ng-generate: fails if @schematics/angular is not installed

Bug, enhancement request, or proposal:

Received error An unhandled exception occurred: Cannot find module '@schematics/angular/utility/ast-utils' while performing A9 upgrade, "@angular-devkit/schematics": "^9.0.2", "@angular/cli": "9.0.2",

[devversion]

We no longer import AST utils from @schematics/angular, so this should no longer be an issue for ng update. Though, our generate schematics still rely on @schematics/angular. We could:

1. Spend time figuring out where we can have shared schematic logic.
2. Add @schematics/angular as explicit dependency to the CDK.
3. Always assume that @schematics/angular is installed, and print a good error if it’s not installed for some reason.

@jelbourn I’d prefer (1) since we need it for @angular/core too. For components, going with (2) would be fine too. One concern might be that the package is unnecessarily downloaded in some situations. Though it’s definitely correct to have it as dependency if we directly access it. If we go with (1), we’d most likely still need an dependency on @schematics/angular too.

I created a ticket for working this out long-term: COMP-295. We can defer this until the overall decision is made (and applies for framework too). The ng update issue has been solved, and it’s only a rare issue for ng generate now.

[devversion]

This is blocked on us figuring out how schematic utilities should be shared across Angular packages.