(PUP-11974) Only warn when Ruby's verbose is enabled

In ruby 2.7.x, the rb_file_exists_p and rb_dir_exists_p methods call
rb_warning to log that the methods are deprecated[1][2] However, the
rb_warning method is a noop if $VERBOSE is nil or false[3] To preserve
the same behavior, only warn when $VERBOSE is truthy. Also include the
class name and path in the warning so we can identify and fix the issue.

[1] https://github.com/ruby/ruby/blob/1f4d4558484b370999954f3ede7e3aa3a3a01ef3/file.c#L1819
[2] https://github.com/ruby/ruby/blob/1f4d4558484b370999954f3ede7e3aa3a3a01ef3/dir.c#L3301
[3] https://github.com/ruby/ruby/blob/1f4d4558484b370999954f3ede7e3aa3a3a01ef3/error.c#L336-L338

Author: joshcooper

lib/puppet/util/monkey_patches.rb

@@ -33,7 +33,7 @@ def daemonize
 unless Dir.singleton_methods.include?(:exists?)
   class Dir
     def self.exists?(file_name)
-      warn('exists? is a deprecated name, use exist? instead')
+      warn("Dir.exists?('#{file_name}') is deprecated, use Dir.exist? instead") if $VERBOSE
       Dir.exist?(file_name)
     end
   end
@@ -42,7 +42,7 @@ def self.exists?(file_name)
 unless File.singleton_methods.include?(:exists?)
   class File
     def self.exists?(file_name)
-      warn('exists? is a deprecated name, use exist? instead')
+      warn("File.exists?('#{file_name}') is deprecated, use File.exist? instead") if $VERBOSE
       File.exist?(file_name)
     end
   end

spec/lib/puppet_spec/verbose.rb

@@ -1,9 +1,18 @@
-# Support code for running stuff with warnings disabled.
+# Support code for running stuff with warnings disabled or enabled
 module Kernel
   def with_verbose_disabled
     verbose, $VERBOSE = $VERBOSE, nil
     result = yield
     $VERBOSE = verbose
     return result
   end
+
+  def with_verbose_enabled
+    verbose, $VERBOSE = $VERBOSE, true
+    begin
+      yield
+    ensure
+      $VERBOSE = verbose
+    end
+  end
 end

spec/unit/agent_spec.rb

@@ -15,19 +15,12 @@ def stop
   end
 end
 
-def without_warnings
-  flag = $VERBOSE
-  $VERBOSE = nil
-  yield
-  $VERBOSE = flag
-end
-
 describe Puppet::Agent do
   before do
     @agent = Puppet::Agent.new(AgentTestClient, false)
 
     # make Puppet::Application safe for stubbing; restore in an :after block; silence warnings for this.
-    without_warnings { Puppet::Application = Class.new(Puppet::Application) }
+    with_verbose_disabled { Puppet::Application = Class.new(Puppet::Application) }
     allow(Puppet::Application).to receive(:clear?).and_return(true)
     Puppet::Application.class_eval do
       class << self
@@ -44,7 +37,7 @@ def controlled_run(&block)
 
   after do
     # restore Puppet::Application from stub-safe subclass, and silence warnings
-    without_warnings { Puppet::Application = Puppet::Application.superclass }
+    with_verbose_disabled { Puppet::Application = Puppet::Application.superclass }
   end
 
   it "should set its client class at initialization" do

spec/unit/util/monkey_patches_spec.rb

@@ -12,10 +12,12 @@
       expect(Dir.exists?(__dir__)).to be true
     end
 
-    if RUBY_VERSION >= '3.2' 
+    if RUBY_VERSION >= '3.2'
       it 'logs a warning message' do
-        expect(Dir).to receive(:warn).with('exists? is a deprecated name, use exist? instead')
-        Dir.exists?(__dir__)
+        expect(Dir).to receive(:warn).with("Dir.exists?('#{__dir__}') is deprecated, use Dir.exist? instead")
+        with_verbose_enabled do
+          Dir.exists?(__dir__)
+        end
       end
     end
   end
@@ -33,8 +35,10 @@
 
     if RUBY_VERSION >= '3.2'
       it 'logs a warning message' do
-        expect(File).to receive(:warn).with('exists? is a deprecated name, use exist? instead')
-        File.exists?(__FILE__)
+        expect(File).to receive(:warn).with("File.exists?('#{__FILE__}') is deprecated, use File.exist? instead")
+        with_verbose_enabled do
+          File.exists?(__FILE__)
+        end
       end
     end
   end