GraphQL Code Generator Plugin to define mock data factory.
npm install -D @mizdra/graphql-codegen-typescript-fabbrica @graphql-codegen/cli @graphql-codegen/typescript
npm install -S graphqlgraphql>= 16.0.0typescript>= 5.0.0--moduleResolution Bundler,--moduleResolution Node16or--moduleResolution NodeNextis required
You can try this library in the following playground.
First, you should configure the configuration file of GraphQL Code Generator as follows.
// codegen.ts
import { CodegenConfig } from '@graphql-codegen/cli';
const config: CodegenConfig = {
schema: './schema.graphql',
generates: {
'__generated__/types.ts': {
plugins: ['typescript'],
config: {
enumsAsTypes: true, // required
avoidOptionals: true, // required
// skipIsAbstractType: false, // If you use Relay, you should set this option to `false`
},
},
'./__generated__/fabbrica.ts': {
plugins: ['@mizdra/graphql-codegen-typescript-fabbrica'],
config: {
typesFile: './types', // required
// typesFile: './types.js' // If you use factories from Node.js and set `--moduleResolution` of `tsconfig.json` to `Node16` or `NodeNext`, you should add `.js` extension
},
},
},
};
export default config;# schema.graphql
type Book {
id: ID!
title: String!
author: Author!
}
type Author {
id: ID!
name: String!
books: [Book!]!
}Second, you should generate the code with the GraphQL Code Generator.
npx graphql-codegenThen, the utilities to define a factory are generated. You can define your preferred factory with it.
// src/app.ts
import { defineBookFactory, defineAuthorFactory, dynamic } from '../__generated__/fabbrica';
import { faker } from '@faker-js/faker';
const BookFactory = defineBookFactory({
defaultFields: {
__typename: 'Book',
id: dynamic(({ seq }) => `Book-${seq}`),
title: dynamic(() => faker.word.noun()),
author: undefined,
},
});
const AuthorFactory = defineAuthorFactory({
defaultFields: {
__typename: 'Author',
id: dynamic(({ seq }) => `Author-${seq}`),
name: dynamic(() => faker.person.firstName()),
books: undefined,
},
});The factory generates strictly typed mock data.
// simple
const book0 = await BookFactory.build();
expect(book0).toStrictEqual({
__typename: 'Book',
id: 'Book-0',
title: expect.any(String),
author: undefined,
});
expectTypeOf(book0).toEqualTypeOf<{
__typename: 'Book';
id: string;
title: string;
author: undefined;
}>();
// nested
const book1 = await BookFactory.build({
author: await AuthorFactory.build(),
});
expect(book1).toStrictEqual({
__typename: 'Book',
id: 'Book-1',
title: expect.any(String),
author: {
__typename: 'Author',
id: 'Author-0',
name: expect.any(String),
books: undefined,
},
});
expectTypeOf(book1).toEqualTypeOf<{
__typename: 'Book';
id: string;
title: string;
author: {
__typename: 'Author';
id: string;
name: string;
books: undefined;
};
}>();The library has several notable features. And many of them are inspired by FactoryBot.
The dynamic function allows you to define fields with a dynamic value.
import { dynamic } from '../__generated__/fabbrica';
const BookFactory = defineBookFactory({
defaultFields: {
id: dynamic(() => faker.datatype.uuid()),
title: 'Yuyushiki',
},
});
expect(await BookFactory.build()).toStrictEqual({
id: expect.any(String), // Randomly generated UUID
title: 'Yuyushiki',
});Sequences allow you to build sequentially numbered data.
const BookFactory = defineBookFactory({
defaultFields: {
id: dynamic(({ seq }) => `Book-${seq}`),
title: dynamic(async ({ seq }) => Promise.resolve(`Yuyushiki Vol.${seq}`)),
author: undefined,
},
});
expect(await BookFactory.build()).toStrictEqual({
id: 'Book-0',
title: 'Yuyushiki Vol.0',
author: undefined,
});
expect(await BookFactory.build()).toStrictEqual({
id: 'Book-1',
title: 'Yuyushiki Vol.1',
author: undefined,
});Fields can be based on the values of other fields using get function.
