List & Non-Null Types

List Types

GraphQL list types represent a list of values of a specific type. In @graphql-ts/schema, you can create a list type by calling the g.list function with the type of the list as the argument. They can be used in both input and output types.

schema.ts
schema.graphql

const 
const Query: GObjectType<unknown, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
Query = 
const g: GWithContext<{
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
g.
object: <unknown>(youOnlyNeedToPassATypeParameterToThisFunctionYouPassTheActualRuntimeArgsOnTheResultOfThisFunction?: {
    youOnlyNeedToPassATypeParameterToThisFunctionYouPassTheActualRuntimeArgsOnTheResultOfThisFunction: true;
}) => <Fields, Interfaces>(config: {
    fields: Fields | (() => Fields);
    interfaces?: [...Interfaces];
} & Omit<GraphQLObjectTypeConfig<unknown, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>, "fields" | "interfaces">) => GObjectType<unknown, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
object()({
  
name: string
name: "Query",
  
fields: {
    users: GField<unknown, {
        ids: GArg<GNonNull<GList<GNonNull<GScalarType<string, string>>>>, false>;
    }, GList<GObjectType<UserSource, {
        fetchUsers: (ids: string[]) => Promise<UserSource[]>;
    }>>, unknown, {
        fetchUsers: (ids: string[]) => Promise<UserSource[]>;
    }>;
} | (() => {
    users: GField<unknown, {
        ids: GArg<GNonNull<GList<GNonNull<GScalarType<string, string>>>>, false>;
    }, GList<GObjectType<UserSource, {
        fetchUsers: (ids: string[]) => Promise<UserSource[]>;
    }>>, unknown, {
        fetchUsers: (ids: string[]) => Promise<UserSource[]>;
    }>;
})
fields: {
    
users: GField<unknown, {
    ids: GArg<GNonNull<GList<GNonNull<GScalarType<string, string>>>>, false>;
}, GList<GObjectType<UserSource, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>>, unknown, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
users: 
const g: GWithContext<{
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
g.
field: <unknown, GList<GObjectType<UserSource, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>>, (_: unknown, args: {
    readonly ids: string[];
}, context: {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}) => Promise<UserSource[]>, {
    ids: GArg<GNonNull<GList<GNonNull<GScalarType<string, string>>>>, false>;
}>(field: FieldFuncArgs<unknown, {
    ids: GArg<GNonNull<GList<GNonNull<GScalarType<string, string>>>>, false>;
}, GList<...>, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}> & {
    ...;
}) => GField<...>
field({
      
type: GList<GObjectType<UserSource, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>>
type: 
const g: GWithContext<{
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
g.
list: <GObjectType<UserSource, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>>(of: GObjectType<UserSource, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>) => GList<GObjectType<UserSource, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>>
list(
const User: GObjectType<UserSource, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
User),
      
args?: {
    ids: GArg<GNonNull<GList<GNonNull<GScalarType<string, string>>>>, false>;
}
args: {
        
ids: GArg<GNonNull<GList<GNonNull<GScalarType<string, string>>>>, false>
ids: 
const g: GWithContext<{
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
g.
arg: <GNonNull<GList<GNonNull<GScalarType<string, string>>>>, undefined>(arg: {
    type: GNonNull<GList<GNonNull<GScalarType<string, string>>>>;
    description?: Maybe<string>;
    extensions?: (Readonly<GraphQLInputFieldExtensions> & Readonly<GraphQLArgumentExtensions>) | null | undefined;
    astNode?: Maybe<InputValueDefinitionNode>;
    deprecationReason?: Maybe<...>;
} & {
    ...;
}) => GArg<...>
arg({ 
type: GNonNull<GList<GNonNull<GScalarType<string, string>>>>
type: 
const g: GWithContext<{
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
g.
nonNull: <GList<GNonNull<GScalarType<string, string>>>>(of: GList<GNonNull<GScalarType<string, string>>>) => GNonNull<GList<GNonNull<GScalarType<string, string>>>>
nonNull(
const g: GWithContext<{
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
g.
list: <GNonNull<GScalarType<string, string>>>(of: GNonNull<GScalarType<string, string>>) => GList<GNonNull<GScalarType<string, string>>>
list(
const g: GWithContext<{
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
g.
nonNull: <GScalarType<string, string>>(of: GScalarType<string, string>) => GNonNull<GScalarType<string, string>>
nonNull(
const g: GWithContext<{
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>
g.
type ID: GScalarType<string, string>
ID))) }),
      },
      
