I would like to be able to easily check if the token has expired before making any http requests.
https://angular.io/guide/http#intercepting-all-requests-or-responses
When did Angular release that functionality? (version)
Does a current Ionic install use that Angular version when creating a new project?
If yes: It works.
If not: It does not work.
Angular version 4.3.0-rc.0 beta
Its not in the stable release yet
You can check which version of Angular you’re running in package.json or package-lock.json. You can update to a newer version of Angular at your own risk if you want access to newer Angular features, but Ionic is always a bit behind for code stability.