Trying to compare web service response and expected xml from file - web-services

Question

We're developing in Java for the most, but we want to integration test (using https://github.com/scottmuc/Pester) our web-services with ms as well. To do this I'm writing powershell scripts that connects to a web-service and compares the response to xml that I've loaded from a file.
[System.Net.ServicePointManager]::ServerCertificateValidationCallback = {$true}
$instance = New-WebServiceProxy -Uri "https://localhost:7002/service?WSDL" -Namespace "myspace"
$instance.Credentials = new-object System.Net.NetworkCredential("user", "pass")
...
$reply = $instance.fetchInformation($inputA, $inputB)
[xml]$expected = Get-Content ("expected.xml")
...
However, now I have a $reply that contains objects from the myspace namespace and an $expected that contains an XMLNode. I see two ways I can do this (there are probably many more):
Get the original XML response and compare that. However, I can't seem to find out how to get that.
Serialise the $expected XML into the myspace namespace objects. Is that possible?

Answer 1

You could serialize the response returned by the web service to XML and compare it with the contents of the expected.xml file as strings.
Here's an example:
$writer = New-Object System.IO.StringWriter
$serializer = New-Object System.Xml.Serialization.XmlSerializer($reply.GetType())
$serializer.Serialize($writer, $reply)
$replyAsXml = $writer.ToString()
$expectedReplyAsXml = Get-Content expected.xml
$replyAsXml -eq $expectedReplyAsXml
Note that in this example you need to make sure that XML contained in the expected.xml file matches the one returned by the XmlSerializer also in regard to spacing and indenting. In order to avoid that, you could strip all extra characters (such as spaces and newlines) from the two strings before comparing them.

Answer 2

I ended up with a completely different approach. The two XML's was quite different from each other so instead I created a custom comparator. This made it possible for me to simply write custom code to ignore uninteresting differences.
This lead to some pile of crude code that does the job:
# Assume two arrays of equal length
Function Zip {
Param($a1, $a2)
$sum = New-Object object[] $a1.Count
For ($i = 0; $i -lt $a1.Count; ++$i) {
$sum[$i] = New-Object object[] 2
$sum[$i][0] = $a1[$i]
$sum[$i][1] = $a2[$i]
}
Return ,$sum
}
Function XmlChildNodes2List{
param($nodes)
$myArray = New-Object object[] 0
For ($i = 0; $i -lt $nodes.Count; ++$i) {
$node = $nodes.Item($i)
If ($node -ne $null) {
$myArray += $node
}
}
Return ,$myArray
}
Function ShowContext{
Param($ctx)
" at " + $ctx
}
Function CompareNode{
Param($o1, $o2, $ctx)
Try {
Switch ($o1.GetType().Name) {
"XmlDocument" {
CompareXml $o1.ChildNodes $o2.ChildNodes
}
"XmlChildNodes" {
$olist1 = XmlChildNodes2List $o1 | Sort
$olist2 = XmlChildNodes2List $o2 | Sort
If ($olist1.Count -ne $olist2.Count) {
$msg = "Unequal child node count " + ($olist1 -join ",") + " and " + ($olist2 -join ",") + (ShowContext $ctx)
throw $msg
} Else {
$list = Zip $olist1 $olist2
$value = $true
foreach ($item in $list) {
if ($value -eq $true) {
$value = CompareXml $item[0] $item[1] $ctx
}
}
$value
}
}
"XmlElement" {
If ($o1.LocalName -eq $o2.LocalName) {
If ($o1.LocalName -eq "uninterestingElement" -or $o1.LocalName -eq "uninterestingElement2") {
$true
} Else {
CompareXML $o1.ChildNodes $o2.ChildNodes ($ctx + "/" + $o1.LocalName)
}
} Else {
throw ("Element " + $o1.LocalName + " != " + $o2.LocalName + (ShowContext $ctx))
}
}
"XmlDeclaration" {
$true
}
"XmlText" {
$result = $o1.InnerText.Replace("`r`n","`n")
$expect = $o2.InnerText.Replace("`r`n","`n")
# TODO: Hack to remove timezone from expected dates in format 2005-09-01+02:00, the webservice side of the
# reply to xml-conversion looses them
If ($expect -match "^(\d{4}-\d\d-\d\d)\+\d\d:\d\d$") {
$expect = $Matches[1]
}
If ($result -eq $expect) {
$true
} Else {
throw ($o1.InnerText + " is not equal to " + $o2.InnerText + (ShowContext $ctx))
}
}
Default {
throw ("What to do with node " + $o1.GetType().Name + (ShowContext $ctx))
}
}
} Catch [Exception] {
throw $_
}
}
Function CompareXML{
Param($o1, $o2, $ctx)
If ($o1 -eq $null -and $o2 -eq $null) {
$true
} ElseIf ($o1 -eq $null -or $o2 -eq $null) {
throw ("Response or expected is null")
} ElseIf ($o1.GetType() -eq $o2.GetType()) {
CompareNode $o1 $o2 $ctx
} Else {
throw ($o1.GetType().Name + " is not " + $o2.GetType().Name + (ShowContext $ctx))
}
}
This can then be run on two XML's like this:
CompareXML $result $expected ""