fix: make Router.reachable/2 less strict (#698)

Author: leandrocp

lib/beacon/router.ex

@@ -270,10 +270,24 @@ defmodule Beacon.Router do
   # match and invalidate the `beacon_site` mount.
   def reachable?(%Beacon.Config{} = config, opts \\ []) do
     %{site: site, endpoint: endpoint, router: router} = config
+
     host = Keyword.get_lazy(opts, :host, fn -> endpoint.host() end)
-    prefix = router.__beacon_scoped_prefix_for_site__(site)
+
+    prefix =
+      Keyword.get_lazy(opts, :prefix, fn ->
+        router.__beacon_scoped_prefix_for_site__(site)
+      end)
 
     case Phoenix.Router.route_info(router, "GET", prefix, host) do
+      # bypass and allow booting beacon sites even though there's a route conflict
+      # but only for root paths, for example:
+      #   live /
+      #   beacon_site /
+      # that's because even though they share the same prefix,
+      # beacon can still serve pages at /:page
+      %{route: "/"} ->
+        true
+
       %{phoenix_live_view: {Beacon.Web.PageLive, _, _, %{extra: %{session: %{"beacon_site" => ^site}}}}} ->
         true
 

test/beacon/router_test.exs

@@ -63,14 +63,28 @@ defmodule Beacon.RouterTest do
   end
 
   describe "reachable?" do
-    test "test" do
+    setup do
       site = :host_test
       config = Beacon.Config.fetch!(site)
-      valid_host = "host.com"
+      [config: config]
+    end
 
+    test "match existing host", %{config: config} do
+      valid_host = "host.com"
       assert Router.reachable?(config, host: valid_host)
-      refute Router.reachable?(%{config | site: :my_site}, host: valid_host)
-      refute Router.reachable?(config, host: "other.com")
+    end
+
+    test "existing nested conflicting route", %{config: config} do
+      valid_host = "host.com"
+      refute Router.reachable?(config, host: valid_host, prefix: "/nested/some_page")
+    end
+
+    test "with no specific host", %{config: config} do
+      assert Router.reachable?(config, host: nil)
+    end
+
+    test "do not match any existing host/path", %{config: config} do
+      refute Router.reachable?(config, host: nil, prefix: "/nested/invalid")
     end
   end
 end

test/support/live_views.ex

@@ -0,0 +1,4 @@
+defmodule Beacon.BeaconTest.LiveViews.FooBarLive do
+  use Phoenix.LiveView
+  def render(assigns), do: ~H""
+end

test/support/router.ex

@@ -16,8 +16,17 @@ defmodule Beacon.BeaconTest.Router do
     beacon_site "/media", site: :s3_site
   end
 
-  # test :host
+  scope "/" do
+    pipe_through :browser
+
+    live_session :default do
+      live "/", Beacon.BeaconTest.LiveViews.FooBarLive
+      live "/nested/:page", Beacon.BeaconTest.LiveViews.FooBarLive
+    end
+  end
+
   scope path: "/", host: "host.com" do
+    pipe_through :browser
     beacon_site "/", site: :host_test
   end