fix build script and handle input to scripts

Author: SteveL-MSFT

build.ps1

@@ -430,7 +430,8 @@ if (!$SkipBuild) {
                 Copy-Item "*.dsc.resource.json" $target -Force -ErrorAction Ignore
             }
             else { # don't copy WindowsPowerShell resource manifest
-                Copy-Item "*.dsc.resource.json" $target -Exclude 'windowspowershell.dsc.resource.json' -Force -ErrorAction Ignore
+                $exclude = @('windowspowershell.dsc.resource.json', 'winpsscript.dsc.resource.json')
+                Copy-Item "*.dsc.resource.json" $target -Exclude $exclude -Force -ErrorAction Ignore
             }
 
             # be sure that the files that should be executable are executable

resources/PSScript/psscript.dsc.resource.json

@@ -51,7 +51,8 @@
     "exitCodes": {
         "0": "Success",
         "1": "PowerShell script execution failed",
-        "2": "PowerShell exception occurred"
+        "2": "PowerShell exception occurred",
+        "3": "Script had errors"
     },
     "schema": {
         "embedded": {

resources/PSScript/psscript.ps1

@@ -9,7 +9,7 @@ param(
     [string]$jsonInput
 )
 
-$traceQueue = [System.Collections.Queue]::new()
+$traceQueue = [System.Collections.Concurrent.ConcurrentQueue[object]]::new()
 
 function Write-DscTrace {
     param(
@@ -57,57 +57,90 @@ if ($null -eq $script) {
     exit 0
 }
 
+# use AST to see if script has param block, if any errors exit with error message
+$errors = $null
+$tokens = $null
+$ast = [System.Management.Automation.Language.Parser]::ParseInput($script, [ref]$tokens, [ref]$errors)
+if ($errors.Count -gt 0) {
+    $errorMessage = $errors | ForEach-Object { $_.ToString() }
+    Write-DscTrace -Now -Level Error -Message "Script has syntax errors: $errorMessage"
+    exit 3
+}
+
+$paramName = if ($ast.ParamBlock -ne $null) {
+    # make sure it only specifies one parameter and get the name of that parameter
+    if ($ast.ParamBlock.Parameters.Count -ne 1) {
+        Write-DscTrace -Now -Level Error -Message 'Script must have exactly one parameter.'
+        exit 3
+    }
+    $ast.ParamBlock.Parameters[0].Name.VariablePath.UserPath
+} else {
+    $null
+}
+
 $ps = [PowerShell]::Create().AddScript({
     $DebugPreference = 'Continue'
     $VerbosePreference = 'Continue'
     $ErrorActionPreference = 'Stop'
-})
+}).AddScript($script)
 
 if ($null -ne $scriptObject.input) {
-    $null = $ps.AddScript({
-        $global:inputArg = $scriptObject.input
-    })
+    if ($null -eq $paramName) {
+        Write-DscTrace -Now -Level Error -Message 'Input was provided but script does not have a parameter to accept input.'
+        exit 3
+    }
+    $null = $ps.AddParameter($paramName, $scriptObject.input)
+} elseif ($null -ne $paramName) {
+    Write-DscTrace -Now -Level Error -Message "Script has a parameter '$paramName' but no input was provided."
+    exit 3
 }
 
-$null = $ps.AddScript($script)
-
 $ps.Streams.Error.add_DataAdded({
     param($sender, $args)
-    Write-DscTrace -Level Error -Message $sender.Message
+    Write-DscTrace -Level Error -Message ($sender.Message | Out-String)
 })
 $ps.Streams.Warning.add_DataAdded({
     param($sender, $args)
-    Write-DscTrace -Level Warn -Message $sender.Message
+    Write-DscTrace -Level Warn -Message ($sender.Message | Out-String)
 })
 $ps.Streams.Information.add_DataAdded({
     param($sender, $args)
-    Write-DscTrace -Level Trace -Message $sender.MessageData.ToString()
+    Write-DscTrace -Level Trace -Message ($sender.MessageData | Out-String)
 })
 $ps.Streams.Verbose.add_DataAdded({
     param($sender, $args)
-    Write-DscTrace -Level Info -Message $sender.Message
+    Write-DscTrace -Level Info -Message ($sender.Message | Out-String)
 })
 $ps.Streams.Debug.add_DataAdded({
     param($sender, $args)
-    Write-DscTrace -Level Debug -Message $sender.Message
+    Write-DscTrace -Level Debug -Message ($sender.Message | Out-String)
 })
 $outputObjects = [System.Collections.Generic.List[Object]]::new()
 
