PowerShell Load XML with XML Schema - Whitespace replace

Question

I am trying to read in an xml document that is defined by an xml schema with a whiteSpace replace restriction on one of the elements, but when I try to access that element with PowerShell, all the whitespace is still there.

From my research, a whiteSpace replace restriction should tell the xml reader to replace all the newlines and tabs with a single space (w3schools)

For replication I have:

test.xml

<DOC xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="test.xsd">
    <Description>
        Here I have a long description
        that takes multiple lines, but I'd
        like it formatted nicely in this document -
        even though it should be all one line when
        parsed.
    </Description>
</DOC>

test.xsd

<?xml version="1.0" encoding="UTF-8" ?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="DOC">
    <xs:complexType>
        <xs:all>
            <xs:element name="Description" minOccurs="0">
                <xs:simpleType>
                    <xs:restriction base="xs:string">
                        <xs:whiteSpace value="replace" />
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
        </xs:all>
    </xs:complexType>
</xs:element>

</xs:schema>

And then in PowerShell v5.0 I try the following commands:

$document = New-Object System.Xml.XmlDocument

$readersettings = New-Object -TypeName System.Xml.XmlReaderSettings
$readersettings.ValidationType = [System.Xml.ValidationType]::Schema
$readersettings.ValidationFlags = [System.Xml.Schema.XmlSchemaValidationFlags]::ProcessInlineSchema -bor [System.Xml.Schema.XmlSchemaValidationFlags]::ProcessSchemaLocation
$docPath = (Get-Item 'test.xml').FullName
$reader = [System.Xml.XmlReader]::Create($docPath, $private:readersettings)
$document.Load($private:reader)
$reader.Close()

Write-Output $document.DOC.Description

Which writes out the following:

      Here I have a long description
      that takes multiple lines, but I'd
      like it formatted nicely in this document -
      even though it should be all one line when
      parsed.

What I want is for this to return

Here I have a long description that takes multiple lines, but I'd like it formatted nicely in this document - even though it should be all one line when parsed.

I also tried:

• setting the xml reader's IgnoreWhitespace Property to true.
• setting xs:whiteSpace value="collapse"
• making Description of type xs:normalizedString
• making Description of type xs:token

How can I tell the .NET xml reader that this element should have its whitespaces replaced with a single space?

Update

Despite MSDN's support of the types xs:token and xs:normalizedString in their System.Xml.Schema.XmlTypeCode enumeration, it does not appear that .NET actually conforms to the standard by replacing/collapsing the white space characters

This is not very satisfactory, but since I know which element I want collapsed, I can use PowerShell's -replace operator to collapse the whitespace for me and then use string trim to clean up any extra white space on the edges

PS C:\>($document.DOC.Description -replace '(\s)+',' ').Trim()

Is there any other way to do this during the $document.Load() to effectively extend the .NET class so my whitespace is collapsed on load of the xml and not just when I access it and purposefully replace it?