Upgrade to rails 5.2. Catch null state in percentage_for method

Gemfile

@@ -8,7 +8,7 @@ end
 
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-gem 'rails', '~> 5.1.7'
+gem 'rails', '~> 5.2.6'
 
 gem 'pg'
 

Gemfile.lock

@@ -10,48 +10,52 @@ GIT
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (5.1.7)
-      actionpack (= 5.1.7)
+    actioncable (5.2.6)
+      actionpack (= 5.2.6)
       nio4r (~> 2.0)
-      websocket-driver (~> 0.6.1)
-    actionmailer (5.1.7)
-      actionpack (= 5.1.7)
-      actionview (= 5.1.7)
-      activejob (= 5.1.7)
+      websocket-driver (>= 0.6.1)
+    actionmailer (5.2.6)
+      actionpack (= 5.2.6)
+      actionview (= 5.2.6)
+      activejob (= 5.2.6)
       mail (~> 2.5, >= 2.5.4)
       rails-dom-testing (~> 2.0)
-    actionpack (5.1.7)
-      actionview (= 5.1.7)
-      activesupport (= 5.1.7)
-      rack (~> 2.0)
+    actionpack (5.2.6)
+      actionview (= 5.2.6)
+      activesupport (= 5.2.6)
+      rack (~> 2.0, >= 2.0.8)
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (5.1.7)
-      activesupport (= 5.1.7)
+    actionview (5.2.6)
+      activesupport (= 5.2.6)
       builder (~> 3.1)
       erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activejob (5.1.7)
-      activesupport (= 5.1.7)
+    activejob (5.2.6)
+      activesupport (= 5.2.6)
       globalid (>= 0.3.6)
-    activemodel (5.1.7)
-      activesupport (= 5.1.7)
-    activerecord (5.1.7)
-      activemodel (= 5.1.7)
-      activesupport (= 5.1.7)
-      arel (~> 8.0)
+    activemodel (5.2.6)
+      activesupport (= 5.2.6)
+    activerecord (5.2.6)
+      activemodel (= 5.2.6)
+      activesupport (= 5.2.6)
+      arel (>= 9.0)
     activerecord-import (1.2.0)
       activerecord (>= 3.2)
-    activesupport (5.1.7)
+    activestorage (5.2.6)
+      actionpack (= 5.2.6)
+      activerecord (= 5.2.6)
+      marcel (~> 1.0.0)
+    activesupport (5.2.6)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
     addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
-    arel (8.0.0)
+    arel (9.0.0)
     autoprefixer-rails (10.3.3.0)
       execjs (~> 2)
     bcrypt (3.1.16)
@@ -120,19 +124,14 @@ GEM
       nokogiri (>= 1.5.9)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
+    marcel (1.0.2)
     method_source (1.0.0)
     mini_mime (1.1.2)
-    mini_portile2 (2.6.1)
     minitest (5.14.4)
     multi_json (1.15.0)
     nested_scaffold (1.1.0)
     newrelic_rpm (8.0.0)
     nio4r (2.5.8)
-    nokogiri (1.12.5)
-      mini_portile2 (~> 2.6.1)
-      racc (~> 1.4)
-    nokogiri (1.12.5-x86_64-darwin)
-      racc (~> 1.4)
     nokogiri (1.12.5-x86_64-linux)
       racc (~> 1.4)
     omniauth (2.0.4)
@@ -150,17 +149,18 @@ GEM
       rack
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
-    rails (5.1.7)
-      actioncable (= 5.1.7)
-      actionmailer (= 5.1.7)
-      actionpack (= 5.1.7)
-      actionview (= 5.1.7)
-      activejob (= 5.1.7)
-      activemodel (= 5.1.7)
-      activerecord (= 5.1.7)
-      activesupport (= 5.1.7)
+    rails (5.2.6)
+      actioncable (= 5.2.6)
+      actionmailer (= 5.2.6)
+      actionpack (= 5.2.6)
+      actionview (= 5.2.6)
+      activejob (= 5.2.6)
+      activemodel (= 5.2.6)
+      activerecord (= 5.2.6)
+      activestorage (= 5.2.6)
+      activesupport (= 5.2.6)
       bundler (>= 1.3.0)
-      railties (= 5.1.7)
+      railties (= 5.2.6)
       sprockets-rails (>= 2.0.0)
     rails-controller-testing (1.0.5)
       actionpack (>= 5.0.1.rc1)
@@ -171,12 +171,12 @@ GEM
       nokogiri (>= 1.6)
     rails-html-sanitizer (1.4.2)
       loofah (~> 2.3)
-    railties (5.1.7)
-      actionpack (= 5.1.7)
-      activesupport (= 5.1.7)
+    railties (5.2.6)
+      actionpack (= 5.2.6)
+      activesupport (= 5.2.6)
       method_source
       rake (>= 0.8.7)
-      thor (>= 0.18.1, < 2.0)
+      thor (>= 0.19.0, < 2.0)
     rake (13.0.6)
     rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
@@ -247,15 +247,13 @@ GEM
       activemodel (>= 5.0)
       bindex (>= 0.4.0)
       railties (>= 5.0)
-    websocket-driver (0.6.5)
+    websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
 
 PLATFORMS
-  ruby
-  x86_64-darwin-20
   x86_64-linux
 
 DEPENDENCIES
@@ -278,7 +276,7 @@ DEPENDENCIES
   omniauth
   pg
   puma (~> 3.0)
-  rails (~> 5.1.7)
+  rails (~> 5.2.6)
   rails-controller-testing
   rspec-rails (~> 4.1.2)
   sassc-rails

app/presenters/gauge_presenter.rb

@@ -27,8 +27,10 @@ class GaugePresenter
   end
 
   def percentage_for(number)
+    number ||= 0
     scale_minimum = @scale.warning_zone.low_benchmark
     scale_maximum = @scale.ideal_zone.high_benchmark
+
     (number - scale_minimum) / (scale_maximum - scale_minimum)
   end
 end