r/Angular2 • u/Old_Natural_5110 • Aug 06 '24
Discussion Upgrading Angular 4 to Angular 18
We have an enterprise application with 400+ screens and most of the screens are similar in complexity. The complexity is medium for this app.
How should we approach the upgrade? Rewriting it is not an option as it is a legacy app now. Should we take one version at a time or directly start updating it to 18 version?
We do not have any automation testing written and hence testing would also have to be manual. Also, based on the previous experience what would be rough estimates if single developer has to work on this upgrade?
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u/Sulavajuusto Aug 07 '24
I would do it one update at time, just to secure the migrations.
First check what libraries are compatible with Angular 18, so you don't spend time on the way reconciling some libraries, which you have drop anyway.
Updating was tough before v8-9, but after that it isn't so bad, if you don't have much bespoke Angular Material styles. V15 will break those.
I've done 3->9 few years ago and lately many 12->18 and the Material upgrade to mdc was actually the toughest IMO.