ardeois
graphql-codegen-typescript-mock-data
Description
GraphQL Codegen Plugin for building mock data based on the schema.
Installation
yarn add -D graphql-codegen-typescript-mock-data
Configuration
typesFile (string, defaultValue: null)
Defines the file path containing all GraphQL types. This file can also be generated through graphql-codegen
useTypeImports(boolean, defaultValue: false)
Will use import type {} rather than import {} when importing only types. This gives compatibility with TypeScript's "importsNotUsedAsValues": "error" option
addTypename (boolean, defaultValue: false)
Adds __typename property to mock data
enumsAsTypes (boolean, defaultValue: false)
Changes enums to TypeScript string union types
includedTypes (string[], defaultValue: undefined)
Specifies an array of types to include in the mock generation. When provided, only the types listed in this array will have mock data generated.
Example:
plugins:
- typescript-mock-data:
includedTypes:
- User
- AvatarexcludedTypes (string[], defaultValue: undefined)
Specifies an array of types to exclude in the mock generation. When provided, the types listed in this array will not have mock data generated.
Example:
plugins:
- typescript-mock-data:
excludedTypes:
- User
- AvatarterminateCircularRelationships (boolean | 'immediate', defaultValue: false)
When enabled, prevents circular relationships from triggering infinite recursion. After the first resolution of a specific type in a particular call stack, subsequent resolutions will return an empty object cast to the correct type.
When enabled with immediate, it will only resolve the relationship once, independently of the call stack. Use this option if you're experiencing out of memory errors while generating mocks.
prefix (string, defaultValue: a for consonants & an for vowels)
The prefix to add to the mock function name. Cannot be empty since it will clash with the associated
typescript definition from @graphql-codegen/typescript
listElementCount (number, defaultValue: 1)
How many elements should be generated for lists. For example, with listElementCount: 3 a schema field names: [String!]! would generate 3 names in each mock.
enumValues (string, defaultValue: change-case-all#pascalCase)
Changes the case of the enums. The format of the converter must be a valid module#method. You can also use keep to
keep all GraphQL names as-is. Available case functions in change-case-all are camelCase, capitalCase, constantCase,
dotCase, headerCase, noCase, paramCase, pascalCase, pathCase, sentenceCase, snakeCase, lowerCase,
localeLowerCase, lowerCaseFirst, spongeCase, titleCase, upperCase, localeUpperCase and upperCaseFirst
See more
typeNames (string, defaultValue: change-case-all#pascalCase)
Changes the case of types. The format of the converter must be a valid module#method. You can also use keep to
keep all GraphQL names as-is. Available case functions in change-case-all are camelCase, capitalCase, constantCase,
dotCase, headerCase, noCase, paramCase, pascalCase, pathCase, sentenceCase, snakeCase, lowerCase,
localeLowerCase, lowerCaseFirst, spongeCase, titleCase, upperCase, localeUpperCase and upperCaseFirst
See more
scalars ({ [Scalar: string]: GeneratorOptions | InputOutputGeneratorOptions }, defaultValue: undefined)
Allows you to define mappings for your custom scalars. Allows you to map any GraphQL Scalar to a casual embedded generator (string or function key) with optional arguments, or a or faker generator with optional arguments
For detailed configuration options, see GeneratorOptions documentation.
Examples using casual
plugins:
- typescript-mock-data:
scalars:
Date: date # gets translated to casual.date()With arguments
plugins:
- typescript-mock-data:
scalars:
Date: # gets translated to casual.date('YYYY-MM-DD')
generator: date
arguments: 'YYYY-MM-DD'Examples using faker
plugins:
- typescript-mock-data:
scalars:
Date: date.past # gets translated to faker.date.past()With arguments
plugins:
- typescript-mock-data:
scalars:
Date: # gets translated to faker.date.past(10)
generator: date.past
arguments: 10Custom value generator
plugins:
- add: "import { arrayBufferGenerator } from '../generators';"
- typescript-mock-data:
scalars:
ArrayBuffer: arrayBufferGenerator()typesPrefix (string, defaultValue: '')
Useful if you have globally exported types under a certain namespace. e.g If the types file is something like this
declare namespace Api {
type User {
...
