Add tryWhich() function and enable manifests to have condition

Author: SteveL-MSFT

dsc/tests/dsc_extension_manifest.tests.ps1

@@ -0,0 +1,41 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+Describe 'Extension Manifests' {
+    It 'Extension manifests with condition: <condition>' -TestCases @(
+        @{ condition = "[equals(1, 1)]"; shouldBeFound = $true }
+        @{ condition = "[equals(1, 0)]"; shouldBeFound = $false }
+    ) {
+        param($condition, $shouldBeFound)
+
+        $extension_manifest = @"
+{
+    "`$schema": "https://aka.ms/dsc/schemas/v3/bundled/extension/manifest.json",
+    "type": "Test/Extension",
+    "condition": "$condition",
+    "version": "0.1.0",
+    "import": {
+        "fileExtensions": ["foo"],
+        "executable": "dsc"
+    }
+}
+"@
+
+        try {
+            $env:DSC_RESOURCE_PATH = $TestDrive
+            $manifestPath = Join-Path -Path $TestDrive -ChildPath 'Extension.dsc.extension.json'
+            $extension_manifest | Out-File -FilePath $manifestPath -Encoding utf8
+            $extensions = dsc extension list | ConvertFrom-Json -Depth 10
+            $LASTEXITCODE | Should -Be 0
+            if ($shouldBeFound) {
+                $extensions.count | Should -Be 1
+                $extensions.type | Should -BeExactly 'Test/Extension'
+            }
+            else {
+                $extensions.count | Should -Be 0
+            }
+        } finally {
+            $env:DSC_RESOURCE_PATH = $null
+        }
+    }
+}

dsc/tests/dsc_functions.tests.ps1

@@ -123,7 +123,7 @@ Describe 'tests for function expressions' {
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'))]"; expected = [pscustomobject]@{
         shared = [pscustomobject]@{ value = 42; flag = $true }
         level  = 1
-      } 
+      }
     }
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject3'))]"; expected = [pscustomobject]@{ level = 1 } }
     @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'), parameters('nestedObject4'))]"; expected = [pscustomobject]@{ level = 1 } }
@@ -948,10 +948,10 @@ Describe 'tests for function expressions' {
     @{ testInput = ' ' }
   ) {
     param($testInput)
-    
+
     $expected = [Uri]::EscapeDataString($testInput)
     $expression = "[uriComponent('$($testInput -replace "'", "''")')]"
-    
+
     $config_yaml = @"
             `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
             resources:
@@ -963,13 +963,13 @@ Describe 'tests for function expressions' {
     $out = $config_yaml | dsc config get -f - | ConvertFrom-Json
     $out.results[0].result.actualState.output | Should -BeExactly $expected
   }
-  
+
   It 'uriComponent function works with concat' {
     $input1 = 'hello'
     $input2 = ' '
     $input3 = 'world'
     $expected = [Uri]::EscapeDataString($input1 + $input2 + $input3)
-    
+
     $config_yaml = @"
             `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
             resources:
@@ -995,10 +995,10 @@ Describe 'tests for function expressions' {
     @{ testInput = '100%25' }
   ) {
     param($testInput)
-    
+
     $expected = [Uri]::UnescapeDataString($testInput)
     $expression = "[uriComponentToString('$($testInput -replace "'", "''")')]"
-    
+
     $config_yaml = @"
             `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
             resources:
@@ -1010,11 +1010,11 @@ Describe 'tests for function expressions' {
     $out = $config_yaml | dsc config get -f - | ConvertFrom-Json
     $out.results[0].result.actualState.output | Should -BeExactly $expected
   }
-  
+
   It 'uriComponentToString function works with round-trip encoding' {
     $original = 'hello world'
     $expected = $original
-    
+
     $config_yaml = @"
             `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
             resources:
@@ -1026,11 +1026,11 @@ Describe 'tests for function expressions' {
     $out = $config_yaml | dsc config get -f - | ConvertFrom-Json
     $out.results[0].result.actualState.output | Should -BeExactly $expected
   }
-  
+
   It 'uriComponentToString function works with nested round-trip' {
     $original = 'user+tag@example.com'
     $expected = $original
-    
+
     $config_yaml = @"
             `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
             resources:
@@ -1042,13 +1042,13 @@ Describe 'tests for function expressions' {
     $out = $config_yaml | dsc config get -f - | ConvertFrom-Json
     $out.results[0].result.actualState.output | Should -BeExactly $expected
   }
-  
+
   It 'uriComponentToString function works with concat' {
     $input1 = 'hello'
     $input2 = '%20'
     $input3 = 'world'
     $expected = [Uri]::UnescapeDataString($input1 + $input2 + $input3)
-    
+
     $config_yaml = @"
             `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
             resources:
@@ -1077,7 +1077,7 @@ Describe 'tests for function expressions' {
     @{ data = @{ nested = @{ value = 123 } }; accessor = '.nested.value'; expected = 123 }
   ) {
     param($data, $accessor, $expected)
-    
+
     $jsonString = ConvertTo-Json -Compress -InputObject $data
     $expression = "[json(''$($jsonString)'')$accessor]"
 
