Flow Resolvers
yarn add @graphql-codegen/flow-resolverspnpm add @graphql-codegen/flow-resolversnpm install @graphql-codegen/flow-resolversThis plugin generates resolvers signature based on your GraphQLSchema.
It generates types for your entire schema: types, input types, enum, interface, scalar and union.
This plugin requires you to use @graphql-codegen/flow as well, because it depends on its types.
Config API Reference#
addUnderscoreToArgsType
type: boolean
Adds _ to generated Args types in order to avoid duplicate identifiers.
Usage Examples#
config:
addUnderscoreToArgsType: true
contextType
type: string
Use this configuration to set a custom type for your context, and it will
affect all the resolvers, without the need to override it using generics each time.
If you wish to use an external type and import it from another file, you can use add plugin
and add the required import statement, or you can use a module#type syntax.
Usage Examples#
Custom Context Type#
plugins
config:
contextType: MyContext
Custom Context Type#
plugins
config:
contextType: ./my-types#MyContext
fieldContextTypes
type: Array_1
Use this to set a custom type for a specific field context.
It will only affect the targeted resolvers.
You can either use Field.Path#ContextTypeName or Field.Path#ExternalFileName#ContextTypeName
Usage Examples#
Custom Field Context Types#
plugins
config:
fieldContextTypes:
- MyType.foo#CustomContextType
- MyType.bar#./my-file#ContextTypeOne
directiveContextTypes
type: Array_1
Use this configuration to set a custom type for the rootValue, and it will
affect resolvers of all root types (Query, Mutation and Subscription), without the need to override it using generics each time.
If you wish to use an external type and import it from another file, you can use add plugin
and add the required import statement, or you can use both module#type or module#namespace#type syntax.
Usage Examples#
Custom RootValue Type#
plugins
config:
rootValueType: MyRootValue
Custom RootValue Type#
plugins
config:
rootValueType: ./my-types#MyRootValue
rootValueType
type: string
Use this to set a custom type for a specific field context decorated by a directive.
It will only affect the targeted resolvers.
You can either use Field.Path#ContextTypeName or Field.Path#ExternalFileName#ContextTypeName
ContextTypeName should by a generic Type that take the context or field context type as only type parameter.
Usage Examples#
Directive Context Extender#
plugins
config:
directiveContextTypes:
- myCustomDirectiveName#./my-file#CustomContextExtender
mapperTypeSuffix
type: string
Adds a suffix to the imported names to prevent name clashes.
Usage Examples#
plugins
config:
mapperTypeSuffix: Model
mappers
type: object
Replaces a GraphQL type usage with a custom type, allowing you to return custom object from
your resolvers.
You can use both module#type and module#namespace#type syntax.
Usage Examples#
Custom Context Type#
plugins
config:
mappers:
User: ./my-models#UserDbObject
Book: ./my-models#Collections#Book
defaultMapper
type: string
Allow you to set the default mapper when it's not being override by mappers or generics.
You can specify a type name, or specify a string in module#type or module#namespace#type format.
The default value of mappers is the TypeScript type generated by typescript package.
Usage Examples#
Replace with any#
plugins
config:
defaultMapper: any
Custom Base Object#
plugins
config:
defaultMapper: ./my-file#BaseObject
Wrap default types with Partial#
You can also specify a custom wrapper for the original type, without overriding the original generated types, use {T} to specify the identifier. (for flow, use $Shape<{T}>)
plugins
config:
defaultMapper: Partial<{T}>
Allow deep partial with utility-types#
plugins
plugins:
- 'typescript'
- 'typescript-resolvers'
- add:
content: "import { DeepPartial } from 'utility-types';"
config:
defaultMapper: DeepPartial<{T}>
avoidOptionals
type: AvoidOptionalsConfig | boolean
default: false
This will cause the generator to avoid using optionals (?),
so all field resolvers must be implemented in order to avoid compilation errors.
Usage Examples#
Override all definition types#
generates:
path/to/file.ts:
plugins:
- typescript
- typescript-resolvers
config:
avoidOptionals: true
Override only specific definition types#
generates:
path/to/file.ts:
plugins:
- typescript
config:
avoidOptionals:
field: true
inputValue: true
object: true
defaultValue: true
showUnusedMappers
type: boolean
default: true
Warns about unused mappers.
Usage Examples#
generates:
path/to/file.ts:
plugins:
- typescript
- typescript-resolvers
config:
showUnusedMappers: true
enumValues
type: EnumValuesMap
Overrides the default value of enum values declared in your GraphQL schema, supported
in this plugin because of the need for integration with typescript package.
See documentation under typescript plugin for more information and examples.
resolverTypeWrapperSignature
type: string
default: Promise<T> | T
Allow you to override resolverTypeWrapper definition.
federation
type: boolean
default: false
Supports Apollo Federation
enumPrefix
type: boolean
default: true
Allow you to disable prefixing for generated enums, works in combination with typesPrefix.
