Array buffer allocation failed during ember test

I recently updated ember-qunit to latest which also required me to install qunit and @ember/test-helpers manually. I noticed that when I would run my ~7000 unit tests that I would run into an error like this:

not ok 1889 Chrome 92.0 - [1221 ms] - Unit | Component | <myComponent>
    ---
        actual: >
            null
        stack: >
            RangeError: Array buffer allocation failed
                at new ArrayBuffer (<anonymous>)
                at new Int32Array (<anonymous>)
                at new HeapImpl (http://localhost:9001/assets/vendor.js:70039:19)
                at artifacts (http://localhost:9001/assets/vendor.js:70301:13)
                at new Renderer (http://localhost:9001/assets/vendor.js:35061:52)
                at new InteractiveRenderer (http://localhost:9001/assets/vendor.js:35316:3)
                at Function.create (http://localhost:9001/assets/vendor.js:35325:14)
                at FactoryManager.create (http://localhost:9001/assets/vendor.js:25093:25)
                at Proxy.create (http://localhost:9001/assets/vendor.js:24811:20)
                at instantiateFactory (http://localhost:9001/assets/vendor.js:24912:71)

To be honest, not sure where to go from here. Any advice would be appreciated.

ember-cli: 3.24.0
node: 14.17.3
nom: 6.14.13

Note: I opened an issue on the ember-cli repo as well -- not sure best place to put this.

[rwjblue]

What version of Ember are you using?

What version of Ember are you using?

3.24.4

[rwjblue]

That error looks like glimmer-vm is attempting to create its heap (which it does via a typed array), and that is throwing an error. For context, here is the implementation of HeapImpl:

https://github.com/glimmerjs/glimmer-vm/blob/4f1bef0d9a8a3c3ebd934c5b6e09de4c5f6e4468/packages/%40glimmer/program/lib/program.ts#L77

[rwjblue]

When does this error happen? Is it the first test, or somewhere in the middle of your 7k test suite? What is the memory consumed at the time the error happens?

It occurs usually after around ~1500 tests have completed.

How should I calculate the memory in order to show you?

Something else worth noting, if I use ember-exam and use --split 4 --parallel, they pass just fine.

[rwjblue]

How should I calculate the memory in order to show you?

I was thinking just using Chrome's Window -> Task Manager functionality to see what the tab is using.

Sure! It's also worth noting this error occurs either in the browser (via /tests) or in the command line (via ember test).

By the time the errors start to show up, I'm seeing ~900MB memory usage in the tab and it failed around test 1800.

Some more data:

We have 7385 tests, ~1000 integration tests, 10 application, and the rest unit.

[tkraak]

Turns out that the entire test suite runs just fine on Firefox.

But I can confirm @justinzelinsky numbers. In latest Chrome it crashes right after 1800 tests have run at a memory allocation of ~900MB.

[rwjblue]

Is the memory growing and eventually crashes at ~ 900, or is it fairly steady?

[rwjblue]

The thing I'm trying to figure out here is if this error is happening due to a memory leak throughout the test suite...

[tkraak]

The memory is definitely growing and eventually crashes at ~900MB.

Would a memory leak somewhere in the test suite also explain why Firefox has no issue running the entire suite?

[tkraak]

Firefox memory consumption maxes out at 50MB somewhere during the first 1000 tests (mostly application and rendering tests) and then drops just below 10MB for the rest of the suite (unit tests).

[rwjblue]

Would a memory leak somewhere in the test suite also explain why Firefox has no issue running the entire suite?

Not sure to be honest. It doesn't obviously rule it out though (it's totally possible that FireFox will support more overall memory used by a tab before preventing it). What is the memory used by FireFox? Does it also continue to grow (even past the ~900MB level)?

[rwjblue]

Haha, you beat me to the question!