Activation guard of child component affects creation/rendering of the parent component #18975

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[x] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

Preconditions: there is a nested routing tree (like /comp_a/comp_b/comp_c) with activation guards for each component. Activation guards of all components return "true" after some async operation/timeout.

UseCase 1.1
open comp_a => waiting for CompA guard => render CompA
open comp_b => waiting for CompB guard => render CompB
open comp_c => waiting for CompC guard => render CompC

UseCase 1.2
open /comp_a/comp_b/comp_c => waiting for CompA guard => waiting for CompB guard => waiting for CompC guard => render CompA + render CompB + render CompC

Preconditions: there is a nested routing tree (like /comp_a/comp_b/comp_c) with activation guards for each component. Activation guards of all components except the last one return "true" after some async operation/timeout. Guard of the last component returns "false" after some async operation/timeout.

UseCase 2.1
open comp_a => waiting for CompA guard => render CompA
open comp_b => waiting for CompB guard => render CompB
open comp_c => waiting for CompC guard => don't render CompC

UseCase 2.2
open /comp_a/comp_b/comp_c => waiting for CompA guard => waiting for CompB guard => waiting for CompC guard => don't render components at all

Expected behavior

"UseCase 1.1" and "UseCase 2.1" are ok

For "UseCase 1.2" expected:
open /comp_a/comp_b/comp_c => waiting for CompA guard => render CompA => waiting for CompB guard => render CompB => waiting for CompC guard => render CompC

For "UseCase 2.2" expceted:
open /comp_a/comp_b/comp_c => waiting for CompA guard => render CompA => waiting for CompB guard => render CompB => waiting for CompC guard => don't render CompC

Minimal reproduction of the problem with instructions

https://plnkr.co/edit/xpkHSCSEzTK9yoAPJbvG?p=preview
STR:

• click "show components"
• there will be log where guards are resolved one-by-one
• all components are appeared only after all guards are resolved

The issue is related to the b9e32c8
I totally agree that child CanActivate guard should wait for parent to comple, but parent components creation/rendering should not be affected by by child CanActivate guard (activation of the parent route snapshout should not wait until all child CanActivate guards are resolved successfully)

Environment

Angular version: 4.3.3