HIGH-LOAD GUI TEST : panic: runtime error: invalid memory address or nil pointer dereference - frame.go

[LBouet]

During a high-load GUI test, opening a new tab may randomly cause this memory error.
This error causes the test to crash.

///////////////// ERROR START \\\\\\\\\\
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x38 pc=0x11f693a]

goroutine 10990869 [running]:
github.com/grafana/xk6-browser/common.(*Frame).requestByID(0xc212056fc0, {0xc1a600cf10, 0xa})
github.com/grafana/[email protected]/common/frame.go:412 +0x5a
github.com/grafana/xk6-browser/common.(*FrameManager).requestFailed(0xc1338a9500, 0xc1954437c0, 0x0)
github.com/grafana/[email protected]/common/frame_manager.go:454 +0x499
github.com/grafana/xk6-browser/common.(*NetworkManager).onLoadingFailed(0xc003f8ef00, 0xc0c29964e0)
github.com/grafana/[email protected]/common/network_manager.go:374 +0x111
github.com/grafana/xk6-browser/common.(*NetworkManager).handleEvents(0xc003f8ef00, 0xc2206f4480)
github.com/grafana/[email protected]/common/network_manager.go:347 +0x278
github.com/grafana/xk6-browser/common.(*NetworkManager).initEvents.func1()
github.com/grafana/[email protected]/common/network_manager.go:330 +0x31
created by github.com/grafana/xk6-browser/common.(*NetworkManager).initEvents in goroutine 10840679
github.com/grafana/[email protected]/common/network_manager.go:329 +0x13d
\\\\\\\\\\\ ERROR END //////////////////////////

It seems that in the initial code, if the frame session and the main frame session are null, null is not returned.
This fix allows you to return a null if the frames are null and no longer get the error.
To be tested by your teams before integrating it.

-> Function to be updated : FRAME.GO

func (f *Frame) requestByID(reqID network.RequestID) Request {
frameSession := f.page.getFrameSession(cdp.FrameID(f.ID()))
if frameSession == nil {
frameSession = f.page.mainFrameSession
}
/ ADD from "LoadTestingTeam" --- START /
if frameSession == nil {
return nil
} else {
return frameSession.networkManager.requestFromID(reqID)
}
/ ADD from LoadTestingTeam --- STOP */

/* DEL from LoadTestingTeam
return frameSession.networkManager.requestFromID(reqID)*/
}

[ankur22]

Hi @LBouet,

We recently tackled an issue (#1163) where we forced the caller to check that the second return value was true before trying to use the request (the first return value) from requestByID. This should make it into the next release. However, this change is unlikely to resolve the issue that you are facing.

On closer inspection it does feel prudent to check for nil before working with f.page.mainFrameSession. What we're not sure of at the moment is why f.page.mainFrameSession would be nil. What was the test setup like? Do you have a sample script that exhibits this error that we can try to run?

The original issue was filed under #986.