Add AffectedScope-decorator

[fraxachun]

Description

Use this decorator in following cases:

• You don't have an entity to check with @AffectedEntity
• You want to check for a combination of content scope values.

Example:

@Query(() => [Product])
@AffectedScope((args) => ({ country: args.country, department: args.department }))
async products(@Args("country", { type: () => string }) id: string, @Args("department", { type: () => string }): Promise<Product[]> {
    // Note: you can trust "country" and "department" being in a valid scope in the sense that the user must have a content scope which is a combination of these dimensions:
    // [{ country: "AT", department: "main" }]; // ok
    // [{ country: "AT" }, { department: "main" }]; // not sufficient
}

Further Information

• Task: https://vivid-planet.atlassian.net/browse/COM-2459

[fraxachun]

See 352cca4

Why this change?

• It's more correct than Treat null and undefined scope dimensions the same in AccessControlService#isAllowed #2643
• It makes handling optional values easier

[johnnyomair]

Isn't changing this a breaking change? Now null isn't treated as "not existing" any longer, but rather "no specific value set". I can imagine that this would break access control in some of our applications.

[fraxachun]

The main difference is that it's a bit more loose.

Before:
{foo: undefined} forced the user having {foo: null} or {foo: undefined}
{foo: null} forced the user having {foo: null} or {foo: undefined}

Now:
{foo: undefined} doesn't require to have a content scope
{foo: null} forces the user having {foo: null}

It's breaking indeed if the user's content-scope consists of undefined values:
Breaking:
{foo: null} isn't allowed anymore if the user has {foo: undefined}
Can we neglect this? If not, re-adding these lines should be make it compatible again.

[fraxachun]

We also could revert this breaking change. It's not really necessary, but it makes handling optional values easier in argsToScope easier.

[johnnyomair]

Can we neglect this? If not, re-adding these lines should be make it compatible again.

@Ben-Ho @kaufmo what do you think about this? To my best knowledge you're the only ones that have projects with optional scope dimensions.