}
}Setting the typesPrefix to Api. will create the following mock data
export const aUser = (overrides?: Partial<Api.User>): Api.User => {enumsPrefix (string, defaultValue: '')
Similar to typesPrefix, but for enum types
declare namespace Api {
enum Status {
...
}
}Setting the enumsPrefix to Api. will create the following mock data
export const aUser = (overrides?: Partial<User>): User => {
status: overrides && overrides.hasOwnProperty('status') ? overrides.status! : Api.Status.Online,
}typeNamesMapping ({ [typeName: string]: string }, defaultValue: {})
Allows you to define mappings to rename the types. This is useful when you want to override the generated type name. For example, if you have a type called User and you want to rename it to RenamedUser you can do the following:
plugins:
- typescript-mock-data:
typesFile: '../generated-types.ts'
typeNamesMapping:
User: RenamedUserThis will generate the following mock function:
export const aUser = (overrides?: Partial<RenamedUser>): RenamedUser => {Note: It is not possible to rename your enums using this option.
transformUnderscore (boolean, defaultValue: true)
When disabled, underscores will be retained for type names when the case is changed. It has no effect if typeNames is set to keep.
dynamicValues (boolean, defaultValue: false)
When enabled, values will be generated dynamically when the mock function is called rather than statically when the mock function is generated. The values are generated consistently from a casual seed that can be manually configured using the generated seedMocks(seed: number) function, as shown in this test.
useImplementingTypes (boolean, defaultValue: false)
When enabled, it will support the useImplementingTypes GraphQL codegen configuration.
- When a GraphQL interface is used for a field, this flag will use the implementing types, instead of the interface itself.
defaultNullableToNull (boolean, defaultValue: false)
When enabled, it will set all nullable fields to null per default instead of generating a value.
fieldGeneration ({ [typeName: string]: { [fieldName: string]: GeneratorOptions } }, defaultValue: undefined)
This setting allows you to add specific generation to a field for a given type. For example if you have a type called User and a field called birthDate you can override any generated value there as follows:
plugins:
- typescript-mock-data:
scalars:
Date: date.future
fieldGeneration:
User:
birthDate: date.pastNote that even if birthDate is a scalar of Date type, its value will still be overridden.
If you want to use a specific generator for all fields of a given name, you can declare it under a property called _all:
plugins:
- typescript-mock-data:
scalars:
Date: date.future
fieldGeneration:
_all:
email: internet.email
AdminUser:
email: 'admin@email.com'In the above example all resolvers with the name email will use the internet.email generator. However since we specified a specific email for AdminUser that will take precedence over the _all generated value.
For detailed configuration options, see GeneratorOptions documentation.
generateLibrary ('casual' | 'faker', defaultValue: 'faker')
Select a library to generate mock values. The default is faker, Other options include casual casual is not maintained and will be remove in future major versions. faker is useful when you want to use a mock function with the dynamicValues option enabled in the browser.
GeneratorOptions type
This type is used in scalars and fieldGeneration options.
Examples using faker
With arguments
plugins:
- typescript-mock-data:
scalars:
Date: # gets translated to faker.date.past(10)
generator: date.past
arguments: 10With multiple arguments
plugins:
- typescript-mock-data:
scalars:
Description: # gets translated to faker.lorem.paragraphs(3, '\n')
generator: lorem.paragraphs
arguments:
- 3
- '\n'Shorthand if you don't have arguments
plugins:
- typescript-mock-data:
scalars:
Date: date.past # gets translated to faker.date.past()With extra function call
fieldName: # gets translated to faker.date.past().toLocaleDateString()
generator: date.past
extra:
function: toLocaleDateStringWith extra function call arguments
fieldName: # gets translated to faker.date.past().toLocaleDateString('en_GB)
generator: date.past
extra:
function: toLocaleDateString
arguments: 'en_GB'Custom value generator
# gets translated as is
fieldName: arrayBufferGenerator()Examples using casual (deprecated)
Shorthand if you don't have arguments
fieldName: date # gets translated to casual.date()With arguments
fieldName: # gets translated to casual.date('YYYY-MM-DD')
generator: date
arguments: 'YYYY-MM-DD'With multiple arguments
fieldName: # gets translated to casual.integer(-100, 100)
generator: integer
arguments:
- -100
- 100With extra function call
fieldName: # gets translated to casual.integer.toFixed()
generator: integer
extra:
function: toFixedWith extra function call arguments
fieldName: # gets translated to casual.integer.toFixed(3)
generator: integer
extra:
function: toFixed
arguments: 3InputOutputGeneratorOptions type
This type is used in the scalars option. It allows you to specify different GeneratorOptions for input and output types for
your scalars, in the same way the typescript-operations plugin does.