+function write-traces() {
+    $trace = $null
+    while (!$traceQueue.IsEmpty) {
+        if ($traceQueue.TryDequeue([ref] $trace)) {
+            $host.ui.WriteErrorLine($trace)
+        }
+    }
+}
+
 try {
     $asyncResult = $ps.BeginInvoke()
     while (-not $asyncResult.IsCompleted) {
-        While ($traceQueue.Count -gt 0) {
-            $trace = $traceQueue.Dequeue()
-            $host.ui.WriteErrorLine($trace)
-        }
+        write-traces
+        Start-Sleep -Milliseconds 100
     }
     $outputCollection = $ps.EndInvoke($asyncResult)
+    write-traces
+
     foreach ($output in $outputCollection) {
         $outputObjects.Add($output)
     }
 }
 catch {
-    Write-DscTrace -Now -Level Error -Message $_.Exception.Message
+    Write-DscTrace -Now -Level Error -Message ($_.Exception | Out-String)
     exit 1
 }
 finally {
@@ -120,11 +153,6 @@ if ($ps.HadErrors) {
     exit 1
 }
 
-While ($traceQueue.Count -gt 0) {
-    $trace = $traceQueue.Dequeue()
-    $host.ui.WriteErrorLine($trace)
-}
-
 # Test should return a single boolean value indicating if in the desired state
 if ($Operation -eq 'Test') {
     if ($outputObjects.Count -eq 1 -and $outputObjects[0] -is [bool]) {

resources/PSScript/psscript.tests.ps1

@@ -270,7 +270,8 @@ Describe 'Tests for PSScript resource' {
 
         $yaml = @'
         getScript: |
-          "Input: $input"
+          param($inputObj)
+          "Input: $inputObj"
         input: "This is a string"
 '@
         $result = dsc resource get -r $resourceType -i $yaml 2> $TestDrive/error.txt | ConvertFrom-Json
@@ -279,4 +280,29 @@ Describe 'Tests for PSScript resource' {
         $result.actualState.output[0] | Should -BeExactly "Input: This is a string"
     }
 
+    It 'Input without param block is an error for <resourecType>' -TestCases $testCases {
+        param($resourceType)
+
+        $yaml = @'
+        getScript: |
+          "This should fail"
+        input: "This is a string"
+'@
+        dsc resource get -r $resourceType -i $yaml 2> $TestDrive/error.txt | ConvertFrom-Json
+        $LASTEXITCODE | Should -Be 2 -Because (Get-Content $TestDrive/error.txt -Raw | Out-String)
+        (Get-Content $TestDrive/error.txt -Raw) | Should -BeLike '*ERROR*:*Input was provided but script does not have a parameter to accept input.*'
+    }
+
+    It 'Param without input is an error for <resourceType>' -TestCases $testCases {
+        param($resourceType)
+
+        $yaml = @'
+        getScript: |
+          param($inputObj)
+          "This should fail"
+'@
+        dsc resource get -r $resourceType -i $yaml 2> $TestDrive/error.txt | ConvertFrom-Json
+        $LASTEXITCODE | Should -Be 2 -Because (Get-Content $TestDrive/error.txt -Raw | Out-String)
+        (Get-Content $TestDrive/error.txt -Raw) | Should -BeLike "*ERROR*:*Script has a parameter 'inputObj' but no input was provided.*"
+    }
 }