feature: add except to IndifferentHash (#1940)

The method `Hash#except` [was added in Ruby
3.0](ruby/ruby@82ca8c7)
so it would be nice that calling `except` in a `Sinatra::IndifferentHash`
supported the indifferent access that the latter provides – right now,
calling `except(:a)` on `Sinatra::IndifferntHash[a: :a]` would not
filter the `a` key.

This commits adds indifferent access support to except so that it will
exclude the passed key independently if the key is passed as a `String`
or `Symbol`.

---------

Co-authored-by: Santiago Rodriguez <santiago.rodriguez@ext.airbnb.com>
Co-authored-by: Eloy Pérez <ej.perezgomez@gmail.com>

lib/sinatra/indifferent_hash.rb

@@ -186,6 +186,12 @@ def compact
       dup.tap(&:compact!)
     end
 
+    def except(*keys)
+      keys.map!(&method(:convert_key))
+
+      super(*keys)
+    end if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new("3.0")
+
     private
 
     def convert_key(key)

test/indifferent_hash_test.rb

@@ -291,4 +291,9 @@ def test_compact
     compacted_hash = non_empty_hash.compact
     assert_equal non_empty_hash, compacted_hash
   end
+
+  def test_except
+    hash = @hash.except(?b, 3, :simple_nested, 'nested')
+    assert_equal Sinatra::IndifferentHash[a: :a], hash
+  end if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new("3.0")
 end