
*
* Default: false
*/
commentDescriptions?: boolean,
|};
/**
* Produces a new schema given an existing schema and a document which may
* contain GraphQL type extensions and definitions. The original schema will
* remain unaltered.
*
* Because a schema represents a graph of references, a schema cannot be
* extended without effectively making an entire copy. We do not know until it's
* too late if subgraphs remain unchanged.
*
* This algorithm copies the provided schema, applying extensions while
* producing the copy. The original schema remains unaltered.
*
* Accepts options as a third argument:
*
* - commentDescriptions:
* Provide true to use preceding comments as the description.
*
*/
export function extendSchema(
schema: GraphQLSchema,
documentAST: DocumentNode,
options?: Options,
): GraphQLSchema {
invariant(isSchema(schema), 'Must provide valid GraphQLSchema');
invariant(
documentAST && documentAST.kind === Kind.DOCUMENT,
'Must provide valid Document AST',
);
// Collect the type definitions and extensions found in the document.
const typeDefinitionMap = Object.create(null);
const typeExtensionsMap = Object.create(null);
// New directives and types are separate because a directives and types can
// have the same name. For example, a type named "skip".
const directiveDefinitions: Array<DirectiveDefinitionNode> = [];
for (let i = 0; i < documentAST.definitions.length; i++) {
const def = documentAST.definitions[i];
switch (def.kind) {
case Kind.OBJECT_TYPE_DEFINITION:
case Kind.INTERFACE_TYPE_DEFINITION:
case Kind.ENUM_TYPE_DEFINITION:
case Kind.UNION_TYPE_DEFINITION:
case Kind.SCALAR_TYPE_DEFINITION:
case Kind.INPUT_OBJECT_TYPE_DEFINITION:
// Sanity check that none of the defined types conflict with the
// schema's existing types.
const typeName = def.name.value;
if (schema.getType(typeName)) {
throw new GraphQLError(
`Type "${typeName}" already exists in the schema. It cannot also ` +
'be defined in this type definition.',
[def],
);
}
typeDefinitionMap[typeName] = def;
break;
case Kind.OBJECT_TYPE_EXTENSION:
// Sanity check that this type extension exists within the
// schema's existing types.
const extendedTypeName = def.name.value;
const existingType = schema.getType(extendedTypeName);
if (!existingType) {
throw new GraphQLError(
`Cannot extend type "${extendedTypeName}" because it does not ` +
'exist in the existing schema.',
[def],
);
}
if (!isObjectType(existingType)) {
throw new GraphQLError(
`Cannot extend non-object type "${extendedTypeName}".`,
[def],
);
}
let extensions = typeExtensionsMap[extendedTypeName];
if (extensions) {
extensions.push(def);
} else {
extensions = [def];
}
typeExtensionsMap[extendedTypeName] = extensions;
break;
case Kind.DIRECTIVE_DEFINITION:
const directiveName = def.name.value;
const existingDirective = schema.getDirective(directiveName);
if (existingDirective) {
throw new GraphQLError(
`Directive "${directiveName}" already exists in the schema. It ` +
'cannot be redefined.',
[def],
);
}
directiveDefinitions.push(def);
break;
case Kind.SCALAR_TYPE_EXTENSION:
case Kind.INTERFACE_TYPE_EXTENSION:
case Kind.UNION_TYPE_EXTENSION:
case Kind.ENUM_TYPE_EXTENSION:
case Kind.INPUT_OBJECT_TYPE_EXTENSION:
throw new Error(
`The ${def.kind} kind is not yet supported by extendSchema().`,
);
}
}
// If this document contains no new types, extensions, or directives then
// return the same unmodified GraphQLSchema instance.
if (
Object.keys(typeExtensionsMap).length === 0 &&
Object.keys(typeDefinitionMap).length === 0 &&
directiveDefinitions.length === 0
) {
return schema;
}
const definitionBuilder = new ASTDefinitionBuilder(
typeDefinitionMap,
options,
(typeName, node) => {
const existingType = schema.getType(typeName);
if (existingType) {
return extendType(existingType);
}
if (node) {
throw new GraphQLError(
`Unknown type: "${typeName}". Ensure that this type exists ` +
'either in the original schema, or is added in a type definition.',
[node],
);
}
throw GraphQLError('Missing type from schema');
},
);
// Get the root Query, Mutation, and Subscription object types.
// Note: While this could make early assertions to get the correctly
// typed values below, that would throw immediately while type system
// validation with validateSchema() will produce more actionable results.
const existingQueryType = schema.getQueryType();
const queryType = existingQueryType
? (definitionBuilder.buildType(existingQueryType.name): any)
: null;
const existingMutationType = schema.getMutationType();
const mutationType = existingMutationType
? (definitionBuilder.buildType(existingMutationType.name): any)
: null;
const existingSubscriptionType = schema.getSubscriptionType();
const subscriptionType = existingSubscriptionType
? (definitionBuilder.buildType(existingSubscriptionType.name): any)
: null;
// Iterate through all types, getting the type definition for each, ensuring
// that any type not directly referenced by a field will get created.
const typeMap = schema.getTypeMap();
const types = Object.keys(typeMap).map(typeName =>
definitionBuilder.buildType(typeName),
);
// Do the same with new types, appending to the list of defined types.
