Function makeExpressHandler

src/PromiseRouter.js:137–198

(appId, promiseHandler)

// Express handlers should never throw; if a promise handler throws we
// just treat it like it resolved to an error.
function makeExpressHandler(appId, promiseHandler) {
  return function (req, res, next) {
    try {
      const url = maskSensitiveUrl(req);
      const body = Object.assign({}, req.body);
      const method = req.method;
      const headers = req.headers;
      log.logRequest({
        method,
        url,
        headers,
        body,
      });
      promiseHandler(req)
        .then(
          result => {
            if (!result.response && !result.location && !result.text) {
              log.error('the handler did not include a "response" or a "location" field');
              throw 'control should not get here';
            }

            log.logResponse({ method, url, result });

            var status = result.status || 200;
            res.status(status);

            if (result.headers) {
              Object.keys(result.headers).forEach(header => {
                res.set(header, result.headers[header]);
              });
            }

            if (result.text) {
              res.send(result.text);
              return;
            }

            if (result.location) {
              res.set('Location', result.location);
              // Override the default expressjs response
              // as it double encodes %encoded chars in URL
              if (!result.response) {
                res.send('Found. Redirecting to ' + result.location);
                return;
              }
            }
            res.json(result.response);
          },
          error => {
            next(error);
          }
        )
        .catch(e => {
          log.error(`Error generating response. ${inspect(e)}`, { error: e });
          next(e);
        });
    } catch (e) {
      log.error(`Error handling request: ${inspect(e)}`, { error: e });