fix(cli/rt/error_stack): Improve message line formatting (#7860)

1 files changed, 13 insertions, 3 deletions

diff --git a/core/error.rs b/core/error.rs
index 1aa67e26c..30aa88773 100644
--- a/core/error.rs
+++ b/core/error.rs
@@ -174,14 +174,24 @@ impl JsError {
 
       // Get the message by formatting error.name and error.message.
       let name = get_property(scope, exception, "name")
+        .filter(|v| !v.is_undefined())
         .and_then(|m| m.to_string(scope))
         .map(|s| s.to_rust_string_lossy(scope))
-        .unwrap_or_else(|| "undefined".to_string());
+        .unwrap_or_else(|| "Error".to_string());
       let message_prop = get_property(scope, exception, "message")
+        .filter(|v| !v.is_undefined())
         .and_then(|m| m.to_string(scope))
         .map(|s| s.to_rust_string_lossy(scope))
-        .unwrap_or_else(|| "undefined".to_string());
-      let message = format!("Uncaught {}: {}", name, message_prop);
+        .unwrap_or_else(|| "".to_string());
+      let message = if name != "" && message_prop != "" {
+        format!("Uncaught {}: {}", name, message_prop)
+      } else if name != "" {
+        format!("Uncaught {}", name)
+      } else if message_prop != "" {
+        format!("Uncaught {}", message_prop)
+      } else {
+        "Uncaught".to_string()
+      };
 
       // Access error.stack to ensure that prepareStackTrace() has been called.
       // This should populate error.__callSiteEvals.