resolve: ((source: unknown, args: {
    readonly ids: string[];
}, context: {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}, info: GraphQLResolveInfo) => InferValueFromOutputType<GList<GObjectType<UserSource, {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}>>>) & ((_: unknown, args: {
    readonly ids: string[];
}, context: {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}) => Promise<UserSource[]>)
resolve(
_: unknown
_, 
args: {
    readonly ids: string[];
}
args, 
context: {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}
context) {
        return 
context: {
    fetchUsers: (ids: string[]) => Promise<UserSource[]>;
}
context.
fetchUsers: (ids: string[]) => Promise<UserSource[]>
fetchUsers(
args: {
    readonly ids: string[];
}
args.
ids: string[]
ids);
      },
    }),
  },
});

type Query {
  users(ids: [ID!]!): [User]
}

type User {
  id: ID!
  name: String!
}

Non-Null Types

In GraphQL, by default every type can also be null (and in the case of input types, undefined as well). You can make a type non-null by wrapping it in the g.nonNull function. Non-null types can be used in both input and output types.

schema.ts
schema.graphql

type 
type UserSource = {
    id: string;
    name: string;
}
UserSource = { 
id: string
id: string; 
name: string
name: string };
const 
const User: GObjectType<UserSource, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
User = 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
object: <UserSource>(youOnlyNeedToPassATypeParameterToThisFunctionYouPassTheActualRuntimeArgsOnTheResultOfThisFunction?: {
    youOnlyNeedToPassATypeParameterToThisFunctionYouPassTheActualRuntimeArgsOnTheResultOfThisFunction: true;
}) => <Fields, Interfaces>(config: {
    fields: Fields | (() => Fields);
    interfaces?: [...Interfaces];
} & Omit<GraphQLObjectTypeConfig<UserSource, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>, "fields" | "interfaces">) => GObjectType<...>
object<
type UserSource = {
    id: string;
    name: string;
}
UserSource>()({
  
name: string
name: "User",
  
fields: {
    id: GField<UserSource, any, GNonNull<GScalarType<string, string>>, ImpliedResolver<any, GNonNull<GScalarType<string, string>>, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>;
    name: GField<UserSource, any, GNonNull<GScalarType<string, string>>, ImpliedResolver<any, GNonNull<GScalarType<string, string>>, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>;
} | (() => {
    id: GField<UserSource, any, GNonNull<GScalarType<string, string>>, ImpliedResolver<any, GNonNull<GScalarType<string, string>>, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>;
    name: GField<UserSource, any, GNonNull<GScalarType<string, string>>, ImpliedResolver<any, GNonNull<GScalarType<string, string>>, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>;
})
fields: {
    
id: GField<UserSource, any, GNonNull<GScalarType<string, string>>, ImpliedResolver<any, GNonNull<GScalarType<string, string>>, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
id: 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
field: <UserSource, GNonNull<GScalarType<string, string>>, unknown, any>(field: FieldFuncArgs<UserSource, any, GNonNull<GScalarType<string, string>>, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}> & {
    resolve?: (source: UserSource, args: {}, context: {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }, info: GraphQLResolveInfo) => InferValueFromOutputType<GNonNull<GScalarType<string, string>>>;
}) => GField<...>
field({ 
type: GNonNull<GScalarType<string, string>>
type: 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
nonNull: <GScalarType<string, string>>(of: GScalarType<string, string>) => GNonNull<GScalarType<string, string>>
nonNull(
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
type ID: GScalarType<string, string>
ID) }),
    
name: GField<UserSource, any, GNonNull<GScalarType<string, string>>, ImpliedResolver<any, GNonNull<GScalarType<string, string>>, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
name: 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
field: <UserSource, GNonNull<GScalarType<string, string>>, unknown, any>(field: FieldFuncArgs<UserSource, any, GNonNull<GScalarType<string, string>>, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}> & {
    resolve?: (source: UserSource, args: {}, context: {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }, info: GraphQLResolveInfo) => InferValueFromOutputType<GNonNull<GScalarType<string, string>>>;
}) => GField<...>
field({ 
type: GNonNull<GScalarType<string, string>>
type: 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
nonNull: <GScalarType<string, string>>(of: GScalarType<string, string>) => GNonNull<GScalarType<string, string>>
nonNull(
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
type String: GScalarType<string, string>
String) }),
  },
});

