Can't specify allowed hosts in ng serve #64104

Command

serve

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

Following the vite documentation, I should be able to give specific allowed hosts, as a string array. In the Angular documentation, it does not seem to be possible because the option value type is only boolean. Hoping the documentation would be lying, I tried to specify a string array. It does not work, I get this error:

➜  app git:(main) ng serve --allowed-hosts my.host1.com 
Error: Invalid values:
  Argument: project, Given: "my.host1.com", Choices: "app"

I should be able to specify a given array of hosts to ng serve, since it is indeed an option in the vite documentation.

Minimal Reproduction

To reproduce the issue, you can just create a new app using ng new and try the command ng serve --allowed-hosts my.host1.com. Here is the app I tried it on: https://github.com/Lysoun/angular-ng-serve-allowed-hosts

Exception or Error

Error: Invalid values:
  Argument: project, Given: "my.host1.com", Choices: "app"

Your Environment

Angular CLI: 20.3.3
Node: 22.16.0
Package Manager: npm 10.9.2
OS: darwin arm64
    

Angular: 20.3.2
... common, compiler, compiler-cli, core, forms
... platform-browser, router

Package                      Version
------------------------------------
@angular-devkit/architect    0.2003.3
@angular-devkit/core         20.3.3
@angular-devkit/schematics   20.3.3
@angular/build               20.3.3
@angular/cli                 20.3.3
@schematics/angular          20.3.3
rxjs                         7.8.2
typescript                   5.9.2
zone.js                      0.15.1

Anything else relevant?

No response