// META: title=Request ETag // META: global=window,worker // META: script=/common/utils.js promise_test(function() { var cacheBuster = token(); // ensures first request is uncached var url = "../resources/cache.py?v=" + cacheBuster; var etag; // make the first request return fetch(url).then(function(response) { // ensure we're getting the regular, uncached response assert_equals(response.status, 200); assert_equals(response.headers.get("X-HTTP-STATUS"), null) return response.text(); // consuming the body, just to be safe }).then(function(body) { // make a second request return fetch(url); }).then(function(response) { // while the server responds with 304 if our browser sent the correct // If-None-Match request header, at the JavaScript level this surfaces // as 200 assert_equals(response.status, 200); assert_equals(response.headers.get("X-HTTP-STATUS"), "304") etag = response.headers.get("ETag") return response.text(); // consuming the body, just to be safe }).then(function(body) { // make a third request, explicitly setting If-None-Match request header var headers = { "If-None-Match": etag } return fetch(url, { headers: headers }) }).then(function(response) { // 304 now surfaces thanks to the explicit If-None-Match request header assert_equals(response.status, 304); }); }, "Testing conditional GET with ETags");