[ty] Fix server version (#19284)

crates/ruff_db/src/lib.rs

@@ -28,6 +28,21 @@ pub use web_time::{Instant, SystemTime, SystemTimeError};
 pub type FxDashMap<K, V> = dashmap::DashMap<K, V, BuildHasherDefault<FxHasher>>;
 pub type FxDashSet<K> = dashmap::DashSet<K, BuildHasherDefault<FxHasher>>;
 
+static VERSION: std::sync::OnceLock<String> = std::sync::OnceLock::new();
+
+/// Returns the version of the executing program if set.
+pub fn program_version() -> Option<&'static str> {
+    VERSION.get().map(|version| version.as_str())
+}
+
+/// Sets the version of the executing program.
+///
+/// ## Errors
+/// If the version has already been initialized (can only be set once).
+pub fn set_program_version(version: String) -> Result<(), String> {
+    VERSION.set(version)
+}
+
 /// Most basic database that gives access to files, the host system, source code, and parsed AST.
 #[salsa::db]
 pub trait Db: salsa::Database {