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Test Info:

<!doctype html>
<title>XMLHttpRequest: progress events and GZIP encoding</title>
<meta name="timeout" content="long">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<link rel="help" href="" data-tested-assertations="following::p[contains(text(),'content-encodings')]" />
<!-- TODO: find better spec reference when is fixed -->
<div id="log"></div>
var test = async_test()
test.step(function() {
var client = new XMLHttpRequest()
Two behaviours are considered acceptable, so there are two ways to
pass this test
a) Set data for the compressed resource:
* reflects the Content-length of the gzipp'ed resource
* event.loaded how many gzipped bytes have arrived over the wire so far
* lengthComputable is true
b) If the implementation does not provide progress details for the compressed
resource, set
* lengthComputable to false
* to 0
* event.loaded to the number of bytes available so far after gzip decoding
Implications of this are tested here as follows:
* If lengthComputable is true:
* must match Content-length header
* event.loaded must only ever increase in progress events
(and may never repeat its value).
* event.loaded must never exceed the Content-length.
* If lengthComputable is false:
* should be 0
* event.loaded must only ever increase in progress events
(and may never repeat its value).
* event.loaded should be the length of the decompressed content, i.e.
bigger than Content-length header value when finished loading
var lastTotal;
var lastLoaded = -1;
client.addEventListener('loadend', test.step_func(function(e){
var len = parseInt(client.getResponseHeader('content-length'), 10)
assert_equals(, len, ' is content-length')
assert_equals(e.loaded, len, 'event.loaded should be content-length at loadend')
assert_equals(, 0, 'if implementation can\'t compute for gzipped content it is 0')
assert_true(e.loaded >= len, 'event.loaded should be set even if total is not computable')
}), false)
client.addEventListener('progress', test.step_func(function(e){
if(lastTotal === undefined){
lastTotal =;
if(e.lengthComputable && && e.loaded){
assert_equals(, lastTotal, ' should remain invariant')
assert_less_than_equal(e.loaded, lastTotal, 'event.loaded should not exceed content-length')
assert_equals(, 0, ' should be 0')
assert_greater_than(e.loaded, lastLoaded, 'event.loaded should only ever increase')
lastLoaded = e.loaded;
}), false)
// image.gif is 165375 bytes compressed. Sending 45000 bytes at a time with 1 second delay will load it in 4 seconds"GET", "resources/image.gif?pipe=gzip|trickle(45000:d1:r2)", true)