From dd390407bec248cd69aadb17e0d6f442a8a70829 Mon Sep 17 00:00:00 2001
From: Martin Jones <martin.jones@digital.cabinet-office.gov.uk>
Date: Wed, 1 May 2024 11:00:12 +0100
Subject: [PATCH] Move from Uglifier to Terser

govuk_publishing_components has govuk-frontend as a dependency.

govuk-frontend v5 now targets browsers that support ES6. This means that the UMD modules used in govuk_publsihing_components from govuk-frontend use features of ES6 and so it means that Uglifier can't be used anymore because it only supports ES5.
---
 Gemfile                           | 2 +-
 Gemfile.lock                      | 8 ++++----
 config/environments/production.rb | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Gemfile b/Gemfile
index 403a4f2e..bcb84149 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,7 +15,7 @@ gem "plek"
 gem "ratelimit"
 gem "slimmer"
 gem "sprockets-rails"
-gem "uglifier"
+gem "terser"
 
 group :development, :test do
   gem "climate_control"
diff --git a/Gemfile.lock b/Gemfile.lock
index 0579903c..7f750e1b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -111,7 +111,7 @@ GEM
     domain_name (0.6.20240107)
     drb (2.2.1)
     erubi (1.12.0)
-    execjs (2.8.1)
+    execjs (2.9.1)
     gds-api-adapters (95.1.0)
       addressable
       link_header
@@ -603,13 +603,13 @@ GEM
       sprockets (>= 3.0.0)
     statsd-ruby (1.5.0)
     stringio (3.1.0)
+    terser (1.2.2)
+      execjs (>= 0.3.0, < 3)
     thor (1.3.1)
     timecop (0.9.8)
     timeout (0.4.1)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    uglifier (4.2.0)
-      execjs (>= 0.3.0, < 3)
     unicode-display_width (2.5.0)
     webmock (3.23.0)
       addressable (>= 2.8.0)
@@ -651,8 +651,8 @@ DEPENDENCIES
   simplecov
   slimmer
   sprockets-rails
+  terser
   timecop
-  uglifier
   webmock
 
 RUBY VERSION
diff --git a/config/environments/production.rb b/config/environments/production.rb
index dda10ef9..b4ae8dc5 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -25,7 +25,7 @@
   config.public_file_server.enabled = false
 
   # Compress JS using a preprocessor.
-  config.assets.js_compressor = :uglifier
+  config.assets.js_compressor = :terser
 
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false