Issue 2429, core implementation and the protocol change

src/liveedit-debugger.js

Index: src/liveedit-debugger.js
diff --git a/src/liveedit-debugger.js b/src/liveedit-debugger.js
index cfcdb818c97e0287a9dd2d0ea37917f0912588ae..451b146bde798e4b4c81b62c39d0adcb1b158630 100644
--- a/src/liveedit-debugger.js
+++ b/src/liveedit-debugger.js
@@ -76,7 +76,17 @@ Debug.LiveEdit = new function() {
     try {
       new_compile_info = GatherCompileInfo(new_source, script);
     } catch (e) {
-      throw new Failure("Failed to compile new version of script: " + e);
+      var failure =
+          new Failure("Failed to compile new version of script: " + e);
+      if (e instanceof SyntaxError) {
+        var details = {
+          type: "liveedit_compile_error",
+          syntaxErrorMessage: e.message
+        };
+        CopyErrorPositionToDetails(e, details);
+        failure.details = details;
+      }
+      throw failure;
     }
     var root_new_node = BuildCodeInfoTree(new_compile_info);
 
@@ -978,6 +988,31 @@ Debug.LiveEdit = new function() {
     return "LiveEdit Failure: " + this.message;
   };
 
+  function CopyErrorPositionToDetails(e, details) {
+    function createPositionStruct(script, position) {
+      if (position == -1) return;
+      var location = script.locationFromPosition(position, true);
+      if (location == null) return;
+      return {
+        line: location.line + 1,
+        column: location.column + 1,
+        position: position
+      };
+    }
+
+    if (!("scriptObject" in e) || !("startPosition" in e)) {
+      return;
+    }
+
+    var script = e.scriptObject;
+
+    var position_struct = {
+      start: createPositionStruct(script, e.startPosition),
+      end: createPositionStruct(script, e.endPosition)
+    };
+    details.position = position_struct;
+  }
+
   // A testing entry.
   function GetPcFromSourcePos(func, source_pos) {
     return %GetFunctionCodePositionFromSource(func, source_pos);