A single file schema first rust graphql server

server.rs

#!/usr/bin/env cargo
//! ```cargo
//! [dependencies]
//! futures = "0.3"
//! graphql-mocks = { git = "https://github.com/grafbase/grafbase.git", rev = "e23190a" }
//! serde_json = "1"
//! tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
//! ```

use graphql_mocks::{
    dynamic::{DynamicSchema, ResolverContext},
    MockGraphQlServer,
};
use serde_json::json;

#[tokio::main]
async fn main() {
    let server = MockGraphQlServer::new(
        DynamicSchema::builder(
            r#"
            type Query {
               products(first: Int, after: String): ProductConnection @listSize(
                 slicingArguments: ["first"]
                 sizedFields: ["edges"]
               )
             }

             type ProductConnection {
               edges: [ProductEdge]
               totalSize: Int! @cost(weight: 50)
             }

             type ProductEdge {
               node: Product,
               cursor: String
             }

             type Product {
               id: ID!
             }
        "#,
        )
        .with_resolver("Query", "products", |context: ResolverContext<'_>| {
            let first = context.args.get("first").unwrap();
            let num = first.deserialize::<usize>().unwrap();
            let edges = std::iter::repeat(())
                .enumerate()
                .map(|(i, _)| {
                    let cursor = format!("cursor_{i}");
                    json!({
                        "node": {"id": i},
                        "cursor": cursor,
                    })
                })
                .take(num)
                .collect::<Vec<_>>();

            Some(json!({
                "edges": edges,
                "totalSize": 10000
            }))
        })
        .finish(),
    )
    .await;

    println!("Server running on {}", server.port());

    futures::future::pending::<()>().await;
}