fix(cli): handle recoverable errors gracefully and remove panics #4798

cli/src/debug/mod.rs

@@ -2,6 +2,7 @@
 #![allow(clippy::unnecessary_wraps)]
 
 use boa_engine::{Context, JsObject, js_string, object::ObjectInitializer, property::Attribute};
+use color_eyre::Result;
 
 mod function;
 mod gc;
@@ -67,13 +68,14 @@ fn create_boa_object(context: &mut Context) -> JsObject {
 }
 
 #[allow(clippy::redundant_pub_crate)]
-pub(crate) fn init_boa_debug_object(context: &mut Context) {
+pub(crate) fn init_boa_debug_object(context: &mut Context) -> Result<()> {
     let boa_object = create_boa_object(context);
     context
         .register_global_property(
             js_string!("$boa"),
             boa_object,
             Attribute::WRITABLE | Attribute::NON_ENUMERABLE | Attribute::CONFIGURABLE,
         )
-        .expect("cannot fail with the default object");
+        .map_err(|e| color_eyre::eyre::eyre!("failed to register debug object: {e}"))?;
+    Ok(())
 }

cli/src/helper.rs

@@ -140,12 +140,13 @@ static KEYWORDS: Set<&'static str> = phf_set! {
 };
 
 struct LineHighlighter {
-    regex: Regex,
+    regex: Option<Regex>,
 }
 
 impl LineHighlighter {
     fn new() -> Self {
-        // Precompiles the regex to avoid creating it again after every highlight
+        // Precompiles the regex to avoid creating it again after every highlight.
+        // If compilation fails (e.g. unsupported Unicode on some platforms), we fall back to no highlighting.
         let regex = Regex::new(
             r#"(?x)
             (?P<identifier>\b[$_\p{ID_Start}][$_\p{ID_Continue}\u{200C}\u{200D}]*\b) |
@@ -154,7 +155,7 @@ impl LineHighlighter {
             (?P<template_literal>`([^`\\]|\\.)*`) |
             (?P<op>[+\-/*%~^!&|=<>;:]) |
             (?P<number>0[bB][01](_?[01])*n?|0[oO][0-7](_?[0-7])*n?|0[xX][0-9a-fA-F](_?[0-9a-fA-F])*n?|(([0-9](_?[0-9])*\.([0-9](_?[0-9])*)?)|(([0-9](_?[0-9])*)?\.[0-9](_?[0-9])*)|([0-9](_?[0-9])*))([eE][+-]?[0-9](_?[0-9])*)?n?)"#,
-        ).expect("could not compile regular expression");
+        ).ok();
 
         Self { regex }
     }
@@ -200,12 +201,15 @@ impl Highlighter for LineHighlighter {
                 };
 
                 if let Some(colored) = colored {
-                    write!(dst, "{colored}").expect("could not append data to dst");
+                    let _ = write!(dst, "{colored}");
                 } else {
                     dst.push_str(&caps[0]);
                 }
             }
         }
-        self.regex.replace_all(line, Colorizer)
+        match &self.regex {
+            Some(regex) => regex.replace_all(line, Colorizer),
+            None => Borrowed(line),
+        }
     }
 }

cli/src/logger.rs

@@ -21,12 +21,12 @@ impl SharedExternalPrinterLogger {
     pub(crate) fn set<T: ExternalPrinter + Send + 'static>(&self, inner: T) {
         self.inner
             .lock()
-            .expect("printer lock failed")
+            .unwrap_or_else(|e| e.into_inner())
             .replace(Box::new(inner));
     }
 
     pub(crate) fn print(&self, message: String) {
-        if let Some(l) = &mut *self.inner.lock().expect("printer lock failed") {
+        if let Some(l) = &mut *self.inner.lock().unwrap_or_else(|e| e.into_inner()) {
             // Ignore errors, there's nothing we can do at this point.
             drop(l.print(message));
         } else {

