Fix non-code affecting Dialyzer warnings

lib/webengine_kiosk.ex

@@ -158,7 +158,7 @@ defmodule WebengineKiosk do
     cmd = Path.join(priv_dir, "kiosk")
 
     if !File.exists?(cmd) do
-      Logger.error("Kiosk port application is missing. It should be at #{cmd}.")
+      _ = Logger.error("Kiosk port application is missing. It should be at #{cmd}.")
       raise "Kiosk port missing"
     end
 
@@ -236,30 +236,33 @@ defmodule WebengineKiosk do
   end
 
   def handle_info({port, {:exit_status, 0}}, %{port: port} = state) do
-    Logger.info("webengine_kiosk: normal exit from port")
+    _ = Logger.info("webengine_kiosk: normal exit from port")
     {:stop, :normal, state}
   end
 
   def handle_info({port, {:exit_status, status}}, %{port: port} = state) do
-    Logger.error("webengine_kiosk: unexpected exit from port: #{status}")
+    _ = Logger.error("webengine_kiosk: unexpected exit from port: #{status}")
     {:stop, :unexpected_exit, state}
   end
 
   defp handle_browser_message({:browser_crashed, reason, _exit_status}, state) do
-    Logger.error("webengine_kiosk: browser crashed: #{inspect(reason)}. Going home and hoping...")
+    _ =
+      Logger.error(
+        "webengine_kiosk: browser crashed: #{inspect(reason)}. Going home and hoping..."
+      )
 
     # Try to recover by going back home
     send_port(state, Message.go_to_url(state.homepage))
     {:noreply, state}
   end
 
   defp handle_browser_message({:console_log, log}, state) do
-    Logger.warn("webengine_kiosk(stderr): #{log}")
+    _ = Logger.warn("webengine_kiosk(stderr): #{log}")
     {:noreply, state}
   end
 
   defp handle_browser_message(message, state) do
-    Logger.debug("webengine_kiosk: received #{inspect(message)}")
+    _ = Logger.debug("webengine_kiosk: received #{inspect(message)}")
     {:noreply, state}
   end
 

lib/webengine_kiosk/input_event.ex

@@ -58,7 +58,7 @@ if Code.ensure_loaded?(SystemRegistry) do
 
     defp chgrp(devname, gid) do
       path = Path.join(@dev, devname)
-      Logger.info("webengine_kiosk: chgrp #{path}")
+      _ = Logger.info("webengine_kiosk: chgrp #{path}")
       File.chgrp(path, gid)
     end
 

lib/webengine_kiosk/message.ex

@@ -18,29 +18,29 @@ defmodule WebengineKiosk.Message do
 
   @moduledoc false
 
-  @spec go_to_url(String.t()) :: binary()
+  @spec go_to_url(String.t()) :: <<_::8, _::_*8>>
   def go_to_url(url), do: <<@msg_go_to_url, url::binary>>
 
-  @spec run_javascript(String.t()) :: binary()
+  @spec run_javascript(String.t()) :: <<_::8, _::_*8>>
   def run_javascript(code), do: <<@msg_run_javascript, code::binary>>
 
-  @spec blank(boolean()) :: binary()
+  @spec blank(boolean()) :: <<_::16>>
   def blank(true), do: <<@msg_blank, 1>>
   def blank(false), do: <<@msg_blank, 0>>
 
-  @spec reload() :: binary()
+  @spec reload() :: <<_::8>>
   def reload(), do: <<@msg_reload>>
 
-  @spec go_back() :: binary()
+  @spec go_back() :: <<_::8>>
   def go_back(), do: <<@msg_go_back>>
 
-  @spec go_forward() :: binary()
+  @spec go_forward() :: <<_::8>>
   def go_forward(), do: <<@msg_go_forward>>
 
-  @spec stop_loading() :: binary()
+  @spec stop_loading() :: <<_::8>>
   def stop_loading(), do: <<@msg_stop_loading>>
 
-  @spec set_zoom(number()) :: binary()
+  @spec set_zoom(number()) :: <<_::8, _::_*8>>
   def set_zoom(factor) when is_number(factor) do
     str = to_string(factor)
     <<@msg_set_zoom, str::binary>>