angular-docs-cn/packages/core/schematics/migrations/activated-route-snapshot-fragment/README.md

ActivatedRouteSnapshot.fragment migration

The value if ActivatedRouteSnapshot.fragment is becoming nullable. This migration adds non-null assertions to it.

Before

import { Component } from '@angular/core';
import { ActivatedRouteSnapshot } from '@angular/router';

@Component({})
export class YourComponent {
  private _activatedRouteSnapshot: ActivatedRouteSnapshot;

  getFragmentValue() {
    return this._activatedRouteSnapshot.fragment.value;
  }
}

After

import { Component } from '@angular/core';
import { ActivatedRoute } from '@angular/router';

@Component({})
export class YourComponent {
  private _activatedRouteSnapshot: ActivatedRouteSnapshot;

  getFragmentValue() {
    return this._activatedRouteSnapshot.fragment!.value;
  }
}