feat: complete wgcloak v1 transports

tests/server_capabilities.rs

@@ -0,0 +1,50 @@
+use wgcloak::config::{Config, ServerConfig, MAX_APPLICATION_DATAGRAM_SIZE};
+
+const SECRET: &str = "MDEyMzQ1Njc4OWFiY2RlZjAxMjM0NTY3ODlhYmNkZWY=";
+
+fn server_text(max_datagram_size: Option<u16>) -> String {
+    let network = max_datagram_size
+        .map(|value| format!("[network]\nmax_datagram_size = {value}\n"))
+        .unwrap_or_default();
+    format!(
+        "[server]\nlisten = \"::1\"\n[backend]\ntarget = \"127.0.0.1:51820\"\n{network}[transports.direct_udp]\nport = 51830\n[[auth.clients]]\nid = \"test\"\nsecret = \"{SECRET}\"\n"
+    )
+}
+
+#[test]
+fn server_datagram_capability_defaults_and_accepts_boundary() {
+    let Config::Server(defaults) = Config::from_str(&server_text(None)).unwrap() else {
+        panic!("expected server configuration");
+    };
+    assert_eq!(defaults.network.max_datagram_size, 1200);
+
+    let Config::Server(config) =
+        Config::from_str(&server_text(Some(MAX_APPLICATION_DATAGRAM_SIZE))).unwrap()
+    else {
+        panic!("expected server configuration");
+    };
+    config.validate().unwrap();
+    assert_eq!(
+        config.network.max_datagram_size,
+        MAX_APPLICATION_DATAGRAM_SIZE
+    );
+}
+
+#[test]
+fn server_datagram_capability_rejects_unsupported_size() {
+    let Config::Server(config) =
+        Config::from_str(&server_text(Some(MAX_APPLICATION_DATAGRAM_SIZE + 1))).unwrap()
+    else {
+        panic!("expected server configuration");
+    };
+    let error = config.validate().unwrap_err().to_string();
+    assert!(error.contains("network.max_datagram_size"));
+}
+
+#[test]
+fn server_config_type_remains_constructible_from_toml() {
+    let Config::Server(config): Config = Config::from_str(&server_text(Some(1400))).unwrap() else {
+        panic!("expected server configuration");
+    };
+    let _: ServerConfig = config;
+}