huncwot/middleware/serve.js

A Programming Environment for TypeScript apps built on top of VS Code

// Copyright 2019 Zaiste & contributors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

const debug = require('debug')('huncwot:static');

const fs = require('fs-extra');

const path = require('path');
const assert = require('assert');
const mime = require('mime-types');
const { parse } = require('url');

const serve = (root, opts = { index: 'index.html' }) => {
  assert(root, 'you need to specify `root` directory');
  debug('"%s" %j', root, opts);

  return async (context, next) => {
    const method = context.request.method;
    const { pathname } = parse(context.request.url, true); // TODO Test perf vs RegEx
    debug('"%s" -> %s', method, pathname);

    if (method.toUpperCase() === 'HEAD' || method.toUpperCase() === 'GET') {
      try {
        let file = path.join(root, pathname);
        let stats = await fs.stat(file);

        if (stats.isDirectory()) {
          file = path.join(file, opts.index);
          stats = await fs.stat(file);
        }

        let type = path.extname(file);

        return {
          statusCode: 200,
          headers: {
            'Content-Type': mime.lookup(type) || 'application/octet-stream'
          },
          body: fs.createReadStream(file),
          additional: {
            size: stats.size
          }
        };
      } catch (error) {
        return next(context);
      }
    } else {
      return next(context);
    }
  };
};

module.exports = serve;