Skip eval and avoid generating all generators inside of the benchmark execution

Looping over the constants instead of using `eval` is a more secure approach.
Plus, build the list of generators outside so that we're only benchmarking generator execution.

Co-Authored-By: Thiago Araujo <thd.araujo@gmail.com>

Author: stefannibrasil

.rubocop.yml

@@ -54,7 +54,6 @@ Security/Eval:
   Description: The use of eval represents a serious security risk.
   Exclude:
     - 'lib/faker/default/json.rb'
-    - 'benchmark/generators.rb'
 
 Style/AsciiComments:
   Description: This cop checks for non-ascii (non-English) characters in comments.
@@ -77,7 +76,6 @@ Style/EvalWithLocation:
   Description: This cop checks eval method usage. eval can receive source location metadata, that are filename and line number.
   Exclude:
     - 'lib/faker/default/json.rb'
-    - 'benchmark/generators.rb'
 
 Style/FormatStringToken:
   Description: This cop checks for a consistent style for named format string tokens.

benchmark/generators.rb

@@ -3,13 +3,13 @@
 require 'benchmark/ips'
 require 'faker'
 
-def all_generators
-  generators.map do |klass|
-    subclass_methods(klass).flatten
-  end.flatten.sort
+def generators
+  constants.flat_map do |klass|
+    subclass_methods(klass)
+  end
 end
 
-def generators
+def constants
   Faker.constants.delete_if do |subclass|
     %i[
       Base
@@ -28,13 +28,19 @@ def generators
 end
 
 def subclass_methods(subclass)
-  eval("Faker::#{subclass}.public_methods(false) - Faker::Base.public_methods(false)").sort.map do |method|
-    "Faker::#{subclass}.#{method}"
-  end.sort
+  klass = Faker.const_get(subclass)
+
+  public_methods = klass.public_methods(false) - Faker::Base.public_methods(false)
+
+  public_methods.sort.map do |method|
+    [klass, method]
+  end
 end
 
+all_generators = generators
+
 Benchmark.ips do |x|
   x.report("Number of generators: #{all_generators.count}") do
-    all_generators.each { |generator| eval(generator) }
+    all_generators.each { |klass, generator| klass.send(generator) }
   end
 end