fix(cli/fmt_errors): don't panic on source line formatting errors

Author: nayeemrmn

cli/fmt_errors.rs

@@ -177,12 +177,23 @@ fn format_maybe_source_line(
   if source_line.is_empty() || source_line.len() > SOURCE_ABBREV_THRESHOLD {
     return "".to_string();
   }
+  if source_line.contains("Couldn't format source line: ") {
+    return format!("\n{}", source_line);
+  }
 
   assert!(start_column.is_some());
   assert!(end_column.is_some());
   let mut s = String::new();
   let start_column = start_column.unwrap();
   let end_column = end_column.unwrap();
+
+  if start_column as usize >= source_line.len() {
+    return format!(
+      "\n{} Couldn't format source line: Column {} is out of bounds (source may have changed at runtime)",
+      crate::colors::yellow("Warning"), start_column + 1,
+    );
+  }
+
   // TypeScript uses `~` always, but V8 would utilise `^` always, even when
   // doing ranges, so here, if we only have one marker (very common with V8
   // errors) we will use `^` instead.

cli/proc_state.rs

@@ -622,8 +622,14 @@ impl SourceMapGetter for ProcState {
         // Do NOT use .lines(): it skips the terminating empty line.
         // (due to internally using .split_terminator() instead of .split())
         let lines: Vec<&str> = out.source.split('\n').collect();
-        assert!(lines.len() > line_number);
-        lines[line_number].to_string()
+        if line_number >= lines.len() {
+          format!(
+            "{} Couldn't format source line: Line {} is out of bounds (source may have changed at runtime)",
+            crate::colors::yellow("Warning"), line_number + 1,
+          )
+        } else {
+          lines[line_number].to_string()
+        }
       })
     } else {
       None