[Fetch API] Appending headers of the same name should have their values

third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/headers.js

Index: third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/headers.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/headers.js b/third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/headers.js
index d9af65cfb6029d13d5fe5df46edb80697838f33f..8fee4c3eb28c474e607c3e420e4d6528dc8deace 100644
--- a/third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/headers.js
+++ b/third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/headers.js
@@ -136,7 +136,7 @@ test(function() {
     headers.append('X-FETCH-TEST-2', 'response test field - append');
     assert_equals(size(headers), 5, 'headers size should increase by 1.');
     assert_equals(headers.get('X-FETCH-Test'),
-                  'response test field - updated',
+                  'response test field - updated,response test field - append',
                   'the value of the first header added should be returned.');
     allValues = headers.getAll('X-FETch-TEST');
     assert_equals(allValues.length, 2);
@@ -156,7 +156,7 @@ test(function() {
     headers = new Headers([['a', 'b'], ['c', 'd'], ['c', 'e']]);
     assert_equals(size(headers), 2, 'headers size should match');
     assert_equals(headers.get('a'), 'b');
-    assert_equals(headers.get('c'), 'd');
+    assert_equals(headers.get('c'), 'd,e');
     assert_equals(headers.getAll('c')[0], 'd');
     assert_equals(headers.getAll('c')[1], 'e');
 
@@ -164,13 +164,18 @@ test(function() {
     var headers2 = new Headers(headers);
     assert_equals(size(headers2), 2, 'headers size should match');
     assert_equals(headers2.get('a'), 'b');
-    assert_equals(headers2.get('c'), 'd');
+    assert_equals(headers2.get('c'), 'd,e');
     assert_equals(headers2.getAll('c')[0], 'd');
     assert_equals(headers2.getAll('c')[1], 'e');
     headers.set('a', 'x');
     assert_equals(headers.get('a'), 'x');
     assert_equals(headers2.get('a'), 'b');
 
+    var headers3 = new Headers();
+    headers3.append('test', 'a');
+    headers3.append('test', '');

[jsbell, 2016/12/16 22:29:37]

Hrm... I think this should throw TypeError:

https://fetch.spec.whatwg.org/#concept-headers-append

"If name is not a name or value is not a value, then throw a TypeError."

https://fetch.spec.whatwg.org/#concept-header-value

"A value is a byte sequence that matches the field-content token production."

https://tools.ietf.org/html/rfc7230#section-3.2

field-content  = field-vchar [ 1*( SP / HTAB ) field-vchar ]
field-vchar    = VCHAR / obs-text

... which seems to me that it must be non-empty.

+    headers3.append('test', 'b');
+    assert_equals(headers3.get('test'), 'a,b');
     // new Headers with Dictionary
     headers = new Headers({'a': 'b', 'c': 'd'});
     assert_equals(size(headers), 2, 'headers size should match');