1 files changed, 97 insertions, 0 deletions
diff --git a/activesupport/test/option_merger_test.rb b/activesupport/test/option_merger_test.rb
new file mode 100644
index 0000000000..935e2aee63
--- /dev/null
+++ b/activesupport/test/option_merger_test.rb
@@ -0,0 +1,97 @@
+# frozen_string_literal: true
+
+require "abstract_unit"
+require "active_support/core_ext/object/with_options"
+
+class OptionMergerTest < ActiveSupport::TestCase
+  def setup
+    @options = { hello: "world" }
+  end
+
+  def test_method_with_options_merges_options_when_options_are_present
+    local_options = { cool: true }
+
+    with_options(@options) do |o|
+      assert_equal local_options, method_with_options(local_options)
+      assert_equal @options.merge(local_options),
+        o.method_with_options(local_options)
+    end
+  end
+
+  def test_method_with_options_appends_options_when_options_are_missing
+    with_options(@options) do |o|
+      assert_equal Hash.new, method_with_options
+      assert_equal @options, o.method_with_options
+    end
+  end
+
+  def test_method_with_options_allows_to_overwrite_options
+    local_options = { hello: "moon" }
+    assert_equal @options.keys, local_options.keys
+
+    with_options(@options) do |o|
+      assert_equal local_options, method_with_options(local_options)
+      assert_equal @options.merge(local_options),
+        o.method_with_options(local_options)
+      assert_equal local_options, o.method_with_options(local_options)
+    end
+    with_options(local_options) do |o|
+      assert_equal local_options.merge(@options),
+        o.method_with_options(@options)
+    end
+  end
+
+  def test_nested_method_with_options_containing_hashes_merge
+    with_options conditions: { method: :get } do |outer|
+      outer.with_options conditions: { domain: "www" } do |inner|
+        expected = { conditions: { method: :get, domain: "www" } }
+        assert_equal expected, inner.method_with_options
+      end
+    end
+  end
+
+  def test_nested_method_with_options_containing_hashes_overwrite
+    with_options conditions: { method: :get, domain: "www" } do |outer|
+      outer.with_options conditions: { method: :post } do |inner|
+        expected = { conditions: { method: :post, domain: "www" } }
+        assert_equal expected, inner.method_with_options
+      end
+    end
+  end
+
+  def test_nested_method_with_options_containing_hashes_going_deep
+    with_options html: { class: "foo", style: { margin: 0, display: "block" } } do |outer|
+      outer.with_options html: { title: "bar", style: { margin: "1em", color: "#fff" } } do |inner|
+        expected = { html: { class: "foo", title: "bar", style: { margin: "1em", display: "block", color: "#fff" } } }
+        assert_equal expected, inner.method_with_options
+      end
+    end
+  end
+
+  def test_nested_method_with_options_using_lambda
+    local_lambda = lambda { { lambda: true } }
+    with_options(@options) do |o|
+      assert_equal @options.merge(local_lambda.call),
+        o.method_with_options(local_lambda).call
+    end
+  end
+
+  # Needed when counting objects with the ObjectSpace
+  def test_option_merger_class_method
+    assert_equal ActiveSupport::OptionMerger, ActiveSupport::OptionMerger.new("", "").class
+  end
+
+  def test_option_merger_implicit_receiver
+    @options.with_options foo: "bar" do
+      merge! fizz: "buzz"
+    end
+
+    expected = { hello: "world", foo: "bar", fizz: "buzz" }
+    assert_equal expected, @options
+  end
+
+  private
+    def method_with_options(options = {})
+      options
+    end
+end