Replace obsolete file size conversion gem with local code

Gemfile

@@ -54,8 +54,6 @@ end
 # Use honeybadger for exception handling
 gem 'honeybadger'
 
-gem 'filesize'
-
 gem 'newrelic_rpm', group: :production
 
 # Use okcomputer to monitor the application

Gemfile.lock

@@ -158,7 +158,6 @@ GEM
       faraday (>= 1, < 3)
     faraday-net_http (3.1.0)
       net-http
-    filesize (0.2.0)
     globalid (1.2.1)
       activesupport (>= 6.1)
     hashdiff (1.1.0)
@@ -400,7 +399,6 @@ DEPENDENCIES
   factory_bot_rails (~> 6.4)
   faraday (~> 2)
   faraday-follow_redirects
-  filesize
   high_voltage
   honeybadger
   importmap-rails (~> 2.0)

config/locales/en.yml

@@ -20,14 +20,18 @@
 # available at http://guides.rubyonrails.org/i18n.html.
 
 en:
-  hello: "Hello world"
   restrictions:
     not_accessible: 'This item cannot be accessed online. See Access conditions for more information.'
     logged_in: 'Logged in.'
   date:
     formats:
       sul: '%d-%b-%Y'
       sul_was_long: '%d %B %Y'
+  number:
+    human:
+      storage_units:
+        units:
+          kb: kB # This is the SI unit for 10^3
   viewers:
     file:
       title: 'File viewer'

lib/embed/pretty_filesize.rb

@@ -9,7 +9,7 @@ module PrettyFilesize
     # @param [String] size the file size in bytes
     # @return [String] a human readable representation in SI units
     def pretty_filesize(size)
-      Filesize.new("#{size} B", Filesize::SI).pretty
+      SizeConverter.new(size, { base: 1000, precision: 2, significant: false }).convert
     end
   end
 end

lib/size_converter.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+# Override Rails provided converter to handle SI units.
+class SizeConverter < ActiveSupport::NumberHelper::NumberToHumanSizeConverter
+  private
+
+  # Allows a base to be specified for the conversion
+  # 1024 was the default and that produces gigibytes
+  # 1000 produces gigabytes
+  def base
+    options[:base] || 1000
+  end
+end

spec/features/file_viewer_spec.rb

@@ -25,7 +25,7 @@
 
       expect(page).to have_css('tr[data-tree-role="leaf"] a', text: 'Download')
       expect(page).to have_css('*[data-tree-role="label"]', text: 'File1 Label')
-      expect(page).to have_css('td', text: '12.34 kB')
+      expect(page).to have_css('td', text: '12.35 kB')
     end
 
     context 'when the object has multiple files' do

spec/lib/embed/pretty_filesize_spec.rb

@@ -11,12 +11,7 @@
     context 'kilobyte scale' do
       let(:size) { 12_345 }
 
-      if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.4.0')
-        # Gaussian rounding: https://blog.heroku.com/ruby-2-4-features-hashes-integers-rounding#gaussian-rounding
-        it { is_expected.to eq '12.34 kB' }
-      else
-        it { is_expected.to eq '12.35 kB' }
-      end
+      it { is_expected.to eq '12.35 kB' }
     end
 
     context 'megabyte scale' do