USe compile-time environment checks

config/dev.exs

@@ -72,6 +72,12 @@ config :philomena, PhilomenaWeb.Endpoint,
     ]
   ]
 
+# Relax CSP rules in development
+config :philomena, csp_relaxed: true
+
+# Enable Vite HMR
+config :philomena, vite_reload: true
+
 # Do not include metadata nor timestamps in development logs
 config :logger, :console, format: "[$level] $message\n"
 

config/runtime.exs

@@ -134,22 +134,10 @@ if config_env() == :prod do
     url: [host: System.fetch_env!("APP_HOSTNAME"), scheme: "https", port: 443],
     secret_key_base: System.fetch_env!("SECRET_KEY_BASE"),
     server: not is_nil(System.get_env("START_ENDPOINT"))
-
-  # Do not relax CSP in production
-  config :philomena, csp_relaxed: false
-
-  # Disable Vite HMR in prod
-  config :philomena, vite_reload: false
 else
   # Don't send email in development
   config :philomena, Philomena.Mailer, adapter: Bamboo.LocalAdapter
 
   # Use this to debug slime templates
   # config :slime, :keep_lines, true
-
-  # Relax CSP rules in development and test servers
-  config :philomena, csp_relaxed: true
-
-  # Enable Vite HMR
-  config :philomena, vite_reload: true
 end

lib/philomena_web/config.ex

@@ -0,0 +1,12 @@
+defmodule PhilomenaWeb.Config do
+  @reload_enabled Application.compile_env(:philomena, :vite_reload, false)
+  @csp_relaxed Application.compile_env(:philomena, :csp_relaxed, false)
+
+  defmacro vite_hmr?(do: do_clause, else: else_clause) do
+    if(@reload_enabled, do: do_clause, else: else_clause)
+  end
+
+  defmacro csp_relaxed?(do: do_clause, else: else_clause) do
+    if(@csp_relaxed, do: do_clause, else: else_clause)
+  end
+end

lib/philomena_web/plugs/content_security_policy_plug.ex

@@ -1,4 +1,5 @@
 defmodule PhilomenaWeb.ContentSecurityPolicyPlug do
+  import PhilomenaWeb.Config
   import Plug.Conn
 
   @allowed_sources [
@@ -42,13 +43,17 @@ defmodule PhilomenaWeb.ContentSecurityPolicyPlug do
         |> Enum.map(&cspify_element/1)
         |> Enum.join("; ")
 
-      if conn.status == 500 and allow_relaxed_csp() do
+      csp_relaxed? do
+        if conn.status == 500 do
           # Allow Plug.Debugger to function in this case
           delete_resp_header(conn, "content-security-policy")
         else
           # Enforce CSP otherwise
           put_resp_header(conn, "content-security-policy", csp_value)
         end
+      else
+        put_resp_header(conn, "content-security-policy", csp_value)
+      end
     end)
   end
 
@@ -64,14 +69,13 @@ defmodule PhilomenaWeb.ContentSecurityPolicyPlug do
 
   defp cdn_uri, do: Application.get_env(:philomena, :cdn_host) |> to_uri()
   defp camo_uri, do: Application.get_env(:philomena, :camo_host) |> to_uri()
-  defp vite_reload?, do: Application.get_env(:philomena, :vite_reload)
 
-  defp default_script_src, do: if(vite_reload?(), do: "'self' localhost:5173", else: "'self'")
+  defp default_script_src, do: vite_hmr?(do: "'self' localhost:5173", else: "'self'")
 
   defp default_connect_src,
-    do: if(vite_reload?(), do: "'self' localhost:5173 ws://localhost:5173", else: "'self'")
+    do: vite_hmr?(do: "'self' localhost:5173 ws://localhost:5173", else: "'self'")
 
-  defp default_style_src, do: if(vite_reload?(), do: "'self' 'unsafe-inline'", else: "'self'")
+  defp default_style_src, do: vite_hmr?(do: "'self' 'unsafe-inline'", else: "'self'")
 
   defp to_uri(host) when host in [nil, ""], do: ""
   defp to_uri(host), do: URI.to_string(%URI{scheme: "https", host: host})
@@ -84,6 +88,4 @@ defmodule PhilomenaWeb.ContentSecurityPolicyPlug do
 
     Enum.join([key | value], " ")
   end
-
-  defp allow_relaxed_csp, do: Application.get_env(:philomena, :csp_relaxed, false)
 end

lib/philomena_web/templates/layout/app.html.slime

@@ -20,7 +20,7 @@ html lang="en"
     meta name="format-detection" content="telephone=no"
     = csrf_meta_tag()
 
-    = if vite_reload?() do
+    = vite_hmr? do
       script type="module" src="http://localhost:5173/@vite/client"
       script type="module" src="http://localhost:5173/js/app.js"
     - else

lib/philomena_web/views/layout_view.ex

@@ -1,6 +1,7 @@
 defmodule PhilomenaWeb.LayoutView do
   use PhilomenaWeb, :view
 
+  import PhilomenaWeb.Config
   alias PhilomenaWeb.ImageView
   alias Philomena.Config
   alias Plug.Conn