From d2c27256891c3576b7c7b1cedbca8953615610f8 Mon Sep 17 00:00:00 2001
From: Sergio Benitez <sb@sergio.bz>
Date: Wed, 9 Jun 2021 17:07:26 -0700
Subject: [PATCH] Implement 'De(Serialize)' for 'Method'.

---
 core/http/src/method.rs                       | 58 ++++++++++++++++++-
 .../{http_uri_serde.rs => http_serde.rs}      | 37 ++++++++++++
 2 files changed, 94 insertions(+), 1 deletion(-)
 rename core/lib/tests/{http_uri_serde.rs => http_serde.rs} (81%)

diff --git a/core/http/src/method.rs b/core/http/src/method.rs
index ecb06123..7fdf8b29 100644
--- a/core/http/src/method.rs
+++ b/core/http/src/method.rs
@@ -3,9 +3,30 @@ use std::str::FromStr;
 
 use self::Method::*;
 
-// TODO: Support non-standard methods, here and in codegen.
+// TODO: Support non-standard methods, here and in codegen?
 
 /// Representation of HTTP methods.
+///
+/// # (De)serialization
+///
+/// `Method` is both `Serialize` and `Deserialize`, represented as an
+/// [uncased](crate::uncased) string. For example, [`Method::Get`] serializes to
+/// `"GET"` and deserializes from any casing of `"GET"` including `"get"`,
+/// `"GeT"`, and `"GET"`.
+///
+/// ```rust
+/// # #[cfg(feature = "serde")] mod serde {
+/// # use serde_ as serde;
+/// use serde::{Serialize, Deserialize};
+/// use rocket::http::Method;
+///
+/// #[derive(Deserialize, Serialize)]
+/// # #[serde(crate = "serde_")]
+/// struct Foo {
+///     method: Method,
+/// }
+/// # }
+/// ```
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
 pub enum Method {
     /// The `GET` variant.
@@ -127,3 +148,38 @@ impl fmt::Display for Method {
         self.as_str().fmt(f)
     }
 }
+
+#[cfg(feature = "serde")]
+mod serde {
+    use std::fmt;
+    use super::*;
+
+    use serde_::ser::{Serialize, Serializer};
+    use serde_::de::{Deserialize, Deserializer, Error, Visitor, Unexpected};
+
+    impl<'a> Serialize for Method {
+        fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+            serializer.serialize_str(self.as_str())
+        }
+    }
+
+    struct DeVisitor;
+
+    impl<'de> Visitor<'de> for DeVisitor {
+        type Value = Method;
+
+        fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+            write!(formatter, "valid HTTP method string")
+        }
+
+        fn visit_str<E: Error>(self, v: &str) -> Result<Self::Value, E> {
+            Method::from_str(v).map_err(|_| E::invalid_value(Unexpected::Str(v), &self))
+        }
+    }
+
+    impl<'de> Deserialize<'de> for Method {
+        fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+            deserializer.deserialize_str(DeVisitor)
+        }
+    }
+}
diff --git a/core/lib/tests/http_uri_serde.rs b/core/lib/tests/http_serde.rs
similarity index 81%
rename from core/lib/tests/http_uri_serde.rs
rename to core/lib/tests/http_serde.rs
index 35e22405..7215ec83 100644
--- a/core/lib/tests/http_uri_serde.rs
+++ b/core/lib/tests/http_serde.rs
@@ -4,6 +4,7 @@ use pretty_assertions::assert_eq;
 
 use rocket::{Config, uri};
 use rocket::http::uri::{Absolute, Asterisk, Authority, Origin, Reference};
+use rocket::http::Method;
 
 #[derive(PartialEq, Debug, Serialize, Deserialize)]
 struct UriContainer<'a> {
@@ -23,6 +24,13 @@ struct UriContainerOwned {
     reference: Reference<'static>,
 }
 
+#[derive(PartialEq, Debug, Serialize, Deserialize)]
+struct MethodContainer {
+    mget: Method,
+    mput: Method,
+    mpost: Method,
+}
+
 #[test]
 fn uri_serde() {
     figment::Jail::expect_with(|jail| {
@@ -111,3 +119,32 @@ fn uri_serde_round_trip() {
         reference: uri!("https://rocket.rs:8000/index.html").into(),
     });
 }
+
+#[test]
+fn method_serde() {
+    figment::Jail::expect_with(|jail| {
+        jail.create_file("Rocket.toml", r#"
+            [default]
+            mget = "GET"
+            mput = "PuT"
+            mpost = "post"
+        "#)?;
+
+        let methods: MethodContainer = Config::figment().extract()?;
+        assert_eq!(methods, MethodContainer {
+            mget: Method::Get,
+            mput: Method::Put,
+            mpost: Method::Post
+        });
+
+        let tmp = Figment::from(Serialized::defaults(methods));
+        let methods: MethodContainer = tmp.extract()?;
+        assert_eq!(methods, MethodContainer {
+            mget: Method::Get,
+            mput: Method::Put,
+            mpost: Method::Post
+        });
+
+        Ok(())
+    });
+}