tower_lsp_f/
jsonrpc.rs

1//! A subset of JSON-RPC types used by the Language Server Protocol.
2
3pub(crate) use self::error::not_initialized_error;
4pub use self::error::{Error, ErrorCode, Result};
5pub use self::request::{Request, RequestBuilder};
6pub use self::response::Response;
7pub(crate) use self::router::Router;
8pub use self::router::{FromParams, IntoResponse, Method};
9
10use std::borrow::Cow;
11use std::fmt::{self, Debug, Display, Formatter};
12
13use lsp_types::NumberOrString;
14use serde::de::{self, Deserializer};
15use serde::ser::Serializer;
16use serde::{Deserialize, Serialize};
17
18mod error;
19mod request;
20mod response;
21mod router;
22
23/// A unique ID used to correlate requests and responses together.
24#[derive(Clone, Debug, Eq, Hash, PartialEq, Deserialize, Serialize)]
25#[serde(untagged)]
26#[derive(Default)]
27pub enum Id {
28    /// Numeric ID.
29    Number(i64),
30    /// String ID.
31    String(String),
32    /// Null ID.
33    ///
34    /// While `null` is considered a valid request ID by the JSON-RPC 2.0 specification, its use is
35    /// _strongly_ discouraged because the specification also uses a `null` value to indicate an
36    /// unknown ID in the [`Response`] object.
37    #[default]
38    Null,
39}
40
41impl Display for Id {
42    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
43        match self {
44            Id::Number(id) => Display::fmt(id, f),
45            Id::String(id) => Debug::fmt(id, f),
46            Id::Null => f.write_str("null"),
47        }
48    }
49}
50
51impl From<i64> for Id {
52    fn from(n: i64) -> Self {
53        Id::Number(n)
54    }
55}
56
57impl From<&'_ str> for Id {
58    fn from(s: &'_ str) -> Self {
59        Id::String(s.to_string())
60    }
61}
62
63impl From<String> for Id {
64    fn from(s: String) -> Self {
65        Id::String(s)
66    }
67}
68
69impl From<NumberOrString> for Id {
70    fn from(num_or_str: NumberOrString) -> Self {
71        match num_or_str {
72            NumberOrString::Number(num) => Id::Number(num as i64),
73            NumberOrString::String(s) => Id::String(s),
74        }
75    }
76}
77
78#[derive(Clone, Debug, PartialEq)]
79struct Version;
80
81impl<'de> Deserialize<'de> for Version {
82    fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
83    where
84        D: Deserializer<'de>,
85    {
86        #[derive(Deserialize)]
87        struct Inner<'a>(#[serde(borrow)] Cow<'a, str>);
88
89        let Inner(ver) = Inner::deserialize(deserializer)?;
90
91        match ver.as_ref() {
92            "2.0" => Ok(Version),
93            _ => Err(de::Error::custom("expected JSON-RPC version \"2.0\"")),
94        }
95    }
96}
97
98impl Serialize for Version {
99    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
100    where
101        S: Serializer,
102    {
103        serializer.serialize_str("2.0")
104    }
105}
106
107/// An incoming or outgoing JSON-RPC message.
108#[derive(Deserialize, Serialize)]
109#[cfg_attr(test, derive(Debug, PartialEq))]
110#[serde(untagged)]
111pub(crate) enum Message {
112    /// A response message.
113    Response(Response),
114    /// A request or notification message.
115    Request(Request),
116}
117
118#[cfg(test)]
119mod tests {
120    use serde_json::json;
121
122    use super::*;
123
124    #[test]
125    fn incoming_from_str_or_value() {
126        let v = json!({"jsonrpc":"2.0","method":"initialize","params":{"capabilities":{}},"id":0});
127        let from_str: Message = serde_json::from_str(&v.to_string()).unwrap();
128        let from_value: Message = serde_json::from_value(v).unwrap();
129        assert_eq!(from_str, from_value);
130    }
131
132    #[test]
133    fn outgoing_from_str_or_value() {
134        let v = json!({"jsonrpc":"2.0","result":{},"id":1});
135        let from_str: Message = serde_json::from_str(&v.to_string()).unwrap();
136        let from_value: Message = serde_json::from_value(v).unwrap();
137        assert_eq!(from_str, from_value);
138    }
139
140    #[test]
141    fn parses_incoming_message() {
142        let server_request =
143            json!({"jsonrpc":"2.0","method":"initialize","params":{"capabilities":{}},"id":0});
144        let incoming = serde_json::from_value(server_request).unwrap();
145        assert!(matches!(incoming, Message::Request(_)));
146
147        let server_notif = json!({"jsonrpc":"2.0","method":"initialized","params":{}});
148        let incoming = serde_json::from_value(server_notif).unwrap();
149        assert!(matches!(incoming, Message::Request(_)));
150
151        let client_request = json!({"jsonrpc":"2.0","id":0,"result":[null]});
152        let incoming = serde_json::from_value(client_request).unwrap();
153        assert!(matches!(incoming, Message::Response(_)));
154    }
155
156    #[test]
157    fn parses_outgoing_message() {
158        let client_request = json!({"jsonrpc":"2.0","method":"workspace/configuration","params":{"scopeUri":null,"section":"foo"},"id":0});
159        let outgoing = serde_json::from_value(client_request).unwrap();
160        assert!(matches!(outgoing, Message::Request(_)));
161
162        let client_notif = json!({"jsonrpc":"2.0","method":"window/logMessage","params":{"message":"foo","type":0}});
163        let outgoing = serde_json::from_value(client_notif).unwrap();
164        assert!(matches!(outgoing, Message::Request(_)));
165
166        let server_response = json!({"jsonrpc":"2.0","id":0,"result":[null]});
167        let outgoing = serde_json::from_value(server_response).unwrap();
168        assert!(matches!(outgoing, Message::Response(_)));
169    }
170
171    #[test]
172    fn parses_invalid_server_request() {
173        let unknown_method = json!({"jsonrpc":"2.0","method":"foo"});
174        let incoming = serde_json::from_value(unknown_method).unwrap();
175        assert!(matches!(incoming, Message::Request(_)));
176
177        let unknown_method_with_id = json!({"jsonrpc":"2.0","method":"foo","id":0});
178        let incoming = serde_json::from_value(unknown_method_with_id).unwrap();
179        assert!(matches!(incoming, Message::Request(_)));
180
181        let missing_method = json!({"jsonrpc":"2.0"});
182        let incoming = serde_json::from_value(missing_method).unwrap();
183        assert!(matches!(incoming, Message::Request(_)));
184
185        let missing_method_with_id = json!({"jsonrpc":"2.0","id":0});
186        let incoming = serde_json::from_value(missing_method_with_id).unwrap();
187        assert!(matches!(incoming, Message::Request(_)));
188    }
189
190    #[test]
191    fn accepts_null_request_id() {
192        let request_id: Id = serde_json::from_value(json!(null)).unwrap();
193        assert_eq!(request_id, Id::Null);
194    }
195
196    #[test]
197    fn accepts_negative_integer_request_id() {
198        let request_id: Id = serde_json::from_value(json!(-1)).unwrap();
199        assert_eq!(request_id, Id::Number(-1));
200    }
201}