From 4ce2d3a80f733c7eabe5efba8ff888fa8e846cbc Mon Sep 17 00:00:00 2001
From: Filip Tibell <filip.tibell@gmail.com>
Date: Thu, 24 Apr 2025 21:15:46 +0200
Subject: [PATCH] Make runtime return values into a non exhaustive struct to
 prevent future breakage

---
 crates/lune/src/cli/run.rs        |  2 +-
 crates/lune/src/lib.rs            |  2 +-
 crates/lune/src/rt/mod.rs         |  2 +-
 crates/lune/src/rt/runtime.rs     | 55 ++++++++++++++++++++++++++-----
 crates/lune/src/standalone/mod.rs |  2 +-
 crates/lune/src/tests.rs          |  4 +--
 6 files changed, 53 insertions(+), 14 deletions(-)

diff --git a/crates/lune/src/cli/run.rs b/crates/lune/src/cli/run.rs
index 65df5ed..f86f324 100644
--- a/crates/lune/src/cli/run.rs
+++ b/crates/lune/src/cli/run.rs
@@ -57,7 +57,7 @@ impl RunCommand {
                 eprintln!("{err}");
                 ExitCode::FAILURE
             }
-            Ok((code, _)) => ExitCode::from(code),
+            Ok(values) => ExitCode::from(values.status()),
         })
     }
 }
diff --git a/crates/lune/src/lib.rs b/crates/lune/src/lib.rs
index a0fb8bf..76bbd83 100644
--- a/crates/lune/src/lib.rs
+++ b/crates/lune/src/lib.rs
@@ -5,4 +5,4 @@ mod rt;
 #[cfg(test)]
 mod tests;
 
-pub use crate::rt::{Runtime, RuntimeError, RuntimeResult};
+pub use crate::rt::{Runtime, RuntimeError, RuntimeResult, RuntimeReturnValues};
diff --git a/crates/lune/src/rt/mod.rs b/crates/lune/src/rt/mod.rs
index 16393f1..6e95268 100644
--- a/crates/lune/src/rt/mod.rs
+++ b/crates/lune/src/rt/mod.rs
@@ -2,4 +2,4 @@ mod result;
 mod runtime;
 
 pub use self::result::{RuntimeError, RuntimeResult};
-pub use self::runtime::Runtime;
+pub use self::runtime::{Runtime, RuntimeReturnValues};
diff --git a/crates/lune/src/rt/runtime.rs b/crates/lune/src/rt/runtime.rs
index 3a05243..7c45355 100644
--- a/crates/lune/src/rt/runtime.rs
+++ b/crates/lune/src/rt/runtime.rs
@@ -11,6 +11,46 @@ use mlua_luau_scheduler::{Functions, Scheduler};
 
 use super::{RuntimeError, RuntimeResult};
 
+/**
+    Values returned by running a Lune runtime until completion.
+*/
+#[non_exhaustive]
+pub struct RuntimeReturnValues {
+    /// The exit code manually returned from the runtime, if any.
+    pub code: Option<u8>,
+    /// Whether any errors were thrown from threads
+    /// that were not the main thread, or not.
+    pub errored: bool,
+    /// The final values returned by the main thread.
+    pub values: LuaMultiValue,
+}
+
+impl RuntimeReturnValues {
+    /**
+        Returns the final, combined "status" of the runtime return values.
+
+        If no exit code was explicitly set by either the main thread,
+        or any threads it may have spawned, the status will be either:
+
+        - `0` if no threads errored
+        - `1` if any threads errored
+    */
+    #[must_use]
+    pub fn status(&self) -> u8 {
+        self.code.unwrap_or(u8::from(self.errored))
+    }
+
+    /**
+        Returns whether the run was considered successful, or not.
+
+        See [`RuntimeReturnValues::status`] for more information.
+    */
+    #[must_use]
+    pub fn success(&self) -> bool {
+        self.status() == 0
+    }
+}
+
 /**
     A Lune runtime.
 */
@@ -125,7 +165,7 @@ impl Runtime {
         &mut self,
         script_name: impl AsRef<str>,
         script_contents: impl AsRef<[u8]>,
-    ) -> RuntimeResult<(u8, Vec<LuaValue>)> {
+    ) -> RuntimeResult<RuntimeReturnValues> {
         // Add error callback to format errors nicely + store status
         let got_any_error = Arc::new(AtomicBool::new(false));
         let got_any_inner = Arc::clone(&got_any_error);
@@ -148,16 +188,15 @@ impl Runtime {
         let main_thread_id = self.sched.push_thread_back(main, ())?;
         self.sched.run().await;
 
-        let main_thread_res = match self.sched.get_thread_result(main_thread_id) {
+        let main_thread_values = match self.sched.get_thread_result(main_thread_id) {
             Some(res) => res,
             None => LuaValue::Nil.into_lua_multi(&self.lua),
         }?;
 
-        Ok((
-            self.sched
-                .get_exit_code()
-                .unwrap_or(u8::from(got_any_error.load(Ordering::SeqCst))),
-            main_thread_res.into_vec(),
-        ))
+        Ok(RuntimeReturnValues {
+            code: self.sched.get_exit_code(),
+            errored: got_any_error.load(Ordering::SeqCst),
+            values: main_thread_values,
+        })
     }
 }
diff --git a/crates/lune/src/standalone/mod.rs b/crates/lune/src/standalone/mod.rs
index 2bbc7c0..6f0c0d2 100644
--- a/crates/lune/src/standalone/mod.rs
+++ b/crates/lune/src/standalone/mod.rs
@@ -38,6 +38,6 @@ pub async fn run(patched_bin: impl AsRef<[u8]>) -> Result<ExitCode> {
             eprintln!("{err}");
             ExitCode::FAILURE
         }
-        Ok((code, _)) => ExitCode::from(code),
+        Ok(values) => ExitCode::from(values.status()),
     })
 }
diff --git a/crates/lune/src/tests.rs b/crates/lune/src/tests.rs
index e9ff03b..e4809e8 100644
--- a/crates/lune/src/tests.rs
+++ b/crates/lune/src/tests.rs
@@ -44,8 +44,8 @@ macro_rules! create_tests {
 				.trim_end_matches(".luau")
 				.trim_end_matches(".lua")
 				.to_string();
-            let (exit_code, _) = lune.run(&script_name, &script).await?;
-            Ok(ExitCode::from(exit_code))
+            let script_values = lune.run(&script_name, &script).await?;
+            Ok(ExitCode::from(script_values.status()))
         }
     )* }
 }