From 436f99e6b8d2a8c943489e5c98ffd7942664e99a Mon Sep 17 00:00:00 2001
From: Waffle <waffle.lapkin@gmail.com>
Date: Fri, 27 Dec 2019 17:35:39 +0300
Subject: [PATCH 1/2] Replace `KeyboardButton`'s optional mutually exclusive
 fields by an enum

---
 src/types/keyboard_button.rs | 132 +++++++++++++++++++++++++++++++++--
 1 file changed, 127 insertions(+), 5 deletions(-)

diff --git a/src/types/keyboard_button.rs b/src/types/keyboard_button.rs
index 01929838..2176eb87 100644
--- a/src/types/keyboard_button.rs
+++ b/src/types/keyboard_button.rs
@@ -1,19 +1,141 @@
+use serde::{de::Error, Deserialize, Deserializer, Serialize, Serializer};
+
+use crate::types::True;
+
 /// This object represents one button of the reply keyboard. For filter text
 /// buttons String can be used instead of this object to specify text of the
-/// button. Optional fields are mutually exclusive.
+/// button.
+#[serde_with_macros::skip_serializing_none]
 #[derive(Debug, Serialize, Deserialize, Hash, PartialEq, Eq, Clone)]
 pub struct KeyboardButton {
     /// Text of the button. If none of the optional fields are used, it will
     /// be sent as a message when the button is pressed
     pub text: String,
 
-    #[serde(skip_serializing_if = "Option::is_none")]
+    /// Request something from user.
+    /// - If `Some(Contact)`, the user's phone number will be sent as a contact
+    ///   when the button is pressed. Available in private chats only
+    /// - If `Some(Location)`, the user's current location will be sent when
+    ///   the button is pressed. Available in private chats only
+    #[serde(flatten)]
+    pub request: Option<ButtonRequest>,
+}
+
+// Serialize + Deserialize are implemented by hand
+#[derive(Debug, Hash, PartialEq, Eq, Clone)]
+pub enum ButtonRequest {
+    Location,
+    Contact,
+}
+
+/// Helper struct for (de)serializing [`ButtonRequest`](ButtonRequest)
+#[serde_with_macros::skip_serializing_none]
+#[derive(Serialize, Deserialize)]
+struct RawRequest {
     /// Optional. If True, the user's phone number will be sent as a contact
     /// when the button is pressed. Available in private chats only
-    pub request_contact: Option<bool>,
+    #[serde(rename = "request_contact")]
+    contact: Option<True>,
 
-    #[serde(skip_serializing_if = "Option::is_none")]
     /// Optional. If True, the user's current location will be sent when the
     /// button is pressed. Available in private chats only
-    pub request_location: Option<bool>,
+    #[serde(rename = "request_location")]
+    location: Option<True>,
+}
+
+impl<'de> Deserialize<'de> for ButtonRequest {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let raw = RawRequest::deserialize(deserializer)?;
+        match raw {
+            RawRequest {
+                contact: Some(_),
+                location: Some(_),
+            } => Err(D::Error::custom(
+                "`request_contact` and `request_location` fields are mutually \
+                 exclusive, but both were provided",
+            )),
+            RawRequest {
+                contact: Some(_), ..
+            } => Ok(Self::Contact),
+            RawRequest {
+                location: Some(_), ..
+            } => Ok(Self::Location),
+            _ => Err(D::Error::custom(
+                "Either one of `request_contact` and `request_location` \
+                 fields is required",
+            )),
+        }
+    }
+}
+
+impl Serialize for ButtonRequest {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        match self {
+            Self::Contact => RawRequest {
+                contact: Some(True),
+                location: None,
+            }
+            .serialize(serializer),
+            Self::Location => RawRequest {
+                contact: None,
+                location: Some(True),
+            }
+            .serialize(serializer),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn serialize_no_request() {
+        let button = KeyboardButton {
+            text: String::from(""),
+            request: None,
+        };
+        let expected = r#"{"text":""}"#;
+        let actual = serde_json::to_string(&button).unwrap();
+        assert_eq!(expected, actual);
+    }
+
+    #[test]
+    fn serialize_request_contact() {
+        let button = KeyboardButton {
+            text: String::from(""),
+            request: Some(ButtonRequest::Contact),
+        };
+        let expected = r#"{"text":"","request_contact":true}"#;
+        let actual = serde_json::to_string(&button).unwrap();
+        assert_eq!(expected, actual);
+    }
+
+    #[test]
+    fn deserialize_no_request() {
+        let json = r#"{"text":""}"#;
+        let expected = KeyboardButton {
+            text: String::from(""),
+            request: None,
+        };
+        let actual = serde_json::from_str(json).unwrap();
+        assert_eq!(expected, actual);
+    }
+
+    #[test]
+    fn deserialize_request_contact() {
+        let json = r#"{"text":"","request_contact":true}"#;
+        let expected = KeyboardButton {
+            text: String::from(""),
+            request: Some(ButtonRequest::Contact),
+        };
+        let actual = serde_json::from_str(json).unwrap();
+        assert_eq!(expected, actual);
+    }
 }

From 42b11f572e5c1689740cce082b4084ed81f517a7 Mon Sep 17 00:00:00 2001
From: Waffle <waffle.lapkin@gmail.com>
Date: Fri, 27 Dec 2019 17:48:00 +0300
Subject: [PATCH 2/2] Add `\n` to the end og the `keyboard_button.rs` file

---
 src/types/keyboard_button.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/types/keyboard_button.rs b/src/types/keyboard_button.rs
index 07f271c5..522a917e 100644
--- a/src/types/keyboard_button.rs
+++ b/src/types/keyboard_button.rs
@@ -140,4 +140,4 @@ mod tests {
         let actual = serde_json::from_str(json).unwrap();
         assert_eq!(expected, actual);
     }
-}
\ No newline at end of file
+}