const 
const Query: GObjectType<unknown, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
Query = 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
object: <unknown>(youOnlyNeedToPassATypeParameterToThisFunctionYouPassTheActualRuntimeArgsOnTheResultOfThisFunction?: {
    youOnlyNeedToPassATypeParameterToThisFunctionYouPassTheActualRuntimeArgsOnTheResultOfThisFunction: true;
}) => <Fields, Interfaces>(config: {
    fields: Fields | (() => Fields);
    interfaces?: [...Interfaces];
} & Omit<GraphQLObjectTypeConfig<unknown, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>, "fields" | "interfaces">) => GObjectType<unknown, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
object()({
  
name: string
name: "Query",
  
fields: {
    user: GField<unknown, {
        id: GArg<GNonNull<GScalarType<string, string>>, false>;
    }, GObjectType<UserSource, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>, unknown, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>;
} | (() => {
    user: GField<unknown, {
        id: GArg<GNonNull<GScalarType<string, string>>, false>;
    }, GObjectType<UserSource, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>, unknown, {
        fetchUser: (id: string) => Promise<UserSource | null>;
    }>;
})
fields: {
    
user: GField<unknown, {
    id: GArg<GNonNull<GScalarType<string, string>>, false>;
}, GObjectType<UserSource, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>, unknown, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
user: 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
field: <unknown, GObjectType<UserSource, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>, (_: unknown, args: {
    readonly id: string;
}, context: {
    fetchUser: (id: string) => Promise<UserSource | null>;
}) => Promise<UserSource | null>, {
    id: GArg<GNonNull<GScalarType<string, string>>, false>;
}>(field: FieldFuncArgs<unknown, {
    id: GArg<GNonNull<GScalarType<string, string>>, false>;
}, GObjectType<UserSource, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}> & {
    ...;
}) => GField<...>
field({
      
type: GObjectType<UserSource, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
type: 
const User: GObjectType<UserSource, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
User,
      
args?: {
    id: GArg<GNonNull<GScalarType<string, string>>, false>;
}
args: {
        
id: GArg<GNonNull<GScalarType<string, string>>, false>
id: 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
arg: <GNonNull<GScalarType<string, string>>, undefined>(arg: {
    type: GNonNull<GScalarType<string, string>>;
    description?: Maybe<string>;
    extensions?: (Readonly<GraphQLInputFieldExtensions> & Readonly<GraphQLArgumentExtensions>) | null | undefined;
    astNode?: Maybe<InputValueDefinitionNode>;
    deprecationReason?: Maybe<string>;
} & {
    defaultValue?: undefined;
}) => GArg<GNonNull<GScalarType<...>>, false>
arg({ 
type: GNonNull<GScalarType<string, string>>
type: 
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
nonNull: <GScalarType<string, string>>(of: GScalarType<string, string>) => GNonNull<GScalarType<string, string>>
nonNull(
const g: GWithContext<{
    fetchUser: (id: string) => Promise<UserSource | null>;
}>
g.
type ID: GScalarType<string, string>
ID) }),
      },
      
resolve: ((source: unknown, args: {
    readonly id: string;
}, context: {
    fetchUser: (id: string) => Promise<UserSource | null>;
}, info: GraphQLResolveInfo) => InferValueFromOutputType<GObjectType<UserSource, {
    fetchUser: (id: string) => Promise<UserSource | null>;
}>>) & ((_: unknown, args: {
    readonly id: string;
}, context: {
    fetchUser: (id: string) => Promise<UserSource | null>;
}) => Promise<UserSource | null>)
resolve(
_: unknown
_, 
args: {
    readonly id: string;
}
args, 
context: {
    fetchUser: (id: string) => Promise<UserSource | null>;
}
context) {
        return 
context: {
    fetchUser: (id: string) => Promise<UserSource | null>;
}
context.
fetchUser: (id: string) => Promise<UserSource | null>
fetchUser(
args: {
    readonly id: string;
}
args.
id: string
id);
      },
    }),
  },
});

type Query {
  user(id: ID!): User
}

type User {
  id: ID!
  name: String!
}