code: function handleLogLine(file, line, opts, stylize) {
      currLine = line; // intentionally global
  
      // Emit non-JSON lines immediately.
      var rec;
      if (line && line.startsWith(String.fromCharCode(27) + "]0;"))
        line = line.replace(/^\033.+{/g, "{")
      if (!line) {
          if (!opts.strict) emit(line + '\n');
          return;
      } else if (line[0] !== '{') {
          if (!opts.strict) emit(line + '\n');  // not JSON
          return;
      } else {
          try {
              rec = JSON.parse(line);
          } catch (e) {
              if (!opts.strict) emit(line + '\n');
              return;
          }
      }
  
      if (!isValidRecord(rec)) {
          if (!opts.strict) emit(line + '\n');
          return;
      }
  
      if (!filterRecord(rec, opts))
          return;
  
      if (file === null)
          return emitRecord(rec, line, opts, stylize);
  
      return gotRecord(file, line, rec, opts, stylize);
  }
docs: Parses the given log line and either emits it right away (for invalid
  records) or enqueues it for emitting later when it's the next line to show.