terminal-cv/node_modules/@parcel/fs-write-stream-atomic/test/basic.js

var fs = require('graceful-fs');
var test = require('tap').test;
var path = require('path');
var writeStream = require('../index.js');

var rename = fs.rename;
fs.rename = function(from, to, cb) {
  setTimeout(function() {
    rename(from, to, cb);
  }, 100);
};

test('basic', function(t) {
  // open 10 write streams to the same file.
  // then write to each of them, and to the target
  // and verify at the end that each of them does their thing
  var target = path.resolve(__dirname, 'test.txt');
  var n = 10;

  // We run all of our assertions twice:
  //   once for finish, once for close
  // There are 6 assertions, two fixed, plus 4 lines in the file.
  t.plan(n * 2 * 6);

  var streams = [];
  for (var i = 0; i < n; i++) {
    var s = writeStream(target);
    s.on('finish', verifier('finish', i));
    s.on('close', verifier('close', i));
    streams.push(s);
  }

  function verifier(ev, num) {
    return function() {
      if (ev === 'close') {
        t.equal(this.__emittedFinish, true, num + '. closed only after finish');
      } else {
        this.__emittedFinish = true;
        t.equal(ev, 'finish', num + '. finished');
      }

      // make sure that one of the atomic streams won.
      var res = fs.readFileSync(target, 'utf8');
      var lines = res.trim().split(/\n/);
      lines.forEach(function(line, lineno) {
        var first = lines[0].match(/\d+$/)[0];
        var cur = line.match(/\d+$/)[0];
        t.equal(cur, first, num + '. line ' + lineno + ' matches');
      });

      var resExpr = /^first write \d+\nsecond write \d+\nthird write \d+\nfinal write \d+\n$/;
      t.similar(res, resExpr, num + '. content matches');
    };
  }

  // now write something to each stream.
  streams.forEach(function(stream, i) {
    stream.write('first write ' + i + '\n');
  });

  // wait a sec for those writes to go out.
  setTimeout(function() {
    // write something else to the target.
    fs.writeFileSync(target, 'brutality!\n');

    // write some more stuff.
    streams.forEach(function(stream, i) {
      stream.write('second write ' + i + '\n');
    });

    setTimeout(function() {
      // Oops!  Deleted the file!
      fs.unlinkSync(target);

      // write some more stuff.
      streams.forEach(function(stream, i) {
        stream.write('third write ' + i + '\n');
      });

      setTimeout(function() {
        fs.writeFileSync(target, 'brutality TWO!\n');
        streams.forEach(function(stream, i) {
          stream.end('final write ' + i + '\n');
        });
      }, 50);
    }, 50);
  }, 50);
});

test('cleanup', function(t) {
  fs.readdirSync(__dirname)
    .filter(function(f) {
      return f.match(/^test.txt/);
    })
    .forEach(function(file) {
      fs.unlinkSync(path.resolve(__dirname, file));
    });
  t.end();
});