Use File.exist? instead of File.exists?

We've noticed the following warning while testing the upgrade to
Ruby 3.0:

warning: File.exists? is deprecated; use File.exist? instead

We're adding a Rubocop rule so we don't call the deprecated method
in the future.

.rubocop.yml

@@ -164,6 +164,9 @@ Lint/BooleanSymbol:
 Lint/ConstantDefinitionInBlock:
   Enabled: true
 
+Lint/DeprecatedClassMethods:
+  Enabled: true
+
 Lint/DuplicateBranch:
   Enabled: true
 

app/models/machine_learning.rb

@@ -95,14 +95,14 @@ class MachineLearning
     def data_output_files
       files = { tags: [], related_content: [], comments_summary: [] }
 
-      files[:tags] << proposals_tags_filename if File.exists?(data_folder.join(proposals_tags_filename))
-      files[:tags] << proposals_taggings_filename if File.exists?(data_folder.join(proposals_taggings_filename))
-      files[:tags] << investments_tags_filename if File.exists?(data_folder.join(investments_tags_filename))
-      files[:tags] << investments_taggings_filename if File.exists?(data_folder.join(investments_taggings_filename))
-      files[:related_content] << proposals_related_filename if File.exists?(data_folder.join(proposals_related_filename))
-      files[:related_content] << investments_related_filename if File.exists?(data_folder.join(investments_related_filename))
-      files[:comments_summary] << proposals_comments_summary_filename if File.exists?(data_folder.join(proposals_comments_summary_filename))
-      files[:comments_summary] << investments_comments_summary_filename if File.exists?(data_folder.join(investments_comments_summary_filename))
+      files[:tags] << proposals_tags_filename if File.exist?(data_folder.join(proposals_tags_filename))
+      files[:tags] << proposals_taggings_filename if File.exist?(data_folder.join(proposals_taggings_filename))
+      files[:tags] << investments_tags_filename if File.exist?(data_folder.join(investments_tags_filename))
+      files[:tags] << investments_taggings_filename if File.exist?(data_folder.join(investments_taggings_filename))
+      files[:related_content] << proposals_related_filename if File.exist?(data_folder.join(proposals_related_filename))
+      files[:related_content] << investments_related_filename if File.exist?(data_folder.join(investments_related_filename))
+      files[:comments_summary] << proposals_comments_summary_filename if File.exist?(data_folder.join(proposals_comments_summary_filename))
+      files[:comments_summary] << investments_comments_summary_filename if File.exist?(data_folder.join(investments_comments_summary_filename))
 
       files
     end
@@ -438,13 +438,13 @@ class MachineLearning
     end
 
     def last_modified_date_for(filename)
-      return nil unless File.exists? data_folder.join(filename)
+      return nil unless File.exist? data_folder.join(filename)
 
       File.mtime data_folder.join(filename)
     end
 
     def updated_file?(filename)
-      return false unless File.exists? data_folder.join(filename)
+      return false unless File.exist? data_folder.join(filename)
       return true unless previous_modified_date[filename].present?
 
       last_modified_date_for(filename) > previous_modified_date[filename]

spec/lib/tasks/files_spec.rb

@@ -18,8 +18,8 @@ describe "files tasks" do
 
       travel_to(2.days.from_now) { run_rake_task }
 
-      expect(File.exists?(image.file_path)).to be false
-      expect(File.exists?(document.file_path)).to be false
+      expect(File.exist?(image.file_path)).to be false
+      expect(File.exist?(document.file_path)).to be false
     end
 
     it "does not delete recent cached attachments" do
@@ -33,8 +33,8 @@ describe "files tasks" do
 
       travel_to(2.minutes.from_now) { run_rake_task }
 
-      expect(File.exists?(image.file_path)).to be true
-      expect(File.exists?(document.file_path)).to be true
+      expect(File.exist?(image.file_path)).to be true
+      expect(File.exist?(document.file_path)).to be true
     end
 
     it "does not delete old regular attachments" do
@@ -43,8 +43,8 @@ describe "files tasks" do
 
       travel_to(2.days.from_now) { run_rake_task }
 
-      expect(File.exists?(image.file_path)).to be true
-      expect(File.exists?(document.file_path)).to be true
+      expect(File.exist?(image.file_path)).to be true
+      expect(File.exist?(document.file_path)).to be true
     end
   end
 end