Silence parser warnings (#18429)

Gemfile

@@ -108,6 +108,7 @@ gem "twitter", "~> 7.0" # A Ruby interface to the Twitter API
 gem "uglifier", "~> 4.2" # Uglifier minifies JavaScript files
 gem "validate_url", "~> 1.0" # Library for validating urls in Rails
 gem "vault", "~> 0.17" # Used to store secrets
+gem "warning", "~> 1.3" # Adds custom processing for warnings, including the ability to ignore specific warning messages
 gem "wcag_color_contrast", "~> 0.1" # Detect contrast of colors to determine readability and a11y.
 gem "webpacker", "~> 5.4.3" # Use webpack to manage app-like JavaScript modules in Rails
 

Gemfile.lock

@@ -902,6 +902,7 @@ GEM
     vcr (6.1.0)
     warden (1.2.9)
       rack (>= 2.0.9)
+    warning (1.3.0)
     wcag_color_contrast (0.1.0)
     web-console (4.2.0)
       actionview (>= 6.0.0)
@@ -1094,6 +1095,7 @@ DEPENDENCIES
   validate_url (~> 1.0)
   vault (~> 0.17)
   vcr (~> 6.1)
+  warning (~> 1.3)
   wcag_color_contrast (~> 0.1)
   web-console (~> 4.2)
   webdrivers (~> 5.0)

bin/setup

@@ -30,7 +30,7 @@ FileUtils.chdir APP_ROOT do
     FileUtils.cp "config/database.yml.sample", "config/database.yml"
   end
 
-  unless File.exists?(".env")
+  unless File.exist?(".env")
     FileUtils.cp ".env_sample", ".env"
   end
 

config/initializers/0_application_config.rb

@@ -1,3 +1,13 @@
+# NOTE: We need to ignore this warning early during app startup.
+# 1. `parser` is a transitive dependency (`erb_lint` -> `better_html` -> `parser`)
+# 2. The warnings are generated while reading the class body, so we need to ignore
+#    them *before* the gem's code is read.
+# 3. The warning is intentional, it will always occur when the used point release
+#    isn't the most recent. Since our update schedule is somewhat influenced by
+#    Fedora release cycles right now, this can occur frequently.
+require "warning"
+Warning.ignore(%r{parser/current})
+
 class ApplicationConfig
   URI_REGEXP = %r{(?<scheme>https?://)?(?<host>.+?)(?<port>:\d+)?$}