[WIP] feat: Add native SourceMap support

bar.js

@@ -0,0 +1,6 @@
+"use strict";
+
+throw new Error("Hello world!");
+//# sourceMappingURL=bar.js.map
+
+asd;

core/error.rs

@@ -214,12 +214,14 @@ pub struct JsStackFrame {
 
 /// Applies source map to the given location
 fn apply_source_map<'a>(
+  scope: &mut v8::HandleScope,
   source_mapper: &mut crate::source_map::SourceMapper,
   file_name: Cow<'a, str>,
   line_number: i64,
   column_number: i64,
 ) -> (Cow<'a, str>, i64, i64) {
   match source_mapper.apply_source_map(
+    scope,
     &file_name,
     line_number as u32,
     column_number as u32,
@@ -357,7 +359,7 @@ impl JsStackFrame {
     ) {
       (Some(f), Some(l), Some(c)) => {
         let (file_name, line_num, col_num) =
-          apply_source_map(&mut source_mapper, f.into(), l, c);
+          apply_source_map(scope, &mut source_mapper, f.into(), l, c);
         (Some(file_name.into_owned()), Some(line_num), Some(col_num))
       }
       (f, l, c) => (f, l, c),
@@ -370,7 +372,7 @@ impl JsStackFrame {
         return Some(o);
       };
       let (file, line, col) =
-        apply_source_map(&mut source_mapper, file.into(), line, col);
+        apply_source_map(scope, &mut source_mapper, file.into(), line, col);
       Some(format!("{before}{file}:{line}:{col}{after}"))
     });
 
@@ -408,7 +410,7 @@ impl JsStackFrame {
     let state = JsRuntime::state_from(scope);
     let mut source_mapper = state.source_mapper.borrow_mut();
     let (file_name, line_num, col_num) =
-      apply_source_map(&mut source_mapper, f.into(), l, c);
+      apply_source_map(scope, &mut source_mapper, f.into(), l, c);
     Some(JsStackFrame::from_location(
       Some(file_name.into_owned()),
       Some(line_num),
@@ -515,7 +517,7 @@ impl JsError {
     Self::inner_from_v8_exception(scope, exception, Default::default())
   }
 
-  pub fn from_v8_message<'a>(
+  pub(crate) fn from_v8_message<'a>(
     scope: &'a mut v8::HandleScope,
     msg: v8::Local<'a, v8::Message>,
   ) -> Self {
@@ -525,41 +527,36 @@ impl JsError {
 
     let exception_message = msg.get(scope).to_rust_string_lossy(scope);
 
-    // Convert them into Vec<JsStackFrame>
-    let mut frames: Vec<JsStackFrame> = vec![];
-    let mut source_line = None;
-    let mut source_line_frame_index = None;
-
-    if let Some(stack_frame) = JsStackFrame::from_v8_message(scope, msg) {
-      frames = vec![stack_frame];
-    }
-    {
-      let state = JsRuntime::state_from(scope);
-      let mut source_mapper = state.source_mapper.borrow_mut();
-      for (i, frame) in frames.iter().enumerate() {
-        if let (Some(file_name), Some(line_number)) =
-          (&frame.file_name, frame.line_number)
-        {
-          if !file_name.trim_start_matches('[').starts_with("ext:") {
-            source_line = source_mapper.get_source_line(file_name, line_number);
-            source_line_frame_index = Some(i);
-            break;
-          }
-        }
-      }
-    }
-
-    Self {
+    let mut js_error = Self {
       name: None,
       message: None,
       exception_message,
       cause: None,
-      source_line,
-      source_line_frame_index,
-      frames,
+      source_line: None,
+      source_line_frame_index: None,
+      frames: vec![],
       stack: None,
       aggregated: None,
+    };
+
+    let Some(stack_frame) = JsStackFrame::from_v8_message(scope, msg) else {
+      return js_error;
+    };
+
+    let state = JsRuntime::state_from(scope);
+    let mut source_mapper = state.source_mapper.borrow_mut();
+    if let (Some(file_name), Some(line_number)) =
+      (&stack_frame.file_name, stack_frame.line_number)
+    {
+      if !file_name.trim_start_matches('[').starts_with("ext:") {
+        js_error.source_line =
+          source_mapper.get_source_line(file_name, line_number);
+        js_error.source_line_frame_index = Some(0);
+      }
     }
+
+    js_error.frames = vec![stack_frame];
+    js_error
   }
 
