fix: pass ManyToMany onUpdate option to foreign key metadata

[fan-tom]

Closes: #4980

I'm not sure if onDelete/onUpdate options are handled properly, it seems to me that they must be applied to foreign keys pointing to OPPOSITE entity, not to entity they are used in, but such changes break existing tests, so I considered to fix this issue not breaking them.

[pleerock]

Based on your comments what I understood is that we need to set onUpdate and onDelete for every column in the junction table separately, am I right? If so, this temporary change doesn't make sense and we probably need to remove this option and introduce it for @JoinTable's joinColumn option?:

@ManyToMany(
        () => Book,
        book => book.authors
    )
    @JoinTable({
        name: "author_to_books",
        joinColumn: {
            name: "author_id",
            referencedColumnName: "id",
            onDelete: "CASCADE",
            onUpdate: "CASCADE"
        },
        inverseJoinColumn: {
            name: "book_id",
            referencedColumnName: "id",
            onDelete: "CASCADE",
            onUpdate: "CASCADE"
        },
    })

Also, before any change will be merged we need to be sure nothing will be broken for exist users and ORM wont generate any new queries for those who update the version. I'm a bit scary to merge such kind of things.

[fan-tom]

I just want to say that when I write

class Author {
  @ManyToMany(type => Book, {
    onUpdate: 'CASCADE',
    onDelete: 'CASCADE',
  })
  books: Book[];
}

class Book {
  @JoinTable()
  @ManyToMany(type => Author, {
    onUpdate: 'NO ACTION',
    onDelete: 'NO ACTION',
  })
  authors: Author[];
}

I expect that I can update id's of books and get fk updated accordingly, but cannot update author's id's, like when you use ManyToOne and OneToOne, you apply those decorators inside referencing table and onDelete/onUpdate options are applied to links to REFERENCED table. But in case of ManyToMany when I set onDelete: 'CASCADE' inside Author entity, I get it applied to link to CURRENT table(Author), instead of link to REFERENCED table(Book).

What about affecting current users, I just added missing property handling code for onUpdate option, that works the same way onDelete works currently, just like people requested in issue, and fixed the bug that single onDelete option was used for both sides, so I don't understand what things you are scary about.

[fan-tom]

Is it related issue? #3505

[imnotjames]

This makes sense. Can you rebase and get the new test suite kicking off?

[FabianScheidt]

I am facing both of the issues that are mentioned here. Wouldn't it make sense to merge @fan-tom's suggestion now and later come up with a change that involves the @JoinTable decorator as suggested by @pleerock?

[Ami777]

Why isn't this merged... 1 year later :|?

[jcrben]

@fan-tom up for rebasing for a merge as suggested by @imnotjames?

[fan-tom]

rebased

[AlexMesser]

thank you for contribution!