Memory leak in IE11

I’m seeing memory leaks in IE11 after upgrading ember 2.18.2 to 3.1.2. Specifically between versions 3.0.0 and 3.1.0-beta.1.

On ember 3.1.0-beta.1, after ~350 acceptance tests, IE11 memory usage climbs to 2 GB then tests start failing with

Error: Out of memory
   at startRouting (assets/vendor.js:57541:11)
   at startRouting (assets/vendor.js:36654:7)
   at didBecomeReady (assets/vendor.js:37395:11)
   at invoke (assets/vendor.js:34638:17)
   at flush (assets/vendor.js:34558:25)
   at flush (assets/vendor.js:34711:21)
   at end (assets/vendor.js:34844:17)
   at _run (assets/vendor.js:35215:21)
   at run (assets/vendor.js:34902:13)
   at run (assets/vendor.js:51927:5)

On ember 3.0.0, all 450 acceptance tests run and IE11 memory usage is around 1 GB (which is high but not unusual for IE). For comparison, Chrome uses about 450 MB then drops to 200 MB after the tests finish.

My attempt to bisect seems to point to #15828 but there’s a big range of commits in there that I can’t build and/or run.

[dwickern]

I was testing on Windows 7 with IE 11.0.9600.18860

[rwjblue]

As I started digging into what the differences were in debug builds vs prod builds, I noticed that in prod we are not rendering anything (whereas in debug we render the {{welcome-page}} component). Removing that component invocation enables debug builds to pass without memory growth.

This made me attempt to add a very simple component with the same DOM as the welcome-page template which resulted in no memory growth (and all tests completed). The primary difference between this test run and the way the welcome-page addon is setup is that this tested with a normally resolved template whereas the addon imports its layout and reexports it.

After updating ember-welcome-page (locally) to make its template resolved (instead of imported and set as the layout property on the component’s JS file), I was able to re-run the test suite without any memory growth.