Object.keys(typeDefinitionMap).forEach(typeName => {
types.push(definitionBuilder.buildType(typeName));
});
// Then produce and return a Schema with these types.
return new GraphQLSchema({
query: queryType,
mutation: mutationType,
subscription: subscriptionType,
types,
directives: getMergedDirectives(),
astNode: schema.astNode,
});
// Below are functions used for producing this schema that have closed over
// this scope and have access to the schema, cache, and newly defined types.
function getMergedDirectives(): Array<GraphQLDirective> {
const existingDirectives = schema.getDirectives();
invariant(existingDirectives, 'schema must have default directives');
const newDirectives = directiveDefinitions.map(directiveNode =>
definitionBuilder.buildDirective(directiveNode),
);
return existingDirectives.concat(newDirectives);
}
function getTypeFromDef<T: GraphQLNamedType>(typeDef: T): T {
const type = definitionBuilder.buildType(typeDef.name);
return (type: any);
}
// Given a type's introspection result, construct the correct
// GraphQLType instance.
function extendType(type: GraphQLNamedType): GraphQLNamedType {
if (isObjectType(type)) {
return extendObjectType(type);
}
if (isInterfaceType(type)) {
return extendInterfaceType(type);
}
if (isUnionType(type)) {
return extendUnionType(type);
}
return type;
}
function extendObjectType(type: GraphQLObjectType): GraphQLObjectType {
const name = type.name;
const extensionASTNodes = typeExtensionsMap[name]
? type.extensionASTNodes
? type.extensionASTNodes.concat(typeExtensionsMap[name])
: typeExtensionsMap[name]
: type.extensionASTNodes;
return new GraphQLObjectType({
name,
description: type.description,
interfaces: () => extendImplementedInterfaces(type),
fields: () => extendFieldMap(type),
astNode: type.astNode,
extensionASTNodes,
isTypeOf: type.isTypeOf,
});
}
function extendInterfaceType(
type: GraphQLInterfaceType,
): GraphQLInterfaceType {
return new GraphQLInterfaceType({
name: type.name,
description: type.description,
fields: () => extendFieldMap(type),
astNode: type.astNode,
resolveType: type.resolveType,
});
}
function extendUnionType(type: GraphQLUnionType): GraphQLUnionType {
return new GraphQLUnionType({
name: type.name,
description: type.description,
types: type.getTypes().map(getTypeFromDef),
astNode: type.astNode,
resolveType: type.resolveType,
});
}
function extendImplementedInterfaces(
type: GraphQLObjectType,
): Array<GraphQLInterfaceType> {
const interfaces = type.getInterfaces().map(getTypeFromDef);
// If there are any extensions to the interfaces, apply those here.
const extensions = typeExtensionsMap[type.name];
if (extensions) {
extensions.forEach(extension => {
extension.interfaces.forEach(namedType => {
// Note: While this could make early assertions to get the correctly
// typed values, that would throw immediately while type system
// validation with validateSchema() will produce more actionable results.
interfaces.push((definitionBuilder.buildType(namedType): any));
});
});
}
return interfaces;
}
function extendFieldMap(type: GraphQLObjectType | GraphQLInterfaceType) {
const newFieldMap = Object.create(null);
const oldFieldMap = type.getFields();
Object.keys(oldFieldMap).forEach(fieldName => {
const field = oldFieldMap[fieldName];
newFieldMap[fieldName] = {
description: field.description,
deprecationReason: field.deprecationReason,
type: extendFieldType(field.type),
args: keyMap(field.args, arg => arg.name),
astNode: field.astNode,
resolve: field.resolve,
};
});
// If there are any extensions to the fields, apply those here.
const extensions = typeExtensionsMap[type.name];
if (extensions) {
extensions.forEach(extension => {
extension.fields.forEach(field => {
const fieldName = field.name.value;
if (oldFieldMap[fieldName]) {
throw new GraphQLError(
`Field "${type.name}.${fieldName}" already exists in the ` +
'schema. It cannot also be defined in this type extension.',
[field],
);
}
newFieldMap[fieldName] = definitionBuilder.buildField(field);
});
});
}
return newFieldMap;
}
function extendFieldType<T: GraphQLType>(typeDef: T): T {
if (isListType(typeDef)) {
return (GraphQLList(extendFieldType(typeDef.ofType)): any);
}
if (isNonNullType(typeDef)) {
return (GraphQLNonNull(extendFieldType(typeDef.ofType)): any);
}
return getTypeFromDef(typeDef);
}
}