node/test/parallel/test-http-get-pipeline-problem.js

'use strict';
// In previous versions of Node.js (e.g., 0.6.0), this sort of thing would halt
// after http.globalAgent.maxSockets number of files.
// See https://groups.google.com/forum/#!topic/nodejs-dev/V5fB69hFa9o
const common = require('../common');
const assert = require('assert');
const http = require('http');
const fs = require('fs');

http.globalAgent.maxSockets = 1;

common.refreshTmpDir();

const image = fs.readFileSync(`${common.fixturesDir}/person.jpg`);

console.log(`image.length = ${image.length}`);

const total = 10;
let requests = 0, responses = 0;

const server = http.Server(function(req, res) {
  if (++requests === total) {
    server.close();
  }

  setTimeout(function() {
    res.writeHead(200, {
      'content-type': 'image/jpeg',
      'connection': 'close',
      'content-length': image.length
    });
    res.end(image);
  }, 1);
});


server.listen(0, function() {
  for (let i = 0; i < total; i++) {
    (function() {
      const x = i;

      const opts = {
        port: server.address().port,
        headers: { connection: 'close' }
      };

      http.get(opts, function(res) {
        console.error(`recv ${x}`);
        const s = fs.createWriteStream(`${common.tmpDir}/${x}.jpg`);
        res.pipe(s);

        s.on('finish', function() {
          console.error(`done ${x}`);
          if (++responses === total) {
            checkFiles();
          }
        });
      }).on('error', function(e) {
        console.error('error! ', e.message);
        throw e;
      });
    })();
  }
});


let checkedFiles = false;
function checkFiles() {
  // Should see 1.jpg, 2.jpg, ..., 100.jpg in tmpDir
  const files = fs.readdirSync(common.tmpDir);
  assert(total <= files.length);

  for (let i = 0; i < total; i++) {
    const fn = `${i}.jpg`;
    assert.ok(files.includes(fn), `couldn't find '${fn}'`);
    const stat = fs.statSync(`${common.tmpDir}/${fn}`);
    assert.strictEqual(
      image.length, stat.size,
      `size doesn't match on '${fn}'. Got ${stat.size} bytes`);
  }

  checkedFiles = true;
}


process.on('exit', function() {
  assert.strictEqual(total, requests);
  assert.strictEqual(total, responses);
  assert.ok(checkedFiles);
});