Add support for the HTTP DELETE method

Add a Delete variant to the Method enum to support DELETE requests.
Reject DELETE requests with a body (same as GET requests).

Signed-off-by: Ilias Stamatis <ilstam@amazon.com>

src/common/mod.rs

@@ -244,6 +244,8 @@ pub enum Method {
     Put,
     /// PATCH Method.
     Patch,
+    /// DELETE Method.
+    Delete,
 }
 
 impl Method {
@@ -259,6 +261,7 @@ impl Method {
             b"GET" => Ok(Self::Get),
             b"PUT" => Ok(Self::Put),
             b"PATCH" => Ok(Self::Patch),
+            b"DELETE" => Ok(Self::Delete),
             _ => Err(RequestError::InvalidHttpMethod("Unsupported HTTP method.")),
         }
     }
@@ -269,6 +272,7 @@ impl Method {
             Self::Get => b"GET",
             Self::Put => b"PUT",
             Self::Patch => b"PATCH",
+            Self::Delete => b"DELETE",
         }
     }
 
@@ -278,6 +282,7 @@ impl Method {
             Method::Get => "GET",
             Method::Put => "PUT",
             Method::Patch => "PATCH",
+            Method::Delete => "DELETE",
         }
     }
 }
@@ -398,11 +403,13 @@ mod tests {
         assert_eq!(Method::Get.raw(), b"GET");
         assert_eq!(Method::Put.raw(), b"PUT");
         assert_eq!(Method::Patch.raw(), b"PATCH");
+        assert_eq!(Method::Delete.raw(), b"DELETE");
 
         // Tests for try_from
         assert_eq!(Method::try_from(b"GET").unwrap(), Method::Get);
         assert_eq!(Method::try_from(b"PUT").unwrap(), Method::Put);
         assert_eq!(Method::try_from(b"PATCH").unwrap(), Method::Patch);
+        assert_eq!(Method::try_from(b"DELETE").unwrap(), Method::Delete);
         assert_eq!(
             Method::try_from(b"POST").unwrap_err(),
             RequestError::InvalidHttpMethod("Unsupported HTTP method.")
@@ -587,5 +594,8 @@ mod tests {
 
         let val = Method::Patch;
         assert_eq!(val.to_str(), "PATCH");
+
+        let val = Method::Delete;
+        assert_eq!(val.to_str(), "DELETE");
     }
 }

src/request.rs

@@ -249,7 +249,9 @@ impl Request {
                         None
                     }
                     content_length => {
-                        if request_line.method == Method::Get {
+                        if request_line.method == Method::Get
+                            || request_line.method == Method::Delete
+                        {
                             return Err(RequestError::InvalidRequest);
                         }
                         // Multiplication is safe because `CRLF_LEN` is a small constant.
@@ -483,6 +485,15 @@ mod tests {
             RequestError::InvalidRequest
         );
 
+        // Test for invalid Request (`DELETE` requests should have no body).
+        let request_bytes = b"DELETE /machine-config HTTP/1.1\r\n\
+                                        Content-Length: 13\r\n\
+                                        Content-Type: application/json\r\n\r\nwhatever body";
+        assert_eq!(
+            Request::try_from(request_bytes, None).unwrap_err(),
+            RequestError::InvalidRequest
+        );
+
         // Test for request larger than maximum len provided.
         let request_bytes = b"GET http://localhost/home HTTP/1.0\r\n\
                                      Last-Modified: Tue, 15 Nov 1994 12:45:26 GMT\r\n\r\n";