Merge pull request rails#20125

Manually merged to fix conflicts.

Author: sgrif

activesupport/CHANGELOG.md

@@ -1,3 +1,10 @@
+*   ActiveSupport::HashWithIndifferentAccess `select` and `reject` will now return
+    enumerator if called without block.
+
+    Fixes #20095
+
+    *Bernard Potocki*
+
 *   Removed `ActiveSupport::Concurrency::Latch`, superseded by `Concurrent::CountDownLatch`
     from the concurrent-ruby gem.
 

activesupport/lib/active_support/hash_with_indifferent_access.rb

@@ -238,10 +238,12 @@ def deep_symbolize_keys; to_hash.deep_symbolize_keys! end
     def to_options!; self end
 
     def select(*args, &block)
+      return to_enum(:select) unless block_given?
       dup.tap { |hash| hash.select!(*args, &block) }
     end
 
     def reject(*args, &block)
+      return to_enum(:reject) unless block_given?
       dup.tap { |hash| hash.reject!(*args, &block) }
     end
 

activesupport/test/core_ext/hash_ext_test.rb

@@ -551,6 +551,11 @@ def test_indifferent_select
     assert_instance_of ActiveSupport::HashWithIndifferentAccess, hash
   end
 
+  def test_indifferent_select_returns_enumerator
+    enum = ActiveSupport::HashWithIndifferentAccess.new(@strings).select
+    assert_instance_of Enumerator, enum
+  end
+
   def test_indifferent_select_returns_a_hash_when_unchanged
     hash = ActiveSupport::HashWithIndifferentAccess.new(@strings).select {|k,v| true}
 
@@ -572,6 +577,11 @@ def test_indifferent_reject
     assert_instance_of ActiveSupport::HashWithIndifferentAccess, hash
   end
 
+  def test_indifferent_reject_returns_enumerator
+    enum = ActiveSupport::HashWithIndifferentAccess.new(@strings).reject
+    assert_instance_of Enumerator, enum
+  end
+
   def test_indifferent_reject_bang
     indifferent_strings = ActiveSupport::HashWithIndifferentAccess.new(@strings)
     indifferent_strings.reject! {|k,v| v != 1}