我可以从Mocha单元测试中删除文件吗？

Question

Trying a few node.js filesystem checks (to confirm if environment is functioning correctly) When I write my fs.unlink or fs.unlinkSync outside of Mocha it deletes the file as expected:

var fs = require('fs');

var newFile = new Date().getTime() +".txt";

fs.writeFile(newFile, "hello!", function (err) {
    if (err) console.log(err);
    // console.log("Created file: "+newFile);
    fs.readdir(__dirname, function(err, list) {
        // console.log(list)
        console.log(list.indexOf(newFile) > -1)
        fs.unlinkSync(newFile);
        console.log('successfully deleted '+newFile);
        // console.log("Deleted: "+newFile)
        fs.readdir(__dirname, function(err, list) {
            if (err) throw err;
            console.log(list.indexOf(newFile) === -1);
        });
    });
});

But when I try the exact same code from inside a mocha test it does not delete the file...

var chai   = require('chai');
var assert = chai.assert; 
var fs     = require('fs');

describe('Node.js Environment Checks', function(){
  describe('Basic IO', function(){
    it('CREATE (temporary) file tests create/write access to FS', function(){
        // setup
        var newFile = new Date().getTime() +".txt";

        fs.writeFile(newFile, "hello!", function (err) {
            if (err) console.log(err);
            // console.log("Created file: "+newFile);
            fs.readdir(__dirname, function(err, list) {
                // console.log(list)
                assert.isTrue(list.indexOf(newFile) > -1)
                fs.unlinkSync(newFile);
                console.log('successfully deleted '+newFile);
                // console.log("Deleted: "+newFile)
                fs.readdir(__dirname, function(err, list) {
                    if (err) throw err;
                    assert.isTrue(list.indexOf(newFile) === -1);
                });
            });
        });
    })
  })
}) // end node env checks

Am I missing something...?

note: I created an issue on GitHub: https://github.com/visionmedia/mocha/issues/1058
(If I get a reply there first I will mirror it here)

Answer 1

Use the asynchronous form of testing. Change your it call so that the callback gets the done parameter:

it('CREATE (temporary) file tests create/write access to FS', function(done){

And call it in your innermost async callback:

            fs.readdir(__dirname, function(err, list) {
                if (err) throw err;
                assert.isTrue(list.indexOf(newFile) === -1);
                done();
            });