// META: global=window,worker // META: title=Response: error static method test(function() { var responseError = Response.error(); assert_equals(responseError.type, "error", "Network error response's type is error"); assert_equals(responseError.status, 0, "Network error response's status is 0"); assert_equals(responseError.statusText, "", "Network error response's statusText is empty"); assert_equals(responseError.body, null, "Network error response's body is null"); assert_true(responseError.headers.entries().next().done, "Headers should be empty"); }, "Check response returned by static method error()"); test(function() { const headers = Response.error().headers; // Avoid false positives if expected API is not available assert_true(!!headers); assert_equals(typeof headers.append, 'function'); assert_throws_js(TypeError, function () { headers.append('name', 'value'); }); }, "the 'guard' of the Headers instance should be immutable");