An error subclass with separate messages for server logs and HTTP responses.

It supports a suggested HTTP status code and convenience methods for sending a response via ExpressJS.

Currently only @numbereight/logger loggers are supported.

if (!apiKey) {
  return new ClientPresentableError({
    clientMessage: `No API key was provided. You can add your API key in the 'Authorization' header as a bearer token.`,
    clientHeaders: { 'WWW-Authenticate': `Bearer realm="My Realm", charset="UTF-8"` },
    statusCode: 401,
    serverMeta: {
      url: req.originalUrl,
      userAgent: req.get('User-Agent') || null,
    },
  });
}

const app = express();

app.use((
  error: Error,
  req: Request,
  res: Response,
  _next: NextFunction
) => {
  const logger = new Logger();
  const meta = {
    path: req.path,
  };

  if (error instanceof ClientPresentableError) {
    error.logAndSend(res, logger, meta);
    return;
  }

  ...
}
);

Create a ClientPresentableError.

• clientMessage the message to show the client, typically as an HTTP response.
• clientHeaders (optional) headers to set in the HTTP response.
• statusCode the suggested HTTP status code for the response.
• serverMessage (optional) the message to log to the server, if different from the client message.
• serverMeta (optional) additional metadata to log to the server.

Use the statusCode to infer a suitable log level for the message.

• If >= 500, the level is error
• If >= 400, the level is warn
• Otherwise, the level is the default

Logs the serverMessage to the given logger, or uses the default logger from @numbereight/logging if none is given.

A meta object can be provided to add additional information to the log message.

Formats the serverMessage and any given meta as a loggable object.

Accepts an ExpressJS Response object or an object that has a similar API and sends the clientMessage in the body of the response. The headers will be updated according to clientHeaders and the status code will be set by statusCode.

Performs a log operation followed by a send operation, as defined above. This is typically the most used method when handling a ClientPresentableError.