Tune up project linting (#1317)

- move lints configuration to `Cargo.toml`
- omit using `#[deny]` for rustc lints for better future compatibility
- use `#[expect]` instead of `#[allow]` asap

Author: tyranron

Cargo.toml

@@ -2,6 +2,7 @@
 resolver = "1" # unifying Cargo features asap for Book tests
 members = [
     "benches",
+    "book",
     "juniper_codegen",
     "juniper",
     "juniper_hyper",

benches/Cargo.toml

@@ -6,14 +6,23 @@ authors = ["Christoph Herzog <chris@theduke.at>"]
 publish = false
 
 [dependencies]
-dataloader = "0.18" # for Book only
-futures = "0.3"
 juniper = { path = "../juniper" }
 
 [dev-dependencies]
 criterion = "0.5"
 tokio = { version = "1.0", features = ["rt-multi-thread"] }
 
+[lints.clippy]
+allow_attributes = "warn"
+allow_attributes_without_reason = "warn"
+[lints.rust]
+closure_returning_async_block = "warn"
+future_incompatible = { level = "warn", priority = -1 }
+impl_trait_redundant_captures = "warn"
+non_ascii_idents = "forbid"
+unsafe_code = "forbid"
+unused_crate_dependencies = "warn"
+
 [[bench]]
 name = "benchmark"
 harness = false

benches/src/lib.rs

@@ -1,3 +1,9 @@
+#[cfg(test)]
+mod for_benches_only {
+    use criterion as _;
+    use tokio as _;
+}
+
 use juniper::{
     DefaultScalarValue, EmptyMutation, EmptySubscription, ExecutionError, FieldError, GraphQLEnum,
     GraphQLObject, RootNode, Value, Variables, graphql_object,

book/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "juniper_book"
+version = "0.0.0"
+edition = "2024"
+authors = ["Kai Ren <tyranron@gmail.com>"]
+publish = false
+
+[dependencies]
+dataloader = "0.18" # for Book only
+
+[lints.clippy]
+allow_attributes = "warn"
+allow_attributes_without_reason = "warn"
+[lints.rust]
+closure_returning_async_block = "warn"
+future_incompatible = { level = "warn", priority = -1 }
+impl_trait_redundant_captures = "warn"
+non_ascii_idents = "forbid"
+unsafe_code = "forbid"
+unused_crate_dependencies = "warn"

book/src/lib.rs

@@ -0,0 +1,3 @@
+//! Crate keeping dependencies for running Book tests.
+
+use dataloader as _;

book/src/quickstart.md

@@ -27,7 +27,7 @@ Exposing simple enums and structs as [GraphQL] types is just a matter of adding
 For more advanced mappings, [Juniper] provides multiple macros to map your [Rust] types to a [GraphQL schema][schema]. The most important one is the [`#[graphql_object]` attribute][2] that is used for declaring a [GraphQL object] with resolvers (typically used for declaring [`Query` and `Mutation` roots][1]).
 
 ```rust
-# # ![allow(unused_variables)]
+# #![expect(unused_variables, reason = "example")]
 # extern crate juniper;
 #
 # use std::fmt::Display;

book/src/types/enums.md

@@ -112,7 +112,7 @@ enum StarWarsEpisode {
 
 By default, all [enum][3] variants are included in the generated [GraphQL enum][0] type as values. To prevent including a specific variant, annotate it with the `#[graphql(ignore)]` attribute:
 ```rust
-# #![allow(dead_code)]
+# #![expect(dead_code, reason = "example")]
 # extern crate juniper;
 # use juniper::GraphQLEnum;
 #

book/src/types/input_objects.md

@@ -7,7 +7,7 @@ Input objects
 
 In [Juniper], defining a [GraphQL input object][0] is quite straightforward and similar to how [trivial GraphQL objects are defined](objects/index.md) - by using the [`#[derive(GraphQLInputObject)]` attribute][2] on a [Rust struct][struct]:
 ```rust
-# #![allow(unused_variables)]
+# #![expect(unused_variables, reason = "example")]
 # extern crate juniper;
 # use juniper::{GraphQLInputObject, GraphQLObject, graphql_object};
 #

book/src/types/interfaces.md

@@ -356,7 +356,7 @@ trait Person {
 
 By default, all [struct][24] fields or [trait][20] methods are considered as [GraphQL fields][4]. If a helper method is needed, or it should be ignored for some reason, then it should be marked with the `#[graphql(ignore)]` attribute:
 ```rust
-# #![allow(dead_code)]
+# #![expect(dead_code, reason = "example")]
 # extern crate juniper;
 # use std::marker::PhantomPinned;
 # use juniper::{graphql_interface, GraphQLInterface};

book/src/types/objects/complex_fields.md

@@ -165,7 +165,7 @@ impl Person {
 
 By default, all methods of an [`impl` block][6] are exposed as [GraphQL fields][4]. If a method should not be exposed as a [GraphQL field][4], it should be defined in a separate [`impl` block][6] or marked with the `#[graphql(ignore)]` attribute:
 ```rust
-# #![allow(dead_code)]
+# #![expect(dead_code, reason = "example")]
 # extern crate juniper;
 # use juniper::graphql_object;
 #