ws protocol: make tungstenite integration optional feature

crates/ws_protocol/Cargo.toml

@@ -12,6 +12,10 @@ rust-version.workspace = true
 
 readme = "./README.md"
 
+[features]
+default = ["tungstenite"]
+tungstenite = ["dep:tungstenite"]
+
 [lib]
 name = "aquatic_ws_protocol"
 
@@ -26,7 +30,7 @@ hashbrown = { version = "0.14", features = ["serde"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 simd-json = "0.13"
-tungstenite = "0.21"
+tungstenite = { version = "0.21", optional = true }
 
 [dev-dependencies]
 criterion = "0.5"

crates/ws_protocol/src/incoming/mod.rs

@@ -15,6 +15,7 @@ pub enum InMessage {
     ScrapeRequest(ScrapeRequest),
 }
 
+#[cfg(feature = "tungstenite")]
 impl InMessage {
     #[inline]
     pub fn to_ws_message(&self) -> ::tungstenite::Message {

crates/ws_protocol/src/lib.rs

@@ -227,6 +227,7 @@ mod tests {
         }
     }
 
+    #[cfg(feature = "tungstenite")]
     #[quickcheck]
     fn quickcheck_serde_identity_in_message(in_message_1: InMessage) -> bool {
         let ws_message = in_message_1.to_ws_message();
@@ -246,6 +247,7 @@ mod tests {
         success
     }
 
+    #[cfg(feature = "tungstenite")]
     #[quickcheck]
     fn quickcheck_serde_identity_out_message(out_message_1: OutMessage) -> bool {
         let ws_message = out_message_1.to_ws_message();

crates/ws_protocol/src/outgoing/mod.rs

@@ -23,6 +23,7 @@ pub enum OutMessage {
     ErrorResponse(ErrorResponse),
 }
 
+#[cfg(feature = "tungstenite")]
 impl OutMessage {
     #[inline]
     pub fn to_ws_message(&self) -> tungstenite::Message {