Implement schema option for PsDscAdapter

.vscode/settings.json

@@ -12,6 +12,7 @@
         "./y2j/Cargo.toml"
     ],
     "rust-analyzer.showUnlinkedFileNotification": true,
+    "powershell.codeFormatting.preset": "OTBS",
     "json.schemas": [
         {
             "fileMatch": ["**/*.dsc.resource.json"],

powershell-adapter/Tests/TestClassResource/testclassresource.dsc.resource.json

@@ -0,0 +1,22 @@
+{
+    "$schema": "https://raw.githubusercontent.com/PowerShell/DSC/main/schemas/2024/04/bundled/resource/manifest.json",
+    "type": "TestClassResource/TestClassResource",
+    "description": "Manage test class",
+    "tags": [
+        "Windows"
+    ],
+    "version": "0.1.0",
+    "schema": {
+    "command": {
+      "executable": "pwsh",
+      "args": [
+        "-NoLogo",
+        "-NonInteractive",
+        "-NoProfile",
+        "-Command",
+        "$Input | ./psDscAdapter/powershell.resource.ps1 Schema"
+      ],
+      "input": "stdin"
+    }
+  }
+}

powershell-adapter/Tests/powershellgroup.resource.tests.ps1

@@ -345,4 +345,24 @@ Describe 'PowerShell adapter resource tests' {
         $res = $r | ConvertFrom-Json
         $res.actualState.HashTableProp.Name | Should -Be 'DSCv3'
     }
+
+    It "Verify that schema operation works on PS class-based resource" {
+        BeforeDiscovery {
+            $resourceManifest = Resolve-Path -Path (Join-Path $PSScriptRoot 'TestClassResource' 'testclassresource.dsc.resource.json')
+            $dest = Split-Path -Path ((Get-Command dsc).Source) -Parent
+            $script:file = Copy-Item -Path $resourceManifest -Destination $dest -Force -PassThru
+        }
+
+        # Rebuild the cache file first
+        dsc resource list --adapter Microsoft.DSC/PowerShell | Out-Null
+
+        $r = dsc resource schema --resource TestClassResource/TestClassResource
+        $properties = $r | ConvertFrom-Json
+        $properties.required | Should -Not -BeNullOrEmpty
+        $properties.properties.PSObject.properties.Name.Contains('BaseProperty') | Should -BeTrue
+    }
 }
+
+AfterAll {
+    Remove-Item -Path $file.FullName -Force -ErrorAction SilentlyContinue
+}

powershell-adapter/psDscAdapter/powershell.resource.ps1

@@ -2,8 +2,8 @@
 # Licensed under the MIT License.
 [CmdletBinding()]
 param(
-    [Parameter(Mandatory = $true, Position = 0, HelpMessage = 'Operation to perform. Choose from List, Get, Set, Test, Export, Validate, ClearCache.')]
-    [ValidateSet('List', 'Get', 'Set', 'Test', 'Export', 'Validate', 'ClearCache')]
+    [Parameter(Mandatory = $true, Position = 0, HelpMessage = 'Operation to perform. Choose from List, Get, Set, Test, Export, Validate, Schema, ClearCache.')]
+    [ValidateSet('List', 'Get', 'Set', 'Test', 'Export', 'Validate', 'Schema', 'ClearCache')]
     [string]$Operation,
     [Parameter(Mandatory = $false, Position = 1, ValueFromPipeline = $true, HelpMessage = 'Configuration or resource input in JSON format.')]
     [string]$jsonInput = '@{}'
@@ -27,19 +27,19 @@ function Write-DscTrace {
 'PSPath=' + $PSHome | Write-DscTrace
 'PSModulePath=' + $env:PSModulePath | Write-DscTrace
 
-if ($Operation -eq 'ClearCache') {
-    $cacheFilePath = if ($IsWindows) {
-        # PS 6+ on Windows
-        Join-Path $env:LocalAppData "dsc\PSAdapterCache.json"
+$cacheFilePath = if ($IsWindows) {
+    # PS 6+ on Windows
+    Join-Path $env:LocalAppData "dsc\PSAdapterCache.json"
+} else {
+    # either WinPS or PS 6+ on Linux/Mac
+    if ($PSVersionTable.PSVersion.Major -le 5) {
+        Join-Path $env:LocalAppData "dsc\WindowsPSAdapterCache.json"
     } else {
-        # either WinPS or PS 6+ on Linux/Mac
-        if ($PSVersionTable.PSVersion.Major -le 5) {
-            Join-Path $env:LocalAppData "dsc\WindowsPSAdapterCache.json"
-        } else {
-            Join-Path $env:HOME ".dsc" "PSAdapterCache.json"
-        }
+        Join-Path $env:HOME ".dsc" "PSAdapterCache.json"
     }
+}
 
+if ($Operation -eq 'ClearCache') {
     'Deleting cache file ' + $cacheFilePath | Write-DscTrace
     Remove-Item -Force -ea SilentlyContinue -Path $cacheFilePath
     exit 0
@@ -56,8 +56,7 @@ if ('Validate' -ne $Operation) {
     # load private functions of psDscAdapter stub module
     if ($PSVersionTable.PSVersion.Major -le 5) {
         $psDscAdapter = Import-Module "$PSScriptRoot/win_psDscAdapter.psd1" -Force -PassThru
-    }
-    else {
+    } else {
         $psDscAdapter = Import-Module "$PSScriptRoot/psDscAdapter.psd1" -Force -PassThru
     }
 
