url-path-to-local-path

Safely convert req.path into a local path.

Goals

• Consistent behavior with /foo and /foo/
• Consistent behavior with /foo finding /foo.html
• Check for existence of the file
• Set a different extension for local file, req.path might be index.html while local file is index.md
• Option to test for a series of local extensions ['.md', '.html']
• Protect from path traversal

Usage

var UrlPathToLocalPath = require('@ryanburnette/url-path-to-local-path');

var getLocalPath = UrlPathToLocalPath({
  context: './content/', // where is the content?
  localExtension: '.ejs' // or use localExtensions with an Array to try multiple extensions
});

// Express middleware example
module.exports = function (req, res, next) {
  getLocalPath(req.path)
    .then(function (localPath) {
      return fs.promises.readFile(localPath, 'utf8');
    })
    .then(function (html) {
      res.send(html);
    })
    // throws an error if no local path found, we'll catch that
    .catch(function (error) {
      next();
    });
};

Options

• context Working directory for content.
• localExtension If the local files have a different extension such as .md or .ejs
• localExtensions Use this with an array if multiple extensions should be tested