Document features

Cargo.toml

@@ -17,6 +17,8 @@ readme = "README.md"
 default = ["apollo_tracing", "bson", "chrono", "chrono-tz", "log", "multipart", "tracing", "url"]
 apollo_tracing = ["chrono"]
 multipart = ["multer", "bytes", "tempfile"]
+# Used for doc(cfg())
+nightly = []
 
 [dependencies]
 async-graphql-derive = { path = "derive", version = "2.0.0-alpha.8" }
@@ -52,6 +54,9 @@ tempfile = { version = "3.1.0", optional = true }
 [dev-dependencies]
 async-std = { version = "1.5.0", features = ["attributes"] }
 
+[package.metadata.docs.rs]
+features = ["nightly"]
+
 [workspace]
 members = [
     "parser",

src/error.rs

@@ -331,6 +331,7 @@ pub enum ParseRequestError {
     /// The request's multipart data was invalid.
     #[error("Invalid multipart data")]
     #[cfg(feature = "multipart")]
+    #[cfg_attr(feature = "nightly", doc(cfg(feature = "multipart")))]
     InvalidMultipart(multer::Error),
 
     /// Missing "operators" part for multipart request.

src/extensions/apollo_tracing.rs

@@ -51,6 +51,7 @@ impl Serialize for ResolveStat {
 /// have access to performance traces alongside the data returned by your query.
 /// It's already supported by `Apollo Engine`, and we're excited to see what other kinds of
 /// integrations people can build on top of this format.
+#[cfg_attr(feature = "nightly", doc(cfg(feature = "apollo_tracing")))]
 pub struct ApolloTracing {
     start_time: DateTime<Utc>,
     end_time: DateTime<Utc>,

src/extensions/logger.rs

@@ -7,6 +7,7 @@ use std::borrow::Cow;
 use uuid::Uuid;
 
 /// Logger extension
+#[cfg_attr(feature = "nightly", doc(cfg(feature = "log")))]
 pub struct Logger {
     id: Uuid,
     enabled: bool,

src/extensions/tracing.rs

@@ -8,8 +8,9 @@ use uuid::Uuid;
 ///
 /// # References
 ///
-/// https://crates.io/crates/tracing
+/// <https://crates.io/crates/tracing>
 #[derive(Default)]
+#[cfg_attr(feature = "nightly", doc(cfg(feature = "tracing")))]
 pub struct Tracing {
     root_id: Option<Id>,
     fields: BTreeMap<usize, Id>,

src/http/mod.rs

@@ -21,6 +21,7 @@ use futures::AsyncReadExt;
 /// If the content type is multipart it will use `receive_multipart`, otherwise it will use
 /// `receive_json`.
 #[cfg(feature = "multipart")]
+#[cfg_attr(feature = "nightly", doc(cfg(feature = "multipart")))]
 pub async fn receive_body(
     content_type: Option<impl AsRef<str>>,
     body: impl AsyncRead + Send + 'static,

src/http/multipart.rs

@@ -12,6 +12,7 @@ use std::task::{Context, Poll};
 /// Options for `receive_multipart`.
 #[derive(Default, Clone)]
 #[non_exhaustive]
+#[cfg_attr(feature = "nightly", doc(cfg(feature = "multipart")))]
 pub struct MultipartOptions {
     /// The maximum file size.
     pub max_file_size: Option<usize>,
@@ -38,6 +39,7 @@ impl MultipartOptions {
 }
 
 /// Receive a multipart request.
+#[cfg_attr(feature = "nightly", doc(cfg(feature = "multipart")))]
 pub async fn receive_multipart(
     body: impl AsyncRead + Send + 'static,
     boundary: impl Into<String>,

src/lib.rs

@@ -59,8 +59,8 @@
 //! Licensed under either of
 //!
 //! * Apache License, Version 2.0,
-//! (./LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
+//! (./LICENSE-APACHE or <http://www.apache.org/licenses/LICENSE-2.0>)
-//! * MIT license (./LICENSE-MIT or http://opensource.org/licenses/MIT)
+//! * MIT license (./LICENSE-MIT or <http://opensource.org/licenses/MIT>)
 //! at your option.
 //!
 //! ## References
@@ -91,12 +91,25 @@
 //!
 //! Now a HTML report is available at `benchmark/target/criterion/report`.
 //!
+//! # Crate features
+//!
+//! This crate offers the following features, all of which are activated by default:
+//!
+//! - `apollo_tracing`: Enable the [Apollo tracing
+//! extension](extensions/struct.ApolloTracing.html).
+//! - `log`: Enable the [logger extension](extensions/struct.Logger.html).
+//! - `tracing`: Enable the [tracing extension](extensions/struct.Tracing.html).
+//! - `multipart`: Support [sending files over HTTP multipart](http/fn.receive_multipart.html).
+//! - `bson`: Integrate with the [`bson` crate](https://crates.io/crates/bson).
+//! - `chrono`: Integrate with the [`chrono` crate](https://crates.io/crates/chrono).
+//! - `chrono-tz`: Integrate with the [`chrono-tz` crate](https://crates.io/crates/chrono-tz).
+//! - `url`: Integrate with the [`url` crate](https://crates.io/crates/url).
 
 #![warn(missing_docs)]
-#![allow(clippy::needless_lifetimes)]
 #![allow(clippy::trivially_copy_pass_by_ref)]
 #![recursion_limit = "256"]
 #![forbid(unsafe_code)]
+#![cfg_attr(feature = "nightly", feature(doc_cfg))]
 
 mod base;
 mod context;

src/types/id.rs

@@ -10,6 +10,7 @@ use std::ops::{Deref, DerefMut};
 ///
 /// The input is a `&str`, `String`, `usize` or `uuid::UUID`, and the output is a string.
 #[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Debug, Serialize, Deserialize)]
+#[serde(transparent)]
 pub struct ID(pub String);
 
 impl Deref for ID {