Powershell Test-Path in foreach loop null - powershell

Question

I have a list of numbers in a file (123-45-678, 876-54-321, but they're on separate lines) and I'm trying to do something if a number is in the file and something else if it is not.
$list = Get-Content $env:USERPROFILE\Documents\list.txt
Foreach ($obj in $list)
{
$nxt = Get-ChildItem -Path $env:USERPROFILE\Documents\files -Recurse -Filter "*$obj*"
$FileExists = Test-Path $nxt
If ($FileExists -ne $True)
{
Write-Host "Yippee"
}
Else
{
Write-Host "Not found"
}
}
If there is a number in the file it seems to work but if it's not I get the following
TEST-PATH : Cannot bind argument to parameter 'Path' because it is null.
I thought the purpose of test-path was to return something if it couldn't find anything?

Answer 1

Why are you negating the results of both Test-Path and if([System.IO.File]::Exists($nxt)) ?
If either returns $true, then the file EXISTS.
Because you say you want to do something if a file with any such number in its name is found and something else if not, I would do it using the regular expression -match operator.
For that, you need to put all possible numbers from the text file in a single string, separated by the regex OR operator |:
# get the numbers from the file and for security remove empty or whitespace-only lines
$list = Get-Content -Path "$env:USERPROFILE\Documents\list.txt" | Where-Object { $_ -match '\S' }
# build a regex string from that array
$regex = ($list | ForEach-Object { [regex]::Escape($_) }) -join '|'
# get all files and test if they match any of the numbers
Get-ChildItem -Path "$env:USERPROFILE\Documents\files" -Recurse -File | ForEach-Object {
if ( $_.Name -match $regex ) {
Write-Host "File '$($_.Name)' exists" -ForegroundColor Green
}
else {
Write-Host "File '$($_.FullName)' does not match any of the items in the list."
}
}
Result would look something like this:
File '876-54-321.txt' exists
File 'C:\snowman\Documents\files\somefile.txt' does not match any of the items in the list.
File 'Whatever 123-45-678-901.txt' exists
File 'XYZ 876-54-321.txt' exists