One of the challenges of writing error handling is determining whether the error is terminating or non-terminating.

A possible solution is to force all errors to be terminating by setting ErrorActionPreference to Stop.

Setting ErrorActionPreference to Stop is equivalent to adding -ErrorAction Stop to every command that supports it.

When exploring nesting try-catch-finally, the following example was used:

try {    
    Connect-Server 
    Get-ManagementObject | ForEach-Object { 
        try {     
            $_ | Set-ManagementObject -Property 'NewValue' 
        } catch { 
            Write-Error -ErrorRecord $_ 
        } finally { 
            $_ 
        }    
    }     
} catch { 
    throw
} 

Setting ErrorActionPreference to Stop would remove the need to set an ErrorAction parameter on each of the commands (if those commands wrote non-terminating errors). However, doing so would also cause any informational errors written by Write-Error to completely stop the script.

For a script that implements a process, where the error handling can be strictly defined, the following workaround might be used. ErrorAction for Write-Error is forcefully set to Continue, overriding the value held in the preference variable:

$ErrorActionPreference = 'Stop' 
try {    
    Connect-Server 
    Get-ManagementObject | ForEach-Object { 
        try {     
            $_ | Set-ManagementObject -Property 'NewValue' 
        } catch { 
            Write-Error -ErrorRecord $_ -ErrorAction Continue 
        } finally { 
            $_ 
        }    
    }     
} catch { 
    throw
} 

Setting ErrorActionPreference to Stop is harder to apply when writing tools, such as when writing the commands used by this script; doing so would remove the choice from the end user.

A need for complex error handling is often a sign that a script should be broken down into smaller units.