7Zip - Powershell - $LastExitCode Issues - powershell

Question

Pretty sure just me not knowing what to do but I am having issues with a 7zip PS script and the $LastExitCode
ForEach ($File in $Files) {
7zip a “$DestDir\$file.7z” "$SourceDir\$File” -m0=LZMA2 -mx=9 -mmt4 | findstr /I "archive everything error" | Out-File $LOGPath -Force -Append
7zip t "$DestDir\$file.7z" | findstr /I "testing size compressed archive everything error" | Out-File $LOGPath -Force -Append
if ($LASTEXITCODE -eq 0) {
Write-Output “Compression SUCCEEDED and zip file tested OK” | Out-File $LOGPath -Force -Append
Write-Output “DELETING ORIGINAL file - $File `n” | Out-File $LOGPath -Force -Append
Remove-Item -Path “$SourceDir\$File” | Out-File $LOGPath -Force -Append
}
else {
Write-Output “Compression FAILED, source file not deleted `n” | Out-File $LOGPath -Force -Append
}
}
This is the script (important bits)
It does a zip then a test of the created package
So to test that the $LastExitCode is working (or not), I # out the zip part and leave the test step and remove any zip files from the destination folder. The zip test step fails as expected and sends an error to log (Error:cannot find archive) but still goes through with the remove-item, which should only occur if the test passes I would have throught??
Not sure what I am doing worng here? Or if this is the incorrect way to go about this?
I want to create the archive, confirm it is OK, then delete the original source file if it is (i.e. no errors).
Any advice really apprecited
thanks
EDIT
Ended up with below that seems to do the trick - thanks for the advice
ForEach ($File in $Files) {
Write-Output “Compressing $File” | Out-File $LOGPath -Force -Append
7zip a "$DestDir\$file.7z” "$SourceDir\$File" -m0=LZMA2 -mx=9 -mmt4
if ($LASTEXITCODE -eq 0) {
Write-Output "Compression SUCCEEDED" | Out-File $LOGPath -Force -Append
Write-Output “TESTING compressed file - $File” | Out-File $LOGPath -Force -Append
7zip t "$DestDir\$file.7z"
if ($LASTEXITCODE -eq 0) {
Write-Output "Zip file tested OK" | Out-File $LOGPath -Force -Append
Write-Output "DELETING original file - $File `n" | Out-File $LOGPath -Force -Append
#Remove-Item -Path “$SourceDir\$File” | Out-File $LOGPath -Force -Append
}
else {
Write-Output “Zip test FAILED, source file not deleted `n” | Out-File $LOGPath -Force -Append
}
}
else {
Write-Output "Compression FAILED for file - $file - moving onto next file" | Out-File $LOGPath -Force -Append
}
}