cli/src/main.rs

@@ -303,9 +303,9 @@ fn dump<R: ReadChar>(src: Source<'_, R>, args: &Opt, context: &mut Context) -> R
                 let _timer = counters.new_timer("AST generation");
                 match arg {
                     DumpFormat::Json => serde_json::to_string(&module)
-                        .expect("could not convert AST to a JSON string"),
+                        .wrap_err("could not convert AST to a JSON string")?,
                     DumpFormat::JsonPretty => serde_json::to_string_pretty(&module)
-                        .expect("could not convert AST to a pretty JSON string"),
+                        .wrap_err("could not convert AST to a pretty JSON string")?,
                     DumpFormat::Debug => format!("{module:#?}"),
                 }
             } else {
@@ -324,9 +324,9 @@ fn dump<R: ReadChar>(src: Source<'_, R>, args: &Opt, context: &mut Context) -> R
                 let _timer = counters.new_timer("AST generation");
                 match arg {
                     DumpFormat::Json => serde_json::to_string(&script)
-                        .expect("could not convert AST to a JSON string"),
+                        .wrap_err("could not convert AST to a JSON string")?,
                     DumpFormat::JsonPretty => serde_json::to_string_pretty(&script)
-                        .expect("could not convert AST to a pretty JSON string"),
+                        .wrap_err("could not convert AST to a pretty JSON string")?,
                     DumpFormat::Debug => format!("{script:#?}"),
                 }
             };
@@ -431,13 +431,17 @@ fn evaluate_file(
     printer: &SharedExternalPrinterLogger,
 ) -> Result<()> {
     if args.has_dump_flag() {
-        return dump(Source::from_filepath(file)?, args, context);
+        return dump(
+            Source::from_filepath(file).wrap_err_with(|| format!("failed to read file '{}'", file.display()))?,
+            args,
+            context,
+        );
     }
 
     if let Some(flowgraph) = args.flowgraph {
         let flowgraph = generate_flowgraph(
             context,
-            Source::from_filepath(file)?,
+            Source::from_filepath(file).wrap_err_with(|| format!("failed to read file '{}'", file.display()))?,
             flowgraph.unwrap_or(FlowgraphFormat::Graphviz),
             args.flowgraph_direction,
         )?;
@@ -448,7 +452,8 @@ fn evaluate_file(
     }
 
     if args.module {
-        let source = Source::from_filepath(file)?;
+        let source = Source::from_filepath(file)
+            .wrap_err_with(|| format!("failed to read file '{}'", file.display()))?;
         let mut counters = Counters::new(args.time);
         let module = {
             let _timer = counters.new_timer("Parsing");
@@ -479,7 +484,8 @@ fn evaluate_file(
         };
     }
 
-    let source = Source::from_filepath(file)?;
+    let source = Source::from_filepath(file)
+        .wrap_err_with(|| format!("failed to read file '{}'", file.display()))?;
     let mut counters = Counters::new(args.time);
     let script = {
         let _timer = counters.new_timer("Parsing");
@@ -545,13 +551,13 @@ fn main() -> Result<()> {
     context.strict(args.strict);
 
     // Add `console`.
-    add_runtime(printer.clone(), &mut context);
+    add_runtime(printer.clone(), &mut context)?;
 
     // Trace Output
     context.set_trace(args.trace);
 
     if args.debug_object {
-        init_boa_debug_object(&mut context);
+        init_boa_debug_object(&mut context)?;
     }
 
     // Configure optimizer options
@@ -600,7 +606,9 @@ fn main() -> Result<()> {
         thread::sleep(Duration::from_millis(10));
     }
 
-    handle.join().expect("failed to join thread");
+    handle
+        .join()
+        .map_err(|_| eyre!("readline thread panicked"))?;
 
     Ok(())
 }
@@ -682,7 +690,7 @@ fn start_readline_thread(
 }
 
 /// Adds the CLI runtime to the context with default options.
-fn add_runtime(printer: SharedExternalPrinterLogger, context: &mut Context) {
+fn add_runtime(printer: SharedExternalPrinterLogger, context: &mut Context) -> Result<()> {
     boa_runtime::register(
         (
             boa_runtime::extensions::ConsoleExtension(printer),
@@ -694,7 +702,8 @@ fn add_runtime(printer: SharedExternalPrinterLogger, context: &mut Context) {
         None,
         context,
     )
-    .expect("should not fail while registering the runtime");
+    .map_err(|e| eyre!("failed to register runtime: {e}"))?;
+    Ok(())
 }
 
 #[allow(clippy::struct_field_names)]