Bug 179488 – Fix preload/picture-type.html to address race conditions with preloader and necessary DPR test setup

• Component: Tools / Tests
• Status: RESOLVED DUPLICATE

[Colin Bendell]

Current test http/preload/picture-type.html can fail because of race conditions from the test setup. In order to test <source sizes srcset> tags, the browser DPR must be fixed. There is a pre-existing deficiency in testRunner.setBackingScaleFactor which requires the browser to reload for the target DPR to be effective in `srcset` evaluation. This unfortunately creates test delays and a race condition with the preloader and the page reload.

A less elegant solution is to adjust the `srcset` targets to account for a wide range of browser DPRs in the tests. This is adequate because this test is not testing the `srcset` evaluation logic but rather that `srcset` continues to work with the additional `type` attribute test.

[Colin Bendell]

Created attachment 326463 [details]
Patch

[Ryan Haddad]

Alex, any chance that you can review this change today?

[WebKit Commit Bot]

Comment on attachment 326463 [details]
Patch

Clearing flags on attachment: 326463

Committed r224697: <https://trac.webkit.org/changeset/224697>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Ryan Haddad]

The test is still a flaky failure after this change:
https://build.webkit.org/results/Apple%20Sierra%20Release%20WK2%20(Tests)/r224702%20(5659)/results.html

--- /Volumes/Data/slave/sierra-release-tests-wk2/build/layout-test-results/http/tests/preload/picture-type-expected.txt
+++ /Volumes/Data/slave/sierra-release-tests-wk2/build/layout-test-results/http/tests/preload/picture-type-actual.txt
@@ -1,40 +1,41 @@
-PASS internals.isPreloaded('resources/base-image1.png?0'); is true
+FAIL internals.isPreloaded('resources/base-image1.png?0'); should be true. Was false.
 PASS internals.isPreloaded('resources/preload-test.jpg?0'); is false
-PASS internals.isPreloaded('resources/base-image1.png?1'); is true
+FAIL internals.isPreloaded('resources/base-image1.png?1'); should be true. Was false.
 PASS internals.isPreloaded('resources/preload-test.jpg?1'); is false
-PASS internals.isPreloaded('resources/base-image1.png?2'); is true
+FAIL internals.isPreloaded('resources/base-image1.png?2'); should be true. Was false.
 PASS internals.isPreloaded('resources/preload-test.jpg?2'); is false
 PASS internals.isPreloaded('resources/base-image1.png?3'); is false
-PASS internals.isPreloaded('resources/preload-test.jpg?3'); is true
+FAIL internals.isPreloaded('resources/preload-test.jpg?3'); should be true. Was false.
 PASS internals.isPreloaded('resources/base-image1.png?4'); is false
 PASS internals.isPreloaded('resources/base-image2.png?4'); is false
-PASS internals.isPreloaded('resources/base-image3.png?4'); is true
+FAIL internals.isPreloaded('resources/base-image3.png?4'); should be true. Was false.
 PASS internals.isPreloaded('resources/preload-test.jpg?4'); is false
 PASS internals.isPreloaded('resources/base-image1.png?5'); is false
 PASS internals.isPreloaded('resources/base-image2.png?5'); is false
 PASS internals.isPreloaded('resources/base-image3.png?5'); is false
-PASS internals.isPreloaded('resources/preload-test.jpg?5'); is true
-PASS internals.isPreloaded('resources/base-image1.png?6'); is true
+FAIL internals.isPreloaded('resources/preload-test.jpg?5'); should be true. Was false.
+FAIL internals.isPreloaded('resources/base-image1.png?6'); should be true. Was false.
 PASS internals.isPreloaded('resources/preload-test.jpg?6'); is false
 PASS internals.isPreloaded('resources/base-image1.png?7'); is false
-PASS internals.isPreloaded('resources/preload-test.jpg?7'); is true
-PASS internals.isPreloaded('resources/base-image1.png?8'); is true
+FAIL internals.isPreloaded('resources/preload-test.jpg?7'); should be true. Was false.
+FAIL internals.isPreloaded('resources/base-image1.png?8'); should be true. Was false.
 PASS internals.isPreloaded('resources/preload-test.jpg?8'); is false
 PASS internals.isPreloaded('resources/base-image1.png?9'); is false
-PASS internals.isPreloaded('resources/preload-test.jpg?9'); is true
-PASS internals.isPreloaded('resources/base-image1.png?10'); is true
+FAIL internals.isPreloaded('resources/preload-test.jpg?9'); should be true. Was false.
+FAIL internals.isPreloaded('resources/base-image1.png?10'); should be true. Was false.
 PASS internals.isPreloaded('resources/base-image2.png?10'); is false
 PASS internals.isPreloaded('resources/preload-test.jpg?10'); is false
 PASS internals.isPreloaded('resources/base-image1.png?11'); is false
-PASS internals.isPreloaded('resources/base-image2.png?11'); is true
+FAIL internals.isPreloaded('resources/base-image2.png?11'); should be true. Was false.
 PASS internals.isPreloaded('resources/preload-test.jpg?11'); is false
-PASS internals.isPreloaded('resources/base-image1.png?12'); is true
+FAIL internals.isPreloaded('resources/base-image1.png?12'); should be true. Was false.
 PASS internals.isPreloaded('resources/base-image2.png?12'); is false
 PASS internals.isPreloaded('resources/preload-test.jpg?12'); is false
 PASS internals.isPreloaded('resources/base-image1.png?13'); is false
 PASS internals.isPreloaded('resources/base-image2.png?13'); is false
-PASS internals.isPreloaded('resources/preload-test.jpg?13'); is true
+FAIL internals.isPreloaded('resources/preload-test.jpg?13'); should be true. Was false.
 PASS successfullyParsed is true
+Some tests failed.
 
 TEST COMPLETE

[Ryan Haddad]

I'm going to roll it out again.

[WebKit Commit Bot]

Re-opened since this is blocked by bug 179545

[Ryan Haddad]

*** This bug has been marked as a duplicate of bug 179231 ***