LoadStrategy not honored on ManyToOne

[evantrimboli]

Describe the bug
If I specify the strategy on a ManyToOne to be joined, the query doesn't do a join to load.

Stack trace
N/A

To Reproduce
Steps to reproduce the behavior:

Consider the following entities:

@Entity()
export default class Order {
  @PrimaryKey()
  id!: number;

  @OneToMany(() => OrderItem, ({ order }) => order)
  orderItems = new Collection<OrderItem>(this);
}

@Entity()
export default class OrderItem {
  @PrimaryKey()
  id!: number;

  @ManyToOne({
    entity: () => Order,
    strategy: LoadStrategy.JOINED,
    eager: true
  })
  order!: Order;
}

Finally, run a query to pull order items:

orm.em.getRepository<OrderItem>('OrderItem').find({
  id: {
    $gt: 100
  }
})

The generated query is:

select "e0".* from "order_item" as "e0" where "e0"."id" > 100

Expected behavior
There should be a join in the query to populate the Order entity.

Additional context
Specifying populate directly in the query does produce the join:

orm.em
  .getRepository<OrderItem>('OrderItem')
  .find({ id: { $gt: 100 } }, { populate: { order: LoadStrategy.JOINED } });

select "e0"."id", "e0"."order_id", "o1"."id" as "o1__id" from "order_item" as "e0" left join "order" as "o1" on "e0"."order_id" = "o1"."id" where "e0"."id" > 100

Versions

Dependency	Version
node	14.15.4
typescript	4.1.5
mikro-orm	4.5.0
your-driver	postgresql - 4.5.0

[B4nan]

I think this is more about combining strategy with eager: true (eager loading is implemented as automatically filling the populate for you).

[evantrimboli]

Just FYI, I tried it with only eager: true and omitted the load strategy and I had the same result, no join.

@ManyToOne({
  entity: () => Order,
  eager: true
})