Inheritance

Inheritance is naturally supported by graphql-composer-decorators, when you use the keyword extends, it will determine the type of the inherited class and get its GraphQL type and add the fields to the inherited type.

Inheritance is not natively supported by GraphQL, graphql-composer-decorators then takes care of copying the fields.

Example of inheritance

Both classes must be decorated with the same GraphQL type in order to use inheritance (here @ObjectType and @InputType).

@ObjectType()
@InputType("AnimalInput")
class Animal {
  @Field()
  name: string;
}

@ObjectType()
@InputType("CatInput")
class Cat extends Animal {
  @Field()
  meow: thong;
}

Will give in SDL:

type Animal {
  name: String
}

type Cat {
  name: String
  meow: Thong
}

input AnimalInput {
  name: String
}

input CatInput {
  name: String
  meow: Thong
}