add "unstable" feature

Cargo.toml

@@ -21,6 +21,7 @@ thiserror = "1.0.31"
 [features]
 default = []
 builder = ["derive_builder"]
+unstable = []
 
 [package.metadata.cargo_metadata_test]
 some_field = true

src/lib.rs

@@ -99,6 +99,7 @@ pub use dependency::DependencyBuilder;
 pub use dependency::{Dependency, DependencyKind};
 use diagnostic::Diagnostic;
 pub use errors::{Error, Result};
+#[cfg(feature = "unstable")]
 pub use libtest::TestMessage;
 #[allow(deprecated)]
 pub use messages::parse_messages;
@@ -116,6 +117,7 @@ use serde::{Deserialize, Deserializer, Serialize};
 mod dependency;
 pub mod diagnostic;
 mod errors;
+#[cfg(feature = "unstable")]
 pub mod libtest;
 mod messages;
 

src/libtest.rs

@@ -1,4 +1,6 @@
-//! parses output of <https://github.com/rust-lang/rust/blob/master/library/test/src/formatters/json.rs>.
+//! Parses output of [libtest](https://github.com/rust-lang/rust/blob/master/library/test/src/formatters/json.rs).
+//!
+//! As this module parses output of a unstable format, all structs in this module are volatile.
 use serde::{Deserialize, Serialize};
 
 /// Suite related event
@@ -106,16 +108,6 @@ impl TestEvent {
             _ => None,
         }
     }
-
-    /// If this test is in progress.
-    pub fn in_progress(&self) -> bool {
-        matches!(self, Self::Started { .. })
-    }
-
-    /// If this test has finished
-    pub fn is_finished(&self) -> bool {
-        !self.in_progress()
-    }
 }
 
 #[derive(Debug, PartialEq, Deserialize, Serialize)]