#![allow(unused_variables, unused_imports, dead_code, unused_mut)]
mod helpers;
use assert_json_diff::{assert_json_eq, assert_json_include};
use helpers::{SortedExtension, StatsHash};
use juniper::{Executor, FieldError, FieldResult};
use juniper_eager_loading::{
prelude::*, EagerLoading, HasMany, HasManyThrough, HasOne, OptionHasOne,
};
use juniper_from_schema::graphql_schema;
use serde_json::{json, Value};
use std::sync::atomic::{AtomicUsize, Ordering};
use std::{borrow::Borrow, collections::HashMap, hash::Hash};
graphql_schema! {
schema {
query: Query
}
type Query {
search: [HasCountry!]! @juniper(ownership: "owned")
}
type User implements HasCountry {
id: Int!
country: Country!
}
type City implements HasCountry {
id: Int!
country: Country!
}
interface HasCountry {
country: Country!
}
type Country {
id: Int!
}
}
mod models {
use juniper_eager_loading::LoadFrom;
#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Debug)]
pub struct User {
pub id: i32,
pub country_id: i32,
}
#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Debug)]
pub struct City {
pub id: i32,
pub country_id: i32,
}
#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Debug)]
pub struct Country {
pub id: i32,
}
impl LoadFrom<i32> for Country {
type Error = Box<dyn std::error::Error>;
type Context = super::Context;
fn load(ids: &[i32], _: &(), ctx: &Self::Context) -> Result<Vec<Self>, Self::Error> {
let models = ctx
.db
.countries
.all_values()
.into_iter()
.filter(|value| ids.contains(&value.id))
.cloned()
.collect::<Vec<_>>();
Ok(models)
}
}
}
pub struct Db {
users: StatsHash<i32, models::User>,
cities: StatsHash<i32, models::City>,
countries: StatsHash<i32, models::Country>,
}
pub struct Context {
db: Db,
}
impl juniper::Context for Context {}
pub struct Query;
impl QueryFields for Query {
fn field_search<'a>(
&self,
executor: &Executor<'a, Context>,
trail: &QueryTrail<'a, HasCountry, Walked>,
) -> FieldResult<Vec<HasCountry>> {
let ctx = executor.context();
let mut user_models = ctx
.db
.users
.all_values()
.into_iter()
.cloned()
.collect::<Vec<_>>();
let mut users = User::from_db_models(&user_models);
User::eager_load_all_children_for_each(&mut users, &user_models, &ctx, &trail.downcast())?;
let mut city_models = ctx
.db
.cities
.all_values()
.into_iter()
.cloned()
.collect::<Vec<_>>();
let mut cities = City::from_db_models(&city_models);
City::eager_load_all_children_for_each(&mut cities, &city_models, &ctx, &trail.downcast())?;
let mut has_countries = vec![];
has_countries.extend(users.into_iter().map(HasCountry::from).collect::<Vec<_>>());
has_countries.extend(cities.into_iter().map(HasCountry::from).collect::<Vec<_>>());
Ok(has_countries)
}
}
#[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Debug, EagerLoading)]
#[eager_loading(context = Context, error = Box<dyn std::error::Error>)]
pub struct User {
user: models::User,
#[has_one(default)]
country: HasOne<Country>,
}
impl UserFields for User {
fn field_id<'a>(&self, _: &Executor<'a, Context>) -> FieldResult<&i32> {
Ok(&self.user.id)
}
fn field_country<'a>(
&self,
executor: &Executor<'a, Context>,
trail: &QueryTrail<'a, Country, Walked>,
) -> FieldResult<&Country> {
Ok(self.country.try_unwrap()?)
}
}
#[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Debug, EagerLoading)]
#[eager_loading(context = Context, error = Box<dyn std::error::Error>)]
pub struct City {
city: models::City,
#[has_one(default)]
country: HasOne<Country>,
}
impl CityFields for City {
fn field_id<'a>(&self, _: &Executor<'a, Context>) -> FieldResult<&i32> {
Ok(&self.city.id)
}
fn field_country<'a>(
&self,
executor: &Executor<'a, Context>,
trail: &QueryTrail<'a, Country, Walked>,
) -> FieldResult<&Country> {
Ok(self.country.try_unwrap()?)
}
}
#[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Debug, EagerLoading)]
#[eager_loading(context = Context, error = Box<dyn std::error::Error>)]
pub struct Country {
country: models::Country,
}
impl CountryFields for Country {
fn field_id<'a>(&self, _: &Executor<'a, Context>) -> FieldResult<&i32> {
Ok(&self.country.id)
}
}
#[test]
fn loading_users_and_associations() {
let mut countries = StatsHash::new("countries");
let country = models::Country { id: 10 };
countries.insert(country.id, country.clone());
let mut users = StatsHash::new("users");
let user = models::User {
id: 10,
country_id: country.id,
};
users.insert(user.id, user.clone());
let mut cities = StatsHash::new("cities");
let city = models::City {
id: 10,
country_id: country.id,
};
cities.insert(city.id, city.clone());
let db = Db {
users,
countries,
cities,
};
let (json, counts) = run_query(
r#"
query Test {
search {
country {
id
}
}
}
"#,
db,
);
assert_json_include!(
expected: json!({
"search": [
{ "country": { "id": country.id } },
{ "country": { "id": country.id } },
]
}),
actual: json.clone(),
);
assert_eq!(1, counts.user_reads);
assert_eq!(1, counts.city_reads);
assert_eq!(2, counts.country_reads);
}
struct DbStats {
user_reads: usize,
city_reads: usize,
country_reads: usize,
}
fn run_query(query: &str, db: Db) -> (Value, DbStats) {
let ctx = Context { db };
let (result, errors) = juniper::execute(
query,
None,
&Schema::new(Query, juniper::EmptyMutation::new()),
&juniper::Variables::new(),
&ctx,
)
.unwrap();
if !errors.is_empty() {
panic!(
"GraphQL errors\n{}",
serde_json::to_string_pretty(&errors).unwrap()
);
}
let json: Value = serde_json::from_str(&serde_json::to_string(&result).unwrap()).unwrap();
println!("{}", serde_json::to_string_pretty(&json).unwrap());
(
json,
DbStats {
user_reads: ctx.db.users.reads_count(),
country_reads: ctx.db.countries.reads_count(),
city_reads: ctx.db.cities.reads_count(),
},
)
}