const UserFactory = defineUserFactory({
defaultFields: {
id: dynamic(({ seq }) => `User-${seq}`),
name: 'yukari',
email: dynamic(async ({ get }) => `${(await get('name')) ?? 'defaultName'}@yuyushiki.net`),
},
});
expect(await UserFactory.build()).toStrictEqual({
id: 'User-0',
name: 'yukari',
email: '[email protected]',
});
expect(await UserFactory.build({ name: 'yui' })).toStrictEqual({
id: 'User-1',
name: 'yui',
email: '[email protected]',
});You can build a list of mock data with the buildList method.
const BookFactory = defineBookFactory({
defaultFields: {
id: dynamic(({ seq }) => `Book-${seq}`),
title: dynamic(({ seq }) => `Yuyushiki Vol.${seq}`),
author: undefined,
},
});
expect(await BookFactory.buildList(3)).toStrictEqual([
{ id: 'Book-0', title: 'Yuyushiki Vol.0', author: undefined },
{ id: 'Book-1', title: 'Yuyushiki Vol.1', author: undefined },
{ id: 'Book-2', title: 'Yuyushiki Vol.2', author: undefined },
]);You can build a connection of mock data with the buildConnection method.
const BookFactory = defineBookFactory({
defaultFields: {
id: dynamic(({ seq }) => `Book-${seq}`),
},
});
expect(await BookFactory.buildConnection(3, { first: 2 })).toStrictEqual([
edges: [
{ cursor: "YXJyYXljb25uZWN0aW9uOjA=", node: { id: 'Book-0' } },
{ cursor: "YXJyYXljb25uZWN0aW9uOjE=", node: { id: 'Book-1' } },
],
pageInfo: {
startCursor: "YXJyYXljb25uZWN0aW9uOjA=",
endCursor: "YXJyYXljb25uZWN0aW9uOjE=",
hasPreviousPage: false,
hasNextPage: true,
},
]);You can build mock data of the relevant type in one shot.
const BookFactory = defineBookFactory({
defaultFields: {
id: dynamic(({ seq }) => `Book-${seq}`),
title: dynamic(({ seq }) => `Yuyushiki Vol.${seq}`),
author: undefined,
},
});
const AuthorFactory = defineAuthorFactory({
defaultFields: {
id: dynamic(({ seq }) => `Author-${seq}`),
name: 'Komata Mikami',
books: dynamic(async () => BookFactory.buildList(1)), // Build mock data of related types
},
});
expect(await AuthorFactory.build()).toStrictEqual({
id: 'Author-0',
name: 'Komata Mikami',
books: [{ id: 'Book-0', title: 'Yuyushiki Vol.0', author: undefined }],
});Transient fields are only available within the factory definition and are not included in the data being built. This allows more complex logic to be used inside factories.
import { defineAuthorFactory, dynamic } from '../__generated__/fabbrica';
import { Author } from '../__generated__/types';
const AuthorFactory = defineAuthorFactory.withTransientFields({
bookCount: 0,
})({
defaultFields: {
id: dynamic(({ seq }) => `Author-${seq}`),
name: 'Komata Mikami',
books: dynamic(async ({ get }) => {
const bookCount = (await get('bookCount')) ?? 0;
return BookFactory.buildList(bookCount);
}),
},
});
expect(await AuthorFactory.build({ bookCount: 3 })).toStrictEqual({
id: 'Author-0',
name: 'Komata Mikami',
books: [
{ id: 'Book-0', title: 'Yuyushiki Vol.0', author: undefined },
{ id: 'Book-1', title: 'Yuyushiki Vol.1', author: undefined },
{ id: 'Book-2', title: 'Yuyushiki Vol.2', author: undefined },
],
});You can add additional fields to the data being built. This is useful when you want to build a fake data for a query that contains aliases, such as:
query GetAuthorInfo {
author(id: '1') {
id
name
books {
id
title
}
popularBooks: books(popularOnly: true) {
id
title
}
}
}import { defineAuthorFactory, type OptionalAuthor, dynamic } from '../__generated__/fabbrica';
const AuthorFactory = defineAuthorFactory.withAdditionalFields<{ popularBooks: OptionalAuthor['books'] }>()({
defaultFields: {
id: dynamic(({ seq }) => `Author-${seq}`),
name: 'Komata Mikami',
// Generate a fake data for the `Author.books()` field
books: dynamic(() => BookFactory.buildList(3)),
// Generate a fake data for the `Author.books(popularOnly: true)` field
popularBooks: dynamic(() => BookFactory.buildList(1)),
},
});
expect(await AuthorFactory.build()).toStrictEqual({
id: 'Author-0',
name: 'Komata Mikami',
books: [
{ id: 'Book-0', title: 'Yuyushiki Vol.0' },
{ id: 'Book-1', title: 'Yuyushiki Vol.1' },
{ id: 'Book-2', title: 'Yuyushiki Vol.2' },
],
popularBooks: [{ id: 'Book-3', title: 'Yuyushiki Vol.3' }],
});Traits allow you to group the default values of fields and apply them to factories.
