Introduce `Headers#add`. Move `Response#add_header` upstream.

* Introduce `ActionDispatch::Http::Headers#add` to add a value to
  a multivalued header.
* Move `Response#add_header` upstream: https://github.com/rack/rack/pull/957
* Match upstream `Response#have_header?` -> `#has_header?` name change.

2 files changed, 28 insertions, 10 deletions

diff --git a/actionpack/test/dispatch/header_test.rb b/actionpack/test/dispatch/header_test.rb
index 79600b654b..7f1ef121b7 100644
--- a/actionpack/test/dispatch/header_test.rb
+++ b/actionpack/test/dispatch/header_test.rb
@@ -42,6 +42,24 @@ class HeaderTest < ActiveSupport::TestCase
     assert_equal "127.0.0.1", @headers["HTTP_HOST"]
   end
 
+  test "add to multivalued headers" do
+    # Sets header when not present
+    @headers.add 'Foo', '1'
+    assert_equal '1', @headers['Foo']
+
+    # Ignores nil values
+    @headers.add 'Foo', nil
+    assert_equal '1', @headers['Foo']
+
+    # Converts value to string
+    @headers.add 'Foo', 1
+    assert_equal '1,1', @headers['Foo']
+
+    # Case-insensitive
+    @headers.add 'fOo', 2
+    assert_equal '1,1,2', @headers['foO']
+  end
+
   test "headers can contain numbers" do
     @headers["Content-MD5"] = "Q2hlY2sgSW50ZWdyaXR5IQ=="
 
diff --git a/actionpack/test/dispatch/response_test.rb b/actionpack/test/dispatch/response_test.rb
index 82cc21b17a..2b2fea7504 100644
--- a/actionpack/test/dispatch/response_test.rb
+++ b/actionpack/test/dispatch/response_test.rb
@@ -299,10 +299,10 @@ class ResponseHeadersTest < ActiveSupport::TestCase
     @response.set_header 'Foo', '1'
   end
 
-  test 'have_header?' do
-    assert @response.have_header? 'Foo'
-    assert_not @response.have_header? 'foo'
-    assert_not @response.have_header? nil
+  test 'has_header?' do
+    assert @response.has_header? 'Foo'
+    assert_not @response.has_header? 'foo'
+    assert_not @response.has_header? nil
   end
 
   test 'get_header' do
@@ -313,11 +313,11 @@ class ResponseHeadersTest < ActiveSupport::TestCase
 
   test 'set_header' do
     assert_equal '2', @response.set_header('Foo', '2')
-    assert @response.have_header?('Foo')
+    assert @response.has_header?('Foo')
     assert_equal '2', @response.get_header('Foo')
 
     assert_nil @response.set_header('Foo', nil)
-    assert @response.have_header?('Foo')
+    assert @response.has_header?('Foo')
     assert_nil @response.get_header('Foo')
   end
 
@@ -325,10 +325,10 @@ class ResponseHeadersTest < ActiveSupport::TestCase
     assert_nil @response.delete_header(nil)
 
     assert_nil @response.delete_header('foo')
-    assert @response.have_header?('Foo')
+    assert @response.has_header?('Foo')
 
     assert_equal '1', @response.delete_header('Foo')
-    assert_not @response.have_header?('Foo')
+    assert_not @response.has_header?('Foo')
   end
 
   test 'add_header' do
@@ -342,12 +342,12 @@ class ResponseHeadersTest < ActiveSupport::TestCase
 
     # Add nil to a nonexistent header
     assert_nil @response.add_header('Bar', nil)
-    assert_not @response.have_header?('Bar')
+    assert_not @response.has_header?('Bar')
     assert_nil @response.get_header('Bar')
 
     # Add a value to a nonexistent header
     assert_equal '1', @response.add_header('Bar', '1')
-    assert @response.have_header?('Bar')
+    assert @response.has_header?('Bar')
     assert_equal '1', @response.get_header('Bar')
   end
 end