feat: Html responder (#3399)

actix-multipart/README.md

@@ -19,8 +19,6 @@ Multipart form support for Actix Web.
 
 ## Examples
 
-[More available in the examples repo →](https://github.com/actix/examples/tree/master/forms/multipart)
-
 ```rust
 use actix_web::{post, App, HttpServer, Responder};
 
@@ -58,6 +56,8 @@ async fn main() -> std::io::Result<()> {
 
 <!-- cargo-rdme end -->
 
+[More available in the examples repo &rarr;](https://github.com/actix/examples/tree/master/forms/multipart)
+
 Curl request :
 
 ```bash

actix-web/CHANGES.md

@@ -4,6 +4,7 @@
 
 ### Added
 
+- Add `web::Html` responder.
 - Add `HttpRequest::full_url()` method to get the complete URL of the request.
 
 ### Fixed

actix-web/README.md

@@ -109,4 +109,4 @@ This project is licensed under either of the following licenses, at your option:
 
 ## Code of Conduct
 
-Contribution to the actix-web repo is organized under the terms of the Contributor Covenant. The Actix team promises to intervene to uphold that code of conduct.
+Contribution to the `actix/actix-web` repo is organized under the terms of the Contributor Covenant. The Actix team promises to intervene to uphold that code of conduct.

actix-web/src/types/html.rs

@@ -0,0 +1,66 @@
+//! Semantic HTML responder. See [`Html`].
+
+use crate::{
+    http::{
+        header::{self, ContentType, TryIntoHeaderValue},
+        StatusCode,
+    },
+    HttpRequest, HttpResponse, Responder,
+};
+
+/// Semantic HTML responder.
+///
+/// When used as a responder, creates a 200 OK response, sets the correct HTML content type, and
+/// uses the string passed to [`Html::new()`] as the body.
+///
+/// ```
+/// # use actix_web::web::Html;
+/// Html::new("<p>Hello, World!</p>")
+/// # ;
+/// ```
+#[derive(Debug, Clone, PartialEq, Hash)]
+pub struct Html(String);
+
+impl Html {
+    /// Constructs a new `Html` responder.
+    pub fn new(html: impl Into<String>) -> Self {
+        Self(html.into())
+    }
+}
+
+impl Responder for Html {
+    type Body = String;
+
+    fn respond_to(self, _req: &HttpRequest) -> HttpResponse<Self::Body> {
+        let mut res = HttpResponse::with_body(StatusCode::OK, self.0);
+        res.headers_mut().insert(
+            header::CONTENT_TYPE,
+            ContentType::html().try_into_value().unwrap(),
+        );
+        res
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test::TestRequest;
+
+    #[test]
+    fn responder() {
+        let req = TestRequest::default().to_http_request();
+
+        let res = Html::new("<p>Hello, World!</p>");
+        let res = res.respond_to(&req);
+
+        assert!(res.status().is_success());
+        assert!(res
+            .headers()
+            .get(header::CONTENT_TYPE)
+            .unwrap()
+            .to_str()
+            .unwrap()
+            .starts_with("text/html"));
+        assert!(res.body().starts_with("<p>"));
+    }
+}

actix-web/src/types/mod.rs

@@ -3,6 +3,7 @@
 mod either;
 mod form;
 mod header;
+mod html;
 mod json;
 mod path;
 mod payload;
@@ -13,6 +14,7 @@ pub use self::{
     either::Either,
     form::{Form, FormConfig, UrlEncoded},
     header::Header,
+    html::Html,
     json::{Json, JsonBody, JsonConfig},
     path::{Path, PathConfig},
     payload::{Payload, PayloadConfig},