remove any existing DB file in transaction setup for sqlite

test/associations/has-many.test.js

@@ -1129,7 +1129,6 @@ describe(Support.getTestDialectTeaser("HasMany"), function() {
 
           this.User.hasMany(this.Task, { through: this.UserTask });
           this.Task.hasMany(this.User, { through: this.UserTask });
-
           this.sequelize = sequelize;
           return sequelize.sync({ force: true });
         }).then(function() {

test/sequelize.test.js

@@ -906,7 +906,7 @@ describe(Support.getTestDialectTeaser("Sequelize"), function () {
 
       it('supports nested transactions using savepoints', function(done) {
         var self = this
-        var User = this.sequelize.define('Users', { username: DataTypes.STRING })
+        var User = this.sequelizeWithTransaction.define('Users', { username: DataTypes.STRING })
 
         User.sync({ force: true }).success(function() {
           self.sequelizeWithTransaction.transaction().then(function(t1) {
@@ -994,7 +994,7 @@ describe(Support.getTestDialectTeaser("Sequelize"), function () {
 
       it('supports rolling back a nested transaction', function(done) {
         var self = this
-        var User = this.sequelize.define('Users', { username: DataTypes.STRING })
+        var User = this.sequelizeWithTransaction.define('Users', { username: DataTypes.STRING })
 
         User.sync({ force: true }).success(function() {
           self.sequelizeWithTransaction.transaction().then(function(t1) {
@@ -1019,7 +1019,7 @@ describe(Support.getTestDialectTeaser("Sequelize"), function () {
 
       it('supports rolling back outermost transaction', function(done) {
         var self = this
-        var User = this.sequelize.define('Users', { username: DataTypes.STRING })
+        var User = this.sequelizeWithTransaction.define('Users', { username: DataTypes.STRING })
 
         User.sync({ force: true }).success(function() {
           self.sequelizeWithTransaction.transaction().then(function(t1) {

test/support.js

@@ -38,14 +38,25 @@ var Support = {
     var dialect = Support.getTestDialect();
 
     if (dialect === 'sqlite') {
-      var options    = Sequelize.Utils._.extend({}, sequelize.options, { storage: path.join(__dirname, 'tmp', 'db.sqlite') })
-        , _sequelize = new Sequelize(sequelize.config.database, null, null, options);
-
-      if (callback) {
-        _sequelize.sync({ force: true }).success(function() { callback(_sequelize); });
-      } else {
-        return _sequelize.sync({ force: true }).return(_sequelize);
-      }
+      var p = path.join(__dirname, 'tmp', 'db.sqlite');
+
+      return new Sequelize.Promise(function (resolve, reject) {
+        // We cannot promisify exists, since exists does not follow node callback convention - first argument is a boolean, not an error / null
+        if (fs.existsSync(p)) {
+          resolve(Sequelize.Promise.promisify(fs.unlink)(p));
+        } else {
+          resolve();
+        }
+      }).then(function () {
+        var options    = Sequelize.Utils._.extend({}, sequelize.options, { storage: p })
+          , _sequelize = new Sequelize(sequelize.config.database, null, null, options);
+
+        if (callback) {
+          _sequelize.sync({ force: true }).success(function() { callback(_sequelize); });
+        } else {
+          return _sequelize.sync({ force: true }).return(_sequelize);
+        }
+      });
     } else {
       if (callback) {
         callback(sequelize);