(PUP-11767) Changes for rubocop Style/AutoResourceCleanup

Prefer usage of `File.new` to `File.open` to differentiate when the
file object is expected to persist and stay open and to enable
AutoResourceCleanup entirely.

.rubocop.yml

@@ -199,3 +199,7 @@ RSpec/FactoryBot/SyntaxMethods: # new in 2.7
 
 RSpec/Rails/AvoidSetupHook: # new in 2.4
   Enabled: true
+
+Style/AutoResourceCleanup:
+  Enabled: true
+

lib/puppet/util/at_fork/solaris.rb

@@ -64,7 +64,7 @@ def raise_if_error(&block)
 
   def activate_new_contract_template
     begin
-      tmpl = File.open(CTFS_PR_TEMPLATE, File::RDWR)
+      tmpl = File.new(CTFS_PR_TEMPLATE, File::RDWR)
 
       begin
         tmpl_fd = tmpl.fileno
@@ -109,7 +109,7 @@ def deactivate_contract_template(parent)
 
   def get_latest_child_contract_id
     begin
-      stat = File.open(CTFS_PR_LATEST, File::RDONLY)
+      stat = File.new(CTFS_PR_LATEST, File::RDONLY)
 
       begin
         stathdl = Fiddle::Pointer.new(0)
@@ -133,7 +133,7 @@ def abandon_latest_child_contract
     return if ctid.nil?
 
     begin
-      ctl = File.open(File.join(CTFS_PR_ROOT, ctid.to_s, %q(ctl)), File::WRONLY)
+      ctl = File.new(File.join(CTFS_PR_ROOT, ctid.to_s, %q(ctl)), File::WRONLY)
 
       begin
         raise_if_error { ct_ctl_abandon(ctl.fileno) }

lib/puppet/util/log/destinations.rb

@@ -91,7 +91,7 @@ def initialize(path)
       end
     end
 
-    file = File.open(path, File::WRONLY | File::CREAT | File::APPEND)
+    file = File.new(path, File::WRONLY | File::CREAT | File::APPEND)
     file.puts('[') if need_array_start
 
     @file = file

lib/puppet/util/selinux.rb

@@ -242,7 +242,7 @@ def read_mounts
       if File.method_defined? "read_nonblock"
         # If possible we use read_nonblock in a loop rather than read to work-
         # a linux kernel bug.  See ticket #1963 for details.
-        mountfh = File.open("/proc/mounts")
+        mountfh = File.new("/proc/mounts")
         loop do
           mounts += mountfh.read_nonblock(1024)
         end

spec/unit/util/selinux_spec.rb

@@ -29,16 +29,16 @@
     end
 
     it "should return nil if /proc/mounts does not exist" do
-      allow(File).to receive(:open).with("/proc/mounts").and_raise("No such file or directory - /proc/mounts")
+      allow(File).to receive(:new).with("/proc/mounts").and_raise("No such file or directory - /proc/mounts")
       expect(read_mounts).to eq(nil)
     end
   end
 
   describe "read_mounts" do
     before :each do
       fh = double('fh', :close => nil)
-      allow(File).to receive(:open).and_call_original()
-      allow(File).to receive(:open).with("/proc/mounts").and_return(fh)
+      allow(File).to receive(:new).and_call_original()
+      allow(File).to receive(:new).with("/proc/mounts").and_return(fh)
       times_fh_called = 0
       expect(fh).to receive(:read_nonblock) do
         times_fh_called += 1
@@ -304,7 +304,7 @@
   describe "set_selinux_context" do
     before :each do
       fh = double('fh', :close => nil)
-      allow(File).to receive(:open).with("/proc/mounts").and_return(fh)
+      allow(File).to receive(:new).with("/proc/mounts").and_return(fh)
       times_fh_called = 0
       allow(fh).to receive(:read_nonblock) do
         times_fh_called += 1