Bug 212696 – REGRESSION: (r262432): [ iOS wk2 ] imported/w3c/web-platform-tests/service-workers/service-worker/fetch-request-no-freshness-headers.https.html is flaky failing.

• Status: RESOLVED
• Resolution: CONFIGURATION CHANGED
• Component: Tools / Tests

[Jason Lawrence]

imported/w3c/web-platform-tests/service-workers/service-worker/fetch-request-no-freshness-headers.https.html

Description:
This test is flaky failing on iOS wk2. The test was passing consistently until 06/2/2020.

History:
https://results.webkit.org/?suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fservice-workers%2Fservice-worker%2Ffetch-request-no-freshness-headers.https.html&platform=ios&limit=50000

Diff: 
--- /Volumes/Data/worker/iOS-13-Simulator-WK2-Tests-EWS/build/layout-test-results/imported/w3c/web-platform-tests/service-workers/service-worker/fetch-request-no-freshness-headers.https-expected.txt
+++ /Volumes/Data/worker/iOS-13-Simulator-WK2-Tests-EWS/build/layout-test-results/imported/w3c/web-platform-tests/service-workers/service-worker/fetch-request-no-freshness-headers.https-actual.txt
@@ -1,3 +1,3 @@
 
-FAIL The headers of FetchEvent shouldn't contain freshness headers. assert_false: if-none-match header must not be set in the FetchEvent's request. (url = https://localhost:9443/service-workers/service-worker/resources/fetch-request-no-freshness-headers-script.py) expected false got true
+PASS The headers of FetchEvent shouldn't contain freshness headers.

[Radar WebKit Bug Importer]

<rdar://problem/63928394>

[Jason Lawrence]

I can reproduce this issue with r262432, but I cannot reproduce it with r262431.
Command:
run-webkit-tests --ios-simulator --iterations 99 --exit-after-n-failures 3 imported/w3c/web-platform-tests/service-workers/service-worker/fetch-request-no-freshness-headers.https.html

r262432 results:
[1/99] imported/w3c/web-platform-tests/service-workers/service-worker/fetch-request-no-freshness-headers.https.html failed unexpectedly (text diff)
[2/99] imported/w3c/web-platform-tests/service-workers/service-worker/fetch-request-no-freshness-headers.https.html failed unexpectedly (text diff)
[3/99] imported/w3c/web-platform-tests/service-workers/service-worker/fetch-request-no-freshness-headers.https.html failed unexpectedly (text diff)
Exiting early after 3 failures. 3 tests run.
0 tests ran as expected, 3 didn't (96 didn't run):


r262431 results:
All 99 tests ran as expected.

[Jason Lawrence]

I have marked this test as flaky failing while this issue is investigated. 
https://trac.webkit.org/changeset/262489/webkit

[youenn fablet]

https://trac.webkit.org/changeset/262489/webkit is most probably ensuring that the service worker is run in the same process as the page, thus potentially reusing the memory cache. It seems strange though that this is iOS sim only.

[youenn fablet]

Or maybe this is due to timing, and the reuse of the existing process makes the test run a bit faster.
I do not think we are breaking behavior.

[Jason Lawrence]

I have removed the expectations because the test no longer appears to be failing: https://trac.webkit.org/changeset/263507/webkit