1 files changed, 24 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/hash/except.rb b/activesupport/lib/active_support/core_ext/hash/except.rb
new file mode 100644
index 0000000000..6258610c98
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/hash/except.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class Hash
+  # Returns a hash that includes everything except given keys.
+  #   hash = { a: true, b: false, c: nil }
+  #   hash.except(:c)     # => { a: true, b: false }
+  #   hash.except(:a, :b) # => { c: nil }
+  #   hash                # => { a: true, b: false, c: nil }
+  #
+  # This is useful for limiting a set of parameters to everything but a few known toggles:
+  #   @person.update(params[:person].except(:admin))
+  def except(*keys)
+    dup.except!(*keys)
+  end
+
+  # Removes the given keys from hash and returns it.
+  #   hash = { a: true, b: false, c: nil }
+  #   hash.except!(:c) # => { a: true, b: false }
+  #   hash             # => { a: true, b: false }
+  def except!(*keys)
+    keys.each { |key| delete(key) }
+    self
+  end
+end