6 releases (breaking)
new 0.5.0 | Jan 6, 2025 |
---|---|
0.4.0 | Jun 11, 2024 |
0.3.0 | Feb 6, 2024 |
0.2.0 | Dec 14, 2023 |
0.1.0 | Oct 31, 2023 |
#623 in HTTP server
390KB
9K
SLoC
graphql-composition
An implementation of GraphQL federated schema composition.
Example
use graphql_composition::{Subgraphs, compose, render_federated_sdl};
let user_subgraph = r#"
extend schema
@link(url: "https://specs.apollo.dev/federation/v2.3",
import: ["@key"])
type Query {
findUserByEmail(email: String!): User
}
type User @key(fields: "id") {
id: ID!
name: String!
}
"#;
let cart_subgraph = r#"
extend schema
@link(url: "https://specs.apollo.dev/federation/v2.3",
import: ["@key", "@shareable"])
type User @key(fields: "id") {
id: ID!
cart: Cart
}
type Cart @shareable {
items: [String!]!
}
"#;
let mut subgraphs = Subgraphs::default();
subgraphs.ingest_str(&user_subgraph, "users-service", "http://users.example.com").unwrap();
subgraphs.ingest_str(&cart_subgraph, "carts-service", "http://carts.example.com").unwrap();
let composed = compose(&subgraphs).into_result().unwrap();
let composed = render_federated_sdl(&composed).unwrap();
let expected = r#"
directive @core(feature: String!) repeatable on SCHEMA
directive @join__owner(graph: join__Graph!) on OBJECT
directive @join__type(
graph: join__Graph!
key: join__FieldSet
resolvable: Boolean = true
) repeatable on OBJECT | INTERFACE
directive @join__field(
graph: join__Graph
requires: join__FieldSet
provides: join__FieldSet
) on FIELD_DEFINITION
directive @join__graph(name: String!, url: String!) on ENUM_VALUE
directive @join__implements(graph: join__Graph!, interface: String!) repeatable on OBJECT | INTERFACE
directive @join__unionMember(graph: join__Graph!, member: String!) repeatable on UNION
scalar join__FieldSet
enum join__Graph {
USERS_SERVICE @join__graph(name: "users-service", url: "http://users.example.com")
CARTS_SERVICE @join__graph(name: "carts-service", url: "http://carts.example.com")
}
type User
@join__type(graph: USERS_SERVICE, key: "id")
@join__type(graph: CARTS_SERVICE, key: "id")
{
cart: Cart @join__field(graph: CARTS_SERVICE)
id: ID!
name: String! @join__field(graph: USERS_SERVICE)
}
type Cart
@join__type(graph: CARTS_SERVICE)
{
items: [String!]!
}
type Query
{
findUserByEmail(email: String!): User @join__field(graph: USERS_SERVICE)
}
"#;
assert_eq!(expected.trim(), composed.trim());
Features
- The output is a structured, serializable format with all relevant relationships (FederatedGraph).
- FederatedGraph can be rendered to GraphQL SDL (see the example above).
- Good composition error messages.
Status
The crate is being actively developed and maintained.
Dependencies
~7.5MB
~115K SLoC