Respect to_form :as option in form field access (#2480)

lib/phoenix_component.ex

@@ -2094,15 +2094,13 @@ defmodule Phoenix.Component do
  attr.(:for, :any, required: true, doc: "An existing form or the form source data.")
 
  attr.(:action, :string,
- default: nil,
  doc: """
  The action to submit the form on.
  This attribute must be given if you intend to submit the form to a URL without LiveView.
  """
  )
 
  attr.(:as, :atom,
- default: nil,
  doc: """
  The server side parameter in which all params for this form
  will be collected. For example, setting `as: :user_params` means

test/phoenix_component/components_test.exs

@@ -292,6 +292,25 @@ defmodule Phoenix.LiveView.ComponentsTest do
  ] = html
  end
 
+ test "generates form with prebuilt form and :as" do
+ assigns = %{form: to_form(%{}, as: :data)}
+
+ template = ~H"""
+ <.form :let={f} for={@form}>
+ <input id={f[:foo].id} name={f[:foo].name} type="text" />
+ </.form>
+ """
+
+ html = parse(template)
+
+ assert [
+ {"form", [],
+ [
+ {"input", [{"id", "data_foo"}, {"name", "data[foo]"}, {"type", "text"}], []}
+ ]}
+ ] = html
+ end
+
  test "generates form with prebuilt form and options" do
  assigns = %{form: to_form(%{})}