import I_SPACER from '../assets/spacer.gif';
import I_AVATAR from '../assets/dummy/avatar.png';
import I_BANNER from '../assets/dummy/banner.png';
const ImageFactory = defineImageFactory({
defaultFields: {
id: dynamic(({ seq }) => `Image-${seq}`),
url: I_SPACER.src,
width: I_SPACER.width,
height: I_SPACER.height,
},
traits: {
avatar: {
defaultFields: {
url: I_AVATAR.src,
width: I_AVATAR.width,
height: I_AVATAR.height,
},
},
banner: {
defaultFields: {
url: I_BANNER.src,
width: I_BANNER.width,
height: I_BANNER.height,
},
},
},
});
expect(await ImageFactory.build()).toStrictEqual({
id: 'Image-0',
url: I_SPACER.src,
width: I_SPACER.width,
height: I_SPACER.height,
});
expect(await ImageFactory.use('avatar').build()).toStrictEqual({
id: 'Image-1',
url: I_AVATAR.src,
width: I_AVATAR.width,
height: I_AVATAR.height,
});
expect(await ImageFactory.use('banner').build()).toStrictEqual({
id: 'Image-2',
url: I_BANNER.src,
width: I_BANNER.width,
height: I_BANNER.height,
});Several configs can be set in the GraphQL Code Generator configuration file.
type: string, required
Defines the file path containing all GraphQL types. This file can be generated with the typescript plugin.
If you use factories on Node.js and set --moduleResolution of tsconfig.json to Node16 or NodeNext, you should add .js extension to the file path. If you use factories on other runtimes, you should not add .js extension.
import { CodegenConfig } from '@graphql-codegen/cli';
const config: CodegenConfig = {
schema: './schema.graphql',
generates: {
'__generated__/types.ts': {
plugins: ['typescript'],
config: {
// ...
},
},
'./__generated__/fabbrica.ts': {
plugins: ['@mizdra/graphql-codegen-typescript-fabbrica'],
config: {
typesFile: './types', // required
// typesFile: './types.js' // If you use factories from Node.js and set `--moduleResolution` of `tsconfig.json` to `Node16` or `NodeNext`, you should add `.js` extension
},
},
},
};type: boolean, default: false
Does not add __typename to the fields that can be passed to factory.
import { CodegenConfig } from '@graphql-codegen/cli';
const config: CodegenConfig = {
schema: './schema.graphql',
generates: {
'__generated__/types.ts': {
plugins: ['typescript'],
config: {
// ...
},
},
'./__generated__/fabbrica.ts': {
plugins: ['@mizdra/graphql-codegen-typescript-fabbrica'],
config: {
// ...
skipTypename: true,
},
},
},
};
export default config;type: boolean, default: true
Does not add __is<AbstractType> to the fields that can be passed to factory. __is<AbstractType> is a field that relay-compiler automatically adds to the query12. It is recommended for Relay users to set this option to false.
import { CodegenConfig } from '@graphql-codegen/cli';
const config: CodegenConfig = {
schema: './schema.graphql',
generates: {
'__generated__/types.ts': {
plugins: ['typescript'],
config: {
// ...
},
},
'./__generated__/fabbrica.ts': {
plugins: ['@mizdra/graphql-codegen-typescript-fabbrica'],
config: {
// ...
skipIsAbstractType: false,
},
},
},
};
export default config;type: boolean, default: false
Make it mandatory to pass all fields to defaultFields. This is useful to force the defaultFields to be updated when new fields are added to the schema.
import { CodegenConfig } from '@graphql-codegen/cli';
const config: CodegenConfig = {
schema: './schema.graphql',
generates: {
'__generated__/types.ts': {
plugins: ['typescript'],
config: {
// ...
