Implemented CORS header handler middleware (#262)

* feat: Add cors middleware

* test: Add cors test code

* feat: export CorsMiddleware

* feat: Add cors example

* $cargo fmt

* doc: move example/cors.rs

* doc: Add README

* doc: Add doc comment

* fix example doc comment

* fix: Changed type to option

* feat: Add credentials header at preflight request

* fix: Attach an expose header when requesting preflight

* $cargo fmt

* fix: remove debug pring

* refactor: move build preflight response

* fix: Remove echo_back option

* fix: fix type OPTION -> OPTIONS

* refactor: tide-cors to optional dependence

* $cargo fmt

* refactor: imple arg to generic argument

* fix typo

* refactor: using 'match'

Cargo.toml

@@ -19,15 +19,17 @@ repository = "https://github.com/rustasync/tide"
 version = "0.2.0"
 
 [features]
-default = ["hyper", "cookies"]
+default = ["hyper", "cookies", "cors"]
 cookies = ["tide-cookies"]
+cors = ["tide-cors"]
 hyper = ["tide-core/http-service-hyper"]
 
 [dependencies]
 futures-preview = "0.3.0-alpha.16"
 http = "0.1"
 http-service = "0.2.0"
 tide-cookies = { path = "./tide-cookies", optional = true }
+tide-cors = { path = "./tide-cors", optional = true }
 tide-core = { path = "./tide-core" }
 tide-headers = { path = "./tide-headers" }
 tide-log = { path = "./tide-log" }
@@ -55,6 +57,7 @@ members = [
     "tide-compression",
     "tide-cookies",
     "tide-core",
+    "tide-cors",
     "tide-forms",
     "tide-headers",
     "tide-log",

src/lib.rs

@@ -26,6 +26,10 @@ pub use http;
 #[doc(inline)]
 pub use tide_cookies as cookies;
 
+#[cfg(feature = "cors")]
+#[doc(inline)]
+pub use tide_cors as cors;
+
 #[doc(inline)]
 pub use tide_core::{
     err_fmt,
@@ -62,6 +66,9 @@ pub mod middleware {
     pub use tide_headers::DefaultHeaders;
     pub use tide_log::RequestLogger;
 
+    #[cfg(feature = "cors")]
+    pub use tide_cors::CorsMiddleware;
+
     #[cfg(feature = "cookies")]
     pub use tide_cookies::CookiesMiddleware;
 }

tide-cors/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "tide-cors"
+version = "0.2.0"
+authors = [
+  "Tide Developers",
+]
+description = "Cors middleware and extensions for Tide"
+documentation = "https://docs.rs/tide-cors"
+readme = "README.md"
+repository = "https://github.com/rustasync/tide"
+license = "MIT OR Apache-2.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+futures-preview = "0.3.0-alpha.16"
+http = "0.1"
+http-service = "0.2.0"
+tide-core = { path = "../tide-core" }
+
+[dev-dependencies]
+tide = { path = "../" }
+http-service-mock = "0.2.0"

tide-cors/README.md

@@ -0,0 +1,38 @@
+# tide-cors
+
+This crate provides cors-related middleware for Tide.
+
+## Examples
+
+Examples are in the `/examples` folder of this crate.
+
+```rust
+#![feature(async_await)]
+
+use http::header::HeaderValue;
+use tide::middleware::CorsMiddleware;
+
+fn main() {
+    let mut app = tide::App::new();
+
+    app.middleware(
+        CorsMiddleware::new()
+            .allow_origin(HeaderValue::from_static("*"))
+            .allow_methods(HeaderValue::from_static("GET, POST, OPTIONS")),
+    );
+
+    app.at("/").get(async move |_| "Hello, world!");
+
+    app.run("127.0.0.1:8000").unwrap();
+}
+```
+
+**Simple Example**
+
+You can test the simple example by running `cargo run --example cors` while in this crate's directory, and then running this script in the browser console:
+
+```console
+fetch("http://127.0.0.1:8000")
+```
+
+You will probably get a browser alert when running without cors middleware

tide-cors/examples/cors.rs

@@ -0,0 +1,18 @@
+#![feature(async_await)]
+
+use http::header::HeaderValue;
+use tide::middleware::CorsMiddleware;
+
+fn main() {
+    let mut app = tide::App::new();
+
+    app.middleware(
+        CorsMiddleware::new()
+            .allow_origin(HeaderValue::from_static("*"))
+            .allow_methods(HeaderValue::from_static("GET, POST, OPTIONS")),
+    );
+
+    app.at("/").get(async move |_| "Hello, world!");
+
+    app.run("127.0.0.1:8000").unwrap();
+}

tide-cors/src/lib.rs

@@ -0,0 +1,54 @@
+//! Cors middleware and extensions for Tide
+//!
+//! # tide-cors
+//!
+//! This crate provides cors-related middleware for Tide.
+//!
+//! ## Examples
+//!
+//! Examples are in the `/examples` folder of this crate.
+//!
+//! ```rust, no_run
+//! #![feature(async_await)]
+//!
+//! use http::header::HeaderValue;
+//! use tide::middleware::CorsMiddleware;
+//!
+//! fn main() {
+//!     let mut app = tide::App::new();
+//!
+//!     app.middleware(
+//!         CorsMiddleware::new()
+//!             .allow_origin(HeaderValue::from_static("*"))
+//!             .allow_methods(HeaderValue::from_static("GET, POST, OPTIONS")),
+//!     );
+//!
+//!     app.at("/").get(async move |_| "Hello, world!");
+//!
+//!     app.run("127.0.0.1:8000").unwrap();
+//! }
+//! ```
+//!
+//! **Simple Example**
+//!
+//! You can test the simple example by running `cargo run --example cors` while in this crate's directory, and then running this script in the browser console:
+//!
+//! ```console
+//! fetch("http://127.0.0.1:8000")
+//! ```
+//!
+//! You will probably get a browser alert when running without cors middleware
+//!
+
+#![feature(async_await)]
+#![warn(
+    nonstandard_style,
+    rust_2018_idioms,
+    future_incompatible,
+    missing_debug_implementations,
+    missing_docs
+)]
+
+mod middleware;
+
+pub use self::middleware::CorsMiddleware;