Calling ToString directly avoids any magic PowerShell might apply when converting a value to string.

You could just call LanguagePrimitives.ConvertTo<string>(setValue) - this will properly call into a CodeMethod or ScriptMethod named ToString if the object has one.

Done.

You should also test that we properly invoke ToString implemented as a CodeMethod and ScriptMethod. System.Type has a CodeMethod implementation of ToString, you can see the difference:

#57 PS> [System.Int32].ToString()
System.Int32
#58 PS> [string][System.Int32]
int

Done.
Only I could not create ToString ScriptMethod because ToString already exists.

I think this condition is unreachable now.

We can convert everything to string (including $null which turns into the empty string).

The only failure condition now is if the conversion to string fails with an exception, e.g. if ToString() throws an exception. This should be rare, but if it happens, I think we'd want to see that exception and not the SetValueException that is being thrown here.

In other words, I think this test and subsequent throw can be safely deleted.

Fixed.

I would add tests for:

• $null
• array of strings
• array of integers
• psobject wrapping each of the previous values

Fixed.
But I have doubts about [PSObject]::AsPSObject($null) and [PSObject]::AsPSObject(1)

We don't always call ToString.

PS> $x = 1,2
PS> [System.Management.Automation.LanguagePrimitives]::ConvertTo($x, [string])
1 2
PS> $x.ToString()
System.Object[]

Fixed.