},
},
'./__generated__/fabbrica.ts': {
plugins: ['@mizdra/graphql-codegen-typescript-fabbrica'],
config: {
// ...
nonOptionalDefaultFields: true,
},
},
},
};
export default config;type: NamingConvention, default: change-case-all#pascalCase
Allow you to override the naming convention of the output.
This option is compatible with the one for typescript plugin. If you specify it for the typescript plugin, you must set the same value for graphql-codegen-typescript-fabbrica.
import { CodegenConfig } from '@graphql-codegen/cli';
const config: CodegenConfig = {
schema: './schema.graphql',
config: {
namingConvention: 'change-case-all#lowerCase',
},
generates: {
'__generated__/types.ts': {
plugins: ['typescript'],
// ...
},
'./__generated__/fabbrica.ts': {
plugins: ['@mizdra/graphql-codegen-typescript-fabbrica'],
// ...
},
},
};
export default config;type: string, default: ''
Prefixes all the generated types.
This option is compatible with the one for typescript plugin. If you specify it for the typescript plugin, you must set the same value for graphql-codegen-typescript-fabbrica.
import { CodegenConfig } from '@graphql-codegen/cli';
const config: CodegenConfig = {
schema: './schema.graphql',
config: {
typesPrefix: 'I',
},
generates: {
'__generated__/types.ts': {
plugins: ['typescript'],
// ...
},
'./__generated__/fabbrica.ts': {
plugins: ['@mizdra/graphql-codegen-typescript-fabbrica'],
// ...
},
},
};
export default config;type: string, default: ''
Suffixes all the generated types.
This option is compatible with the one for typescript plugin. If you specify it for the typescript plugin, you must set the same value for graphql-codegen-typescript-fabbrica.
Creating a circular type with Associations may cause compile errors.
const BookFactory = defineBookFactory({
defaultFields: {
id: dynamic(({ seq }) => `Book-${seq}`),
title: dynamic(({ seq }) => `ゆゆ式 ${seq}巻`),
author: dynamic(({ seq }) => AuthorFactory.build()),
},
});
const AuthorFactory = defineAuthorFactory({
defaultFields: {
id: dynamic(({ seq }) => `Author-${seq}`),
name: dynamic(({ seq }) => `${seq}上小又`),
books: dynamic(({ seq }) => BookFactory.buildList()),
},
});$ npx tsc --noEmit
example.ts:1:7 - error TS7022: 'BookFactory' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.
1 const BookFactory = defineBookFactory({
~~~~~~~~~~~
example.ts:8:7 - error TS7022: 'AuthorFactory' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.
8 const AuthorFactory = defineAuthorFactory({
~~~~~~~~~~~~~This error is due to the type of each field being cycled, making the type undecidable. To avoid this, you can pass undefined to any field.
const BookFactory = defineBookFactory({
defaultFields: {
id: dynamic(({ seq }) => `Book-${seq}`),
title: dynamic(({ seq }) => `ゆゆ式 ${seq}巻`),
author: dynamic(({ seq }) => AuthorFactory.build()),
},
});
const AuthorFactory = defineAuthorFactory({
defaultFields: {
id: dynamic(({ seq }) => `Author-${seq}`),
name: dynamic(({ seq }) => `${seq}上小又`),
// Pass `undefined` to avoid type being undecidable.
books: undefined,
},
});error TS2307: Cannot find module '@mizdra/graphql-codegen-typescript-fabbrica/helper' or its corresponding type declarations.
Incorrect values for the moduleResolution option in tsconfig.json cause compile errors.
{
"compilerOptions": {
"moduleResolution": "node" // incorrect
}
}$ npx tsc --noEmit
__generated__/1-basic/fabbrica.ts:7:8 - error TS2307: Cannot find module '@mizdra/graphql-codegen-typescript-fabbrica/helper' or its corresponding type declarations.
7 } from '@mizdra/graphql-codegen-typescript-fabbrica/helper';
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~To resolve this error, set the value of moduleResolution to Bundler, Node16 or NodeNext.
{
"compilerOptions": {
"moduleResolution": "Bundler" // ok
}
}This library is licensed under the MIT license.
The copyright contains two names. The first is @mizdra, author of graphql-codegen-typescript-fabbrica. The second is @Quramy, author of prisma-fabbrica.
The name of the author of prisma-fabbrica is written because graphql-codegen-typescript-fabbrica reuses some of prisma-fabbrica's code.