add deleteMany method

[enniel]

No description provided.

[coveralls]

Coverage increased (+0.02%) to 96.725% when pulling c3a10cf on enniel:delete-many-method into baa5f64 on adonisjs:develop.

[thetutlage]

Couple of issues.

1. Your title says deleteMany though it has changes within find and findBy methods.
2. Also there is no point of having transactions for the fetch queries.

[enniel]

@thetutlage don't worked without transactions for the fetch queries

[enniel]

I tried to run deleteMany without transactions for find method, but got timeout error in tests:

  static deleteMany (ids, trx) {
     if (ids instanceof Array === false) {
       throw GE
         .InvalidArgumentException
         .invalidParameter(`${this.name}.deleteMany expects an array of ids`, ids)
     }
     return Promise.all(ids.map((id) => this.find(id))).then(instances => {
       return Promise.all(instances.map((instance) => instance.delete(trx)))
     })
   }

[thetutlage]

Coz you are finding inside that method. Also if you have an array of id, you should do a bulk delete, over deleting one row at a time.

user.query().whereIn('id', ids).delete()

There is no need for deleteMany