So, using the first example of the previous section, you can specify a string for your input and a Date for your output:
plugins:
- typescript-mock-data:
scalars:
Date:
input: date.weekday # Date fields in input objects will be mocked as strings
output:
generator: date.past # Date fields in other GraphQL types will be mocked as JS Dates
arguments: 10Examples of usage
codegen.yml
overwrite: true
schema: schema.graphql
generates:
src/generated-types.ts:
plugins:
- 'typescript'
src/mocks/generated-mocks.ts:
plugins:
- typescript-mock-data:
typesFile: '../generated-types.ts'
enumValues: upper-case#upperCase
typeNames: keep
scalars:
AWSTimestamp: number.int # gets translated to faker.number.int()With eslint-disable rule
codegen.yml
overwrite: true
schema: schema.graphql
generates:
src/generated-types.ts:
plugins:
- 'typescript'
src/mocks/generated-mocks.ts:
plugins:
- add:
content: '/* eslint-disable @typescript-eslint/no-use-before-define,@typescript-eslint/no-unused-vars,no-prototype-builtins */'
- typescript-mock-data:
typesFile: '../generated-types.ts'
enumValues: upper-case#upperCase
typeNames: keep
scalars:
AWSTimestamp: number.int # gets translated to faker.number.int()Example of generated code
Given the following schema:
scalar AWSTimestamp
type Avatar {
id: ID!
url: String!
}
type User {
id: ID!
login: String!
avatar: Avatar
status: Status!
updatedAt: AWSTimestamp
}
type Query {
user: User!
}
input UpdateUserInput {
id: ID!
login: String
avatar: Avatar
}
enum Status {
ONLINE
OFFLINE
}
type Mutation {
updateUser(user: UpdateUserInput): User
}The code generated will look like:
export const anAvatar = (overrides?: Partial<Avatar>): Avatar => {
return {
id: overrides && overrides.hasOwnProperty('id') ? overrides.id! : '0550ff93-dd31-49b4-8c38-ff1cb68bdc38',
url: overrides && overrides.hasOwnProperty('url') ? overrides.url! : 'aliquid',
};
};
export const anUpdateUserInput = (overrides?: Partial<UpdateUserInput>): UpdateUserInput => {
return {
id: overrides && overrides.hasOwnProperty('id') ? overrides.id! : '1d6a9360-c92b-4660-8e5f-04155047bddc',
login: overrides && overrides.hasOwnProperty('login') ? overrides.login! : 'qui',
avatar: overrides && overrides.hasOwnProperty('avatar') ? overrides.avatar! : anAvatar(),
};
};
export const aUser = (overrides?: Partial<User>): User => {
return {
id: overrides && overrides.hasOwnProperty('id') ? overrides.id! : 'a5756f00-41a6-422a-8a7d-d13ee6a63750',
login: overrides && overrides.hasOwnProperty('login') ? overrides.login! : 'libero',
avatar: overrides && overrides.hasOwnProperty('avatar') ? overrides.avatar! : anAvatar(),
status: overrides && overrides.hasOwnProperty('status') ? overrides.status! : Status.Online,
updatedAt: overrides && overrides.hasOwnProperty('updatedAt') ? overrides.updatedAt! : 1458071232,
};
};Usage in tests
Those helper functions can be used in our unit tests:
const user = aUser({ login: 'johndoe' });
// will create a user object with `login` property overridden to `johndoe`Dealing with Timezone
If some properties use generated dates, the result could different depending on the timezone of your machine.
To force a timezone, you can set environment variable TZ:
TZ=UTC graphql-codegenThis will force the timezone to UTC, whatever the timezone of your machine or CI
Contributing
Feel free to open issues and pull requests. We always welcome support from the community.
To run this project locally:
- Use Node >= 18
- Make sure that you have the latest Yarn version (https://yarnpkg.com/lang/en/docs/install/)
- Clone this repo using
git clone - Run
yarn - Run
yarn buildto build the package - Run
yarn testto make sure everything works
License
MIT