Usage Examples#
Disable enum prefixes#
config:
typesPrefix: I
enumPrefix: false
optionalResolveType
type: boolean
default: false
Sets the __resolveType field as optional field.
immutableTypes
type: boolean
default: false
Generates immutable types by adding readonly to properties and uses ReadonlyArray.
namespacedImportName
type: string
default: ''
Prefixes all GraphQL related generated types with that value, as namespaces import. You can use this feature to allow separation of plugins to different files.
resolverTypeSuffix
type: string
default: Resolvers
Suffix we add to each generated type resolver.
allResolversTypeName
type: string
default: Resolvers
The type name to use when exporting all resolvers signature as unified type.
internalResolversPrefix
type: string
default: '__'
Defines the prefix value used for __resolveType and __isTypeOf resolvers.
If you are using mercurius-js, please set this field to empty string for better compatibility.
onlyResolveTypeForInterfaces
type: boolean
default: false
Turning this flag to true will generate resolver signature that has only resolveType for interfaces, forcing developers to write inherited type resolvers in the type itself.
strictScalars
type: boolean
default: false
Makes scalars strict.
If scalars are found in the schema that are not defined in scalars
an error will be thrown during codegen.
Usage Examples#
config:
strictScalars: true
defaultScalarType
type: string
default: any
Allows you to override the type that unknown scalars will have.
Usage Examples#
config:
defaultScalarType: unknown
scalars
type: ScalarsMap
Extends or overrides the built-in scalars and custom GraphQL scalars to a custom type.
namingConvention
type: NamingConvention
default: change-case-all#pascalCase
Allow you to override the naming convention of the output.
You can either override all namings, or specify an object with specific custom naming convention per output.
The format of the converter must be a valid module#method.
Allowed values for specific output are: typeNames, enumValues.
You can also use "keep" to keep all GraphQL names as-is.
Additionally, you can set transformUnderscore to true if you want to override the default behavior,
which is to preserve underscores.
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
typesPrefix
type: string
default: (empty)
Prefixes all the generated types.
Usage Examples#
config:
typesPrefix: I
typesSuffix
type: string
default: (empty)
Suffixes all the generated types.
Usage Examples#
config:
typesSuffix: I
skipTypename
type: boolean
default: false
Does not add __typename to the generated types, unless it was specified in the selection set.
Usage Examples#
config:
skipTypename: true
nonOptionalTypename
type: boolean
default: false
Automatically adds __typename field to the generated types, even when they are not specified
in the selection set, and makes it non-optional
Usage Examples#
config:
nonOptionalTypename: true
useTypeImports
type: boolean
default: false
Will use import type {} rather than import {} when importing only types. This gives
compatibility with TypeScript's "importsNotUsedAsValues": "error" option
dedupeFragments
type: boolean
default: false
Removes fragment duplicates for reducing data transfer. It is done by removing sub-fragments imports from fragment definition Instead - all of them are imported to the Operation node.
inlineFragmentTypes
type: InlineFragmentTypeOptions
default: inline
Whether fragment types should be inlined into other operations. "inline" is the default behavior and will perform deep inlining fragment types within operation type definitions. "combine" is the previous behavior that uses fragment type references without inlining the types (and might cause issues with deeply nested fragment that uses list types).
Usage Example#
Quick Start with flow-resolvers
You can find a blog post we wrote about using and customizing this plugin here, it refers to typescript-resolvers but everything there is relevant to flow-resolvers as well.
Enum Resolvers#
Apollo-Server and schemas built with graphql-tools supports creating resolvers for GraphQL enums.
This is helpful because you can have internal values that are different from the public enum values, and you can use the internal values in your resolvers.
Codegen allows you to specify either mappers or enumValues to map enums in your resolvers, and if you are using it for enums, you'll get a resolver signature for the enum resolvers as well.
Usage Example#
With the following schema:
type Query {
favoriteColor: Color!
}
enum Color {
RED
BLUE
}
schema: schema.graphql
generates:
./resolvers-types.js:
config:
enumValues:
Color: ./enums#ColorsCode
plugins:
- flow
- flow-resolvers
// in your enums.js
export enum ColorsCode {
MY_RED = '#FF0000',
MY_BLUE = '#0000FF'
}
// in your resolvers.js
import type { Resolvers } from './resolvers-types'
import { ColorsCode } from './enums'
const resolvers: Resolvers = {
Color: {
RED: ColorsCode.MY_RED,
BLUE: ColorsCode.MY_BLUE
},
Query: {
favoriteColor: () => ColorsCode.MY_RED // Now you cn return this, and it will be mapped to your actual GraphQL enum
}
}
You can also define the same with explicit enum values:
schema: schema.graphql
generates:
./resolvers-types.js:
config:
enumValues:
Color:
RED: '#FF0000'
BLUE: '#0000FF'
plugins:
- flow
- flow-resolvers
Or, with mappers:
schema: schema.graphql
generates:
./resolvers-types.js:
config:
mappers:
Color: ./enums#ColorsCode
plugins:
- flow
- flow-resolvers
Package Details
MIT2.2.12May 11th, 202243568