where to delete database and close connection after all tests using mocha - unit-testing

Question

I'm trying to figure out where to put a function to delete database and close connection after all tests have run.
Here are my nested tests:
//db.connection.db.dropDatabase();
//db.connection.close();
describe('User', function(){
beforeEach(function(done){
});
after(function(done){
});
describe('#save()', function(){
beforeEach(function(done){
});
it('should have username property', function(done){
user.save(function(err, user){
done();
});
});
// now try a negative test
it('should not save if username is not present', function(done){
user.save(function(err, user){
done();
});
});
});
describe('#find()', function(){
beforeEach(function(done){
user.save(function(err, user){
done();
});
});
it('should find user by email', function(done){
User.findOne({email: fakeUser.email}, function(err, user){
done();
});
});
it('should find user by username', function(done){
User.findOne({username: fakeUser.username}, function(err, user){
done();
});
});
});
});
Nothing seems to work. I get Error: timeout of 2000ms exceeded

Answer 1

You can define a "root" after() hook before the 1st describe() to handle cleanup:
after(function (done) {
db.connection.db.dropDatabase(function () {
db.connection.close(function () {
done();
});
});
});
describe('User', ...);
Though, the error you're getting may be from the 3 asynchronous hooks that aren't informing Mocha to continue. These need to either call done() or skip the argument so they can be treated as synchronous:
describe('User', function(){
beforeEach(function(done){ // arg = asynchronous
done();
});
after(function(done){
done()
});
describe('#save()', function(){
beforeEach(function(){ // no arg = synchronous
});
// ...
});
});
From the docs:
By adding a callback (usually named done) to it() Mocha will know that it should wait for completion.

Answer 2

I implemented it a bit different.
I removed all documents in the "before" hook - found it a lot faster than dropDatabase().
I used Promise.all() to make sure all documents were removed before exiting the hook.
beforeEach(function (done) {
function clearDB() {
var promises = [
Model1.remove().exec(),
Model2.remove().exec(),
Model3.remove().exec()
];
Promise.all(promises)
.then(function () {
done();
})
}
if (mongoose.connection.readyState === 0) {
mongoose.connect(config.dbUrl, function (err) {
if (err) {
throw err;
}
return clearDB();
});
} else {
return clearDB();
}
});