Better typings for router package

🚀 feature request

Relevant Package

@angular/router

Description

I’d want propose better typing for routes. I’ve summarized it all below:

ExtraOptions:

Member	Current type	Proposed type	Reason
preloadingStrategy	any	Type<PreloadingStrategy>	A more concrete type than any.

ActivatedRoute/ActivatedRouteSnapshot:

Member	Current type	Proposed type	Reason
component	Type<any> | string | null	Type<unknown> | null	component cannot be a string.

Route:

Member	Current type	Proposed type	Reason
canActivate	any[]	readonly (string | Type<CanActivate>)[]	It should accept only string or (readonly, optionally) array of classes.
canActivateChild	any[]	readonly (string | Type<CanActivateChild>)[]	It should accept only string or (readonly, optionally) array of classes.
canDeactivate	any[]	readonly (string | Type<CanDeactivate>)[]	It should accept only string or (readonly, optionally) array of classes.
canLoad	any[]	readonly (string | Type<CanLoad>)[]	It should accept only string or (readonly, optionally) array of classes.

Router:

Member	Current type	Proposed type	Reason
createUrlTree	any[]	readonly (boolean | number | string | Record<‘outlets’, Record<string, readonly string[]>>)[] correct if I’m missing any accepted type here	it should accept only correct types. Also, it should accept readonly arrays.
navigate	any[]	readonly (boolean | number | string | Record<‘outlets’, Record<string, readonly string[]>>)[] correct if I’m missing any accepted type here	It should accept only correct types. Also, it should accept readonly arrays.

RouterLink/RouterLinkWithHref:

Member	Current type	Proposed type	Reason
routerLink	string | any[]	string | readonly (boolean | number | string | Record<‘outlets’, Record<string, readonly string[]>>)[] correct if I’m missing any accepted type here	It should accept only correct types. Also, it should accept readonly arrays.

RouterLinkActive:

Member	Current type	Proposed type	Reason
routerLinkActive	string | string[]	string | readonly string[]	It should accept readonly arrays.

RouterOutlet:

Member	Current type	Proposed type	Reason
activate	EventEmitter<any>	EventEmitter<ComponentRef<unknown>>	A more concrete type than any.
deactivate	EventEmitter<any>	EventEmitter< ComponentRef<unknown>>	A more concrete type than any.
component	Object	ComponentRef<unknown>	A more concrete type than Object.

provideRoutes: The return type should be ValueProvider instead of any.

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Questions:

• Why Data and Navigation are types instead of interfaces?
• What about creating a type to not duplicate the accepted type of routerLink and Router#functions?
• Could RouterOutlet accept an optional generic argument to avoid explicit any?
• About immutability, do you have any pretension to make non-mutable properties like queryParams, queryParamMap, params and paramMap readonly?

[Airblader]

As a quick thought: when doing this we should also consider strictNullChecks by adding undefined and null where possible / necessary. For compatibility that’ll be required I think.

[dev054]

More 1 vote 🙏