Powershell: Writing errors and ouput to a text file and Console

Question

I am trying to write the entire output (errors included) of an executing script to the console and a file at the same time. I have tried several different options

.\MyScript.ps1 | tee -filePath C:\results.txt # only the output to the file
.\MyScript.ps1 2> C:\results.txt # only the errors to the file and not the console
.\MyScript.ps1 > C:\results.txt # only the output to the file and not the console 

My hope was that I could use the file to review the output/errors

Any help would be greatly appreciated.

EDIT:

This is my current test script. The desired results is that all three messages can be seen.

function Test-Error 
{
    echo "echo"
    Write-Warning "warning"
    Write-Error "error"       
}

Test-Error 2>&1 | tee -filePath c:\results.txt

Answer 1

Have you tried

 .\MyScript.ps1 2>&1 | tee -filePath c:\results.txt

2>&1 should be what you're looking for.