   fn inner_from_v8_exception<'a>(
@@ -678,14 +675,14 @@ impl JsError {
       {
         let state = JsRuntime::state_from(scope);
         let mut source_mapper = state.source_mapper.borrow_mut();
-        for (i, frame) in frames.iter().enumerate() {
+        for (index, frame) in frames.iter().enumerate() {
           if let (Some(file_name), Some(line_number)) =
             (&frame.file_name, frame.line_number)
           {
             if !file_name.trim_start_matches('[').starts_with("ext:") {
               source_line =
                 source_mapper.get_source_line(file_name, line_number);
-              source_line_frame_index = Some(i);
+              source_line_frame_index = Some(index);
               break;
             }
           }
@@ -749,13 +746,35 @@ impl std::error::Error for JsError {}
 
 impl Display for JsError {
   fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    // eprintln!("inside js error {}", self.source_line.is_some());
     if let Some(stack) = &self.stack {
+      // eprintln!("inside js error stack");
       let stack_lines = stack.lines();
       if stack_lines.count() > 1 {
         return write!(f, "{stack}");
       }
     }
+
     write!(f, "{}", self.exception_message)?;
+    if let Some(source_line) = self.source_line.as_ref() {
+      writeln!(f)?;
+      write!(f, "  {}", source_line)?;
+      let column_number = self
+        .source_line_frame_index
+        .and_then(|i| self.frames.get(i).unwrap().column_number);
+      if let Some(column_number) = column_number {
+        let mut s = String::new();
+        for _i in 0..(column_number - 1) {
+          if source_line.chars().nth(_i as usize).unwrap() == '\t' {
+            s.push('\t');
+          } else {
+            s.push(' ');
+          }
+        }
+        s.push('^');
+        write!(f, "  {}", s)?;
+      }
+    }
     let location = self.frames.first().and_then(|f| f.maybe_format_location());
     if let Some(location) = location {
       write!(f, "\n    at {location}")?;

core/examples/ts_module_loader.rs

@@ -124,8 +124,16 @@ impl ModuleLoader for TypescriptModuleLoader {
     ModuleLoadResponse::Sync(load(source_maps, module_specifier))
   }
 
-  fn get_source_map(&self, specifier: &str) -> Option<Vec<u8>> {
-    self.source_maps.borrow().get(specifier).cloned()
+  fn get_source_map_for_file(&self, file_name: &str) -> Option<Vec<u8>> {
+    self.source_maps.borrow().get(file_name).cloned()
+  }
+
+  fn load_source_map_file(
+    &self,
+    source_map_file_name: &str,
+    _file_name: &str,
+  ) -> Option<Vec<u8>> {
+    std::fs::read(source_map_file_name).ok()
   }
 }
 

core/modules/loaders.rs

@@ -98,11 +98,34 @@ pub trait ModuleLoader {
 
   /// Returns a source map for given `file_name`.
   ///
-  /// This function will soon be deprecated or renamed.
-  fn get_source_map(&self, _file_name: &str) -> Option<Vec<u8>> {
+  /// Some embedders might opt into stripping out inlined source map from the source
+  /// code before it's loaded into V8. The source mapping logic will first ask
+  /// embedder to provide a source map for given file, before falling back
+  /// to looking for source map inlined in the code.
+  fn get_source_map_for_file(&self, _file_name: &str) -> Option<Vec<u8>> {
     None
   }
 
+  /// Returns a source map file.
+  ///
+  /// This is fallback API for [`Self::get_source_map_for_file`] that will only be called
+  /// if a module contains magic comment like `//# sourceMappingURL=foo.js.map`.
+  ///
+  /// Embedders might apply additional logic to decide if the source map should be returned.
+  /// Eg. if a local file tries to link to a remote source map, embedder might opt into
+  /// refusing to load it.
+  fn load_source_map_file(
+    &self,
+    _source_map_file_name: &str,
+    _file_name: &str,
+  ) -> Option<Vec<u8>> {
+    None
+  }
+
+  /// Return an "original" version of the given line for a file.
+  ///
+  /// In the future this API might be deprecated in favor of handling it internally
+  /// in `deno_core` using contents of the source map.
   fn get_source_mapped_source_line(
     &self,
     _file_name: &str,

core/ops_builtin_v8.rs

@@ -1082,7 +1082,7 @@ pub fn op_current_user_call_site(
     let application = js_runtime_state
       .source_mapper
       .borrow_mut()
-      .apply_source_map(&file_name, line_number, column_number);
+      .apply_source_map(scope, &file_name, line_number, column_number);
 
     match application {
       SourceMapApplication::Unchanged => {