Fix registry resource to handle deleting non-existing reg value/key

registry/src/registry_helper.rs

@@ -200,7 +200,12 @@ impl RegistryHelper {
             Err(e) => return Err(e),
         };
         if let Some(value_name) = &self.config.value_name {
-            reg_key.delete_value(value_name)?;
+            match reg_key.delete_value(value_name) {
+                Ok(()) | Err(value::Error::NotFound(_, _)) => {
+                    // if the value doesn't exist, we don't need to do anything
+                },
+                Err(e) => return Err(RegistryError::RegistryValue(e)),
+            }
         } else {
             // to delete the key, we need to open the parent key first
             let parent_path = get_parent_key_path(&self.config.key_path);
@@ -215,7 +220,12 @@ impl RegistryHelper {
                 return Err(RegistryError::Utf16Conversion("subkey_name".to_string()));
             };
 
-            parent_reg_key.delete(subkey_name, true)?;
+            match parent_reg_key.delete(subkey_name, true) {
+                Ok(()) | Err(key::Error::NotFound(_, _)) => {
+                    // if the subkey doesn't exist, we don't need to do anything
+                },
+                Err(e) => return Err(RegistryError::RegistryKey(e)),
+            }
         }
         Ok(())
     }

registry/tests/registry.config.set.tests.ps1

@@ -99,4 +99,50 @@ Describe 'registry config set tests' {
 
         Remove-Item -Path 'HKCU:\1' -Recurse -ErrorAction Ignore
     }
+
+    It 'Should succeed when _exist is false and value does not exist' -Skip:(!$IsWindows) {
+        $config = @{
+            '$schema' = 'https://aka.ms/dsc/schemas/v3/bundled/config/document.json'
+            resources = @(
+                @{
+                    name = 'reg'
+                    type = 'Microsoft.Windows/Registry'
+                    properties = @{
+                        keyPath = 'HKCU'
+                        valueName = 'Test'
+                        valueData = @{
+                            String = 'Test'
+                        }
+                        _exist = $false
+                    }
+                }
+            )
+        }
+
+        $out = dsc config set -i ($config | ConvertTo-Json -Depth 10) | ConvertFrom-Json
+        $LASTEXITCODE | Should -Be 0
+        $out.results[0].result.afterState._exist | Should -Be $false
+
+        Get-ItemProperty -Path 'HKCU:\1\2' -Name 'Test' -ErrorAction Ignore | Should -BeNullOrEmpty
+    }
+
+    It 'Should succeed when _exist is false and key does not exist' -Skip:(!$IsWindows) {
+        $config = @{
+            '$schema' = 'https://aka.ms/dsc/schemas/v3/bundled/config/document.json'
+            resources = @(
+                @{
+                    name = 'reg'
+                    type = 'Microsoft.Windows/Registry'
+                    properties = @{
+                        keyPath = 'HKCU\1'
+                        _exist = $false
+                    }
+                }
+            )
+        }
+
+        $out = dsc config set -i ($config | ConvertTo-Json -Depth 10) | ConvertFrom-Json
+        $LASTEXITCODE | Should -Be 0
+        $out.results[0].result.afterState._exist | Should -Be $false
+    }
 }