util/rubocop -A --only Style/MultipleComparison

lib/rubygems/doctor.rb

@@ -103,7 +103,7 @@ class Gem::Doctor
     directory = File.join(@gem_repository, sub_directory)
 
     Dir.entries(directory).sort.each do |ent|
-      next if ent == "." || ent == ".."
+      next if [".", ".."].include?(ent)
 
       child = File.join(directory, ent)
       next unless File.exist?(child)

lib/rubygems/gemcutter_utilities.rb

@@ -297,7 +297,7 @@ module Gem::GemcutterUtilities
   def get_mfa_params(profile)
     mfa_level = profile["mfa"]
     params = {}
-    if mfa_level == "ui_only" || mfa_level == "ui_and_gem_signin"
+    if ["ui_only", "ui_and_gem_signin"].include?(mfa_level)
       selected = ask_yes_no("Would you like to enable MFA for this key? (strongly recommended)")
       params["mfa"] = true if selected
     end

lib/rubygems/request.rb

@@ -171,7 +171,7 @@ class Gem::Request
     no_env_proxy = env_proxy.nil? || env_proxy.empty?
 
     if no_env_proxy
-      return _scheme == "https" || _scheme == "http" ?
+      return ["https", "http"].include?(_scheme) ?
         :no_proxy : get_proxy_from_env("http")
     end
 

lib/rubygems/specification_policy.rb

@@ -193,7 +193,7 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
           prerelease_dep && !@specification.version.prerelease?
 
       open_ended = dep.requirement.requirements.all? do |op, version|
-        !version.prerelease? && (op == ">" || op == ">=")
+        !version.prerelease? && [">", ">="].include?(op)
       end
 
       if open_ended
@@ -203,7 +203,7 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
 
         base = segments.first 2
 
-        recommendation = if (op == ">" || op == ">=") && segments == [0]
+        recommendation = if [">", ">="].include?(op) && segments == [0]
           "  use a bounded requirement, such as '~> x.y'"
         else
           bugfix = if op == ">"