@@ -1116,4 +1116,27 @@ Describe 'tests for function expressions' {
     $errorContent = Get-Content $TestDrive/error.log -Raw
     $errorContent | Should -Match ([regex]::Escape('Invalid JSON string'))
   }
+
+  It 'tryWhich() works for: <expression>' -TestCases @(
+    @{ expression = "[tryWhich('pwsh')]"; found = $true }
+    @{ expression = "[tryWhich('nonexistentcommand12345')]"; found = $false }
+  ) {
+    param($expression, $found)
+
+    $config_yaml = @"
+            `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+            resources:
+            - name: Echo
+              type: Microsoft.DSC.Debug/Echo
+              properties:
+                output: "$expression"
+"@
+    $out = dsc -l trace config get -i $config_yaml 2>$TestDrive/error.log | ConvertFrom-Json
+    $LASTEXITCODE | Should -Be 0 -Because (Get-Content $TestDrive/error.log -Raw)
+    if ($found) {
+      $out.results[0].result.actualState.output | Should -Not -BeNullOrEmpty
+    } else {
+      $out.results[0].result.actualState.output | Should -BeNullOrEmpty
+    }
+  }
 }

dsc/tests/dsc_resource_manifest.tests.ps1

@@ -0,0 +1,51 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+Describe 'Resource Manifests' {
+    It 'Resource manifests with condition: <condition>' -TestCases @(
+        @{ condition = "[equals(1, 1)]"; shouldBeFound = $true }
+        @{ condition = "[equals(1, 0)]"; shouldBeFound = $false }
+    ) {
+        param($condition, $shouldBeFound)
+
+        $resource_manifest = @"
+{
+    "`$schema": "https://aka.ms/dsc/schemas/v3/bundled/resource/manifest.json",
+    "type": "Test/MyEcho",
+    "version": "1.0.0",
+    "condition": "$condition",
+    "get": {
+        "executable": "dscecho",
+        "args": [
+            {
+                "jsonInputArg": "--input",
+                "mandatory": true
+            }
+        ]
+    },
+    "schema": {
+        "command": {
+            "executable": "dscecho"
+        }
+    }
+}
+"@
+
+        try {
+            $env:DSC_RESOURCE_PATH = $TestDrive
+            $manifestPath = Join-Path -Path $TestDrive -ChildPath 'MyEcho.dsc.resource.json'
+            $resource_manifest | Out-File -FilePath $manifestPath -Encoding utf8
+            $resources = dsc resource list | ConvertFrom-Json -Depth 10
+            $LASTEXITCODE | Should -Be 0
+            if ($shouldBeFound) {
+                $resources.count | Should -Be 1
+                $resources.type | Should -BeExactly 'Test/MyEcho'
+            }
+            else {
+                $resources.count | Should -Be 0
+            }
+        } finally {
+            $env:DSC_RESOURCE_PATH = $null
+        }
+    }
+}

extensions/bicep/bicep.dsc.extension.json

@@ -3,6 +3,7 @@
     "type": "Microsoft.DSC.Extension/Bicep",
     "version": "0.1.0",
     "description": "Enable passing Bicep file directly to DSC, but requires bicep executable to be available.",
+    "condition": "[not(equals(tryWhich('bicep'), null()))]",
     "import": {
         "fileExtensions": ["bicep"],
         "executable": "bicep",

lib/dsc-lib/locales/en-us.toml

@@ -110,6 +110,8 @@ foundResourceWithVersion = "Found matching resource '%{resource}' version %{vers
 foundNonAdapterResources = "Found %{count} non-adapter resources"
 resourceMissingRequireAdapter = "Resource '%{resource}' is missing 'require_adapter' field."
 extensionDiscoverFailed = "Extension '%{extension}' failed to discover resources: %{error}"
+conditionNotBoolean = "Condition '%{condition}' did not evaluate to a boolean"
+conditionNotMet = "Condition '%{condition}' not met, skipping manifest at '%{path}'"
 
 [dscresources.commandResource]
 invokeGet = "Invoking get for '%{resource}'"
@@ -533,6 +535,10 @@ invoked = "tryGet function"
 invalidKeyType = "Invalid key type, must be a string"
 invalidIndexType = "Invalid index type, must be an integer"
 
+[functions.tryWhich]
+description = "Attempts to locate an executable in the system PATH.  Null is returned if the executable is not found otherwise the full path to the executable is returned."
+invoked = "tryWhich function"
+
 [functions.union]
 description = "Returns a single array or object with all elements from the parameters"
 invoked = "union function"