feat: raises if name is invalid

Signed-off-by: Eduardo Borsa <borsa.dado@gmail.com>

Author: edborsa

lib/mix/tasks/install.ex

@@ -338,6 +338,7 @@ defmodule Mix.Tasks.Beacon.Install do
 
     cond do
       !Beacon.Types.Site.valid?(site) -> raise_with_help!("Invalid site name. It should not contain special characters.")
+      !Beacon.Types.Site.valid_name?(site) -> raise_with_help!("Invalid site name. The site name can't start with \"beacon_\".")
       :default -> options
     end
   end

test/mix/tasks/install_test.exs

@@ -443,6 +443,11 @@ defmodule Mix.Tasks.Beacon.InstallTest do
         Install.run(["--site", "my@site!"])
       end
 
+      # Invalid site name
+      assert_raise Mix.Error, fn ->
+        Install.run(["--site", "beacon_"])
+      end
+
       # Invalid option
       assert_raise OptionParser.ParseError, ~r/1 error found!\n--invalid-argument : Unknown option/, fn ->
         Install.run(["--invalid-argument", "invalid"])