@@ -70,8 +69,7 @@ if ($jsonInput) {
         $inputobj_pscustomobj = $jsonInput | ConvertFrom-Json
     }
     $new_psmodulepath = $inputobj_pscustomobj.psmodulepath
-    if ($new_psmodulepath)
-    {
+    if ($new_psmodulepath) {
         $env:PSModulePath = $ExecutionContext.InvokeCommand.ExpandString($new_psmodulepath)
     }
 }
@@ -83,7 +81,7 @@ switch ($Operation) {
 
         # cache was refreshed on script load
         foreach ($dscResource in $dscResourceCache) {
-        
+
             # https://learn.microsoft.com/dotnet/api/system.management.automation.dscresourceinfo
             $DscResourceInfo = $dscResource.DscResourceInfo
 
@@ -102,20 +100,17 @@ switch ($Operation) {
             # this text comes directly from the resource manifest for v3 native resources
             if ($DscResourceInfo.Description) {
                 $description = $DscResourceInfo.Description
-            }
-            elseif ($module.Description) {
+            } elseif ($module.Description) {
                 # some modules have long multi-line descriptions. to avoid issue, use only the first line.
                 $description = $module.Description.split("`r`n")[0]
-            }
-            else {
+            } else {
                 $description = ''
             }
 
             # match adapter to version of powershell
             if ($PSVersionTable.PSVersion.Major -le 5) {
                 $requireAdapter = 'Microsoft.Windows/WindowsPowerShell'
-            }
-            else {
+            } else {
                 $requireAdapter = 'Microsoft.DSC/PowerShell'
             }
 
@@ -135,7 +130,7 @@ switch ($Operation) {
             } | ConvertTo-Json -Compress
         }
     }
-    { @('Get','Set','Test','Export') -contains $_ } {
+    { @('Get', 'Set', 'Test', 'Export') -contains $_ } {
         $desiredState = $psDscAdapter.invoke(   { param($jsonInput) Get-DscResourceObject -jsonInput $jsonInput }, $jsonInput )
         if ($null -eq $desiredState) {
             Write-DscTrace -Operation Error -message 'Failed to create configuration object from provided input JSON.'
@@ -176,7 +171,7 @@ switch ($Operation) {
             }
             $result += $actualState
         }
-    
+
         # OUTPUT json to stderr for debug, and to stdout
         if ($Operation -eq 'Test') {
             $result = @{ result = $result; _inDesiredState = $inDesiredState } | ConvertTo-Json -Depth 10 -Compress
@@ -187,14 +182,47 @@ switch ($Operation) {
         Write-DscTrace -Operation Debug -Message "jsonOutput=$result"
         return $result
     }
+    'Schema' {
+        $cache = Get-Content $cacheFilePath | ConvertFrom-Json
+
+        # TODO: Validate how input is passed and remove hindden properties
+        $resourceInfoproperties = ($cache.ResourceCache | Where-Object { $_.Type -eq 'TestClassResource/TestClassResource' }).DscResourceInfo.Properties
+
+        $props = @{}
+        $resourceInfoproperties | Foreach-Object {
+            if ($_.IsMandatory -eq $true) {
+                $props[$_.Name] = [hashtable]@{
+                    type        = $_.PropertyType
+                    description = ""
+                }
+            } else {
+                $props[$_.Name] = [hashtable]@{
+                    type        = @($_.PropertyType, $null)
+                    description = ""
+                }
+            }
+        }
+
+        $out = [resourceProperties]@{
+            schema               = 'http://json-schema.org/draft-12/schema#'
+            title                = ($cache.ResourceCache | Where-Object { $_.Type -eq 'TestClassResource/TestClassResource' }).Type
+            type                 = 'object'
+            required             = @($resourceInfoproperties | Where-Object { $_.IsMandatory -eq $true }).Name
+            properties           = $props
+            additionalProperties = $false
+            # definitions = $null # TODO: Should we add definitions
+        }
+
+        $out | ConvertTo-Json -Depth 10 -Compress
+    }
     'Validate' {
         # VALIDATE not implemented
-        
+
         # OUTPUT
         @{ valid = $true } | ConvertTo-Json
     }
     Default {
-        Write-DscTrace -Operation Error -Message 'Unsupported operation. Please use one of the following: List, Get, Set, Test, Export, Validate'
+        Write-DscTrace -Operation Error -Message 'Unsupported operation. Please use one of the following: List, Get, Set, Test, Export, Schema, and Validate'
     }
 }
 
@@ -212,3 +240,12 @@ class resourceOutput {
     [string] $requireAdapter
     [string] $description
 }
+
+class resourceProperties {
+    [string] $schema
+    [string] $title
+    [string] $type
+    [string[]] $required
+    [hashtable] $properties
+    [bool] $additionalProperties
+}