Added tracebacks in tests

Author: sebimoe

p8rs-piccolo/src/thread/mod.rs

@@ -5,6 +5,7 @@ mod vm;
 use gc_arena::{Collect, DynamicRootSet, Mutation};
 use thiserror::Error;
 use alloc::vec::Vec;
+use core::fmt::{Display, Formatter};
 use crate::compiler::LineNumber;
 use crate::meta_ops::{MetaCallError, MetaOperatorError};
 use crate::StashedString;
@@ -61,6 +62,20 @@ pub type StashedTraceback = TracebackBase<StashedString>;
 pub type Traceback<'gc> = TracebackBase<crate::String<'gc>>;
 pub type ExternTraceback = TracebackBase<alloc::string::String>;
 
+impl<S> Display for TracebackBase<S>
+where S: Display {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
+        for entry in self.entries.iter() {
+            write!(f, "line {}", entry.line_number)?;
+            if let Some(name) = &entry.name {
+                write!(f, " in function '{}'", name)?;
+            }
+            write!(f, "\n")?;
+        }
+        Ok(())
+    }
+}
+
 impl<S> TracebackBase<S>
 {
     pub fn into_traceback<D>(self) -> TracebackBase<D>

p8rs-tests/src/runner/p8rs.rs

@@ -3,7 +3,7 @@ use std::path::Path;
 use std::rc::Rc;
 use std::thread;
 use std::time::{Duration, Instant};
-use p8rs::vm;
+use p8rs::{vm, ExternError};
 use p8rs_types::p8scii;
 
 use crate::runner::{Log, RunResult, TIMEOUT_MS};
@@ -55,7 +55,15 @@ pub fn run(source: &[u8], log_file: impl AsRef<Path>) -> RunResult {
 
 	if let Some(err) = result.as_ref().err() {
 		println!("-- p8rs error --");
-		println!("{err}");
+		match err {
+			ExternError::Lua(err) => println!("{err}"),
+			ExternError::Runtime(runtime_err) => {
+				println!("{err}");
+				if let Some(Ok(traceback)) = runtime_err.1.as_ref().map(|tb| vm.get_traceback(tb)) {
+					println!("traceback:\n{traceback}");
+				}
+			}
+		}
 	}
 
 	if timeout {

p8rs/src/lib.rs

@@ -9,6 +9,8 @@
 extern crate alloc;
 extern crate core;
 
+pub use p8rs_piccolo::error::ExternError;
+
 pub mod rle;
 pub mod vm;
 pub mod colors;

p8rs/src/vm/mod.rs

@@ -21,6 +21,8 @@ pub use runtime::Runtime;
 pub use callbacks::Callbacks;
 use api::install_pico8_apis;
 use cart::CartLoadError;
+use p8rs_piccolo::stash::Fetchable;
+use p8rs_piccolo::thread::{ExternTraceback, StashedTraceback, Traceback};
 use traceback::write_traceback_entries;
 
 #[derive(Debug, Clone, Copy, Ord, PartialOrd, Eq, PartialEq, Hash)]
@@ -187,6 +189,10 @@ impl<A: Allocator + 'static> P8rs<A> {
 	pub fn runtime(&mut self) -> &mut Runtime<A> {
 		&mut self.runtime
 	}
+	
+	pub fn get_traceback(&mut self, stashed: &StashedTraceback) -> Result<ExternTraceback, ExternError> {
+		self.lua.try_enter(|ctx| Ok(ctx.fetch(stashed).into_traceback()))
+	}
 }