Fix BaseEntity finder methods to allow lazy relation conditions

[bogdan]

The following code:

const category = await Category.findOne();
const post = Post.findOne({category})

Results in typecheck error when Post#category is a lazy relation while the finder does work.

[bogdan]

@pleerock any feedback here?

[pleerock]

TBH I would like to avoid merging this change, because I want to change lazy relation concept in the future versions.

[bogdan]

@pleerock is there any described plan on that? Will there be breaking changes? What is expected date when this issue can be fixed with "lazy relation concent in the future versions"?

It is causing problems on our end because developers are very confused with this bug.

[pleerock]

There is no roadmap, but I was previously mentioned about it in other issues. Okay, let's merge it if its problematic with current version.

[bogdan]

@imnotjames fixed the issue. Can you please review again?

[bogdan]

@pleerock @imnotjames can you please merge this one?

[alumni]

@bogdan This PR broke find/findOne when used from EntityManager.

const p = entityManager.findOne(Post, { where: { id: 1 }});

Under TS 4.4.4, the inferred type of p is { id: number } instead of Post

[bogdan]

@alumni I can not reproduce that on current master. For me the type of p is Post | undefined.

[alumni]

@bogdan I check a bit more and it seems it's not particularly because of this PR, it only happens more often now, probably because of the added T | ... in line 11. We were already explicitly specifying the generic type in many cases (post = entityManager.find<Post>(Post, ...)) to avoid this problem. Probably if I find a simpler example than what I have now, I would also have a solution to it.

[brandon-leapyear]

✨ This is an old work account. Please reference @brandonchinn178 for all future communication ✨

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Note: the T | ... addition causes a regression: #8600