This package can be used to configure AutoFixture so that it can create instances of classes inheriting from PageModel.
You can use this extension by simply invoking the AddRazorPages method on the IFixture instance at hand.
var fixture = new Fixture().AddRazorPages();
var page = fixture.Create<IndexPage>();
var result = await page.OnGetAsync(cancellationToken: default);
Assert.That(result, Is.InstanceOf<PageResult>());