add comments

Author: tgauth

dsc_lib/src/configure/config_doc.rs

@@ -30,6 +30,7 @@ pub enum Operation {
 #[derive(Debug, Clone, PartialEq, Deserialize, Serialize, JsonSchema)]
 pub enum ExecutionKind {
     Actual,
+    // differentiate internally whether what-if should be processed by the resource or dsc engine
     #[serde(rename = "WhatIf")]
     WhatIfDSC,
     #[serde(rename = "WhatIf")]

dsc_lib/src/dscresources/command_resource.rs

@@ -131,7 +131,7 @@ pub fn invoke_set(resource: &ResourceManifest, cwd: &str, desired: &str, skip_te
     }
 
     if ExecutionKind::WhatIfDSC == *execution_type {
-        return Err(DscError::NotImplemented("cannot process what-if execution type, resource does not implement what-if or pre-test".to_string()));
+        return Err(DscError::NotImplemented("cannot process what-if execution type, as resource implements pre-test and does not support what-if".to_string()));
     }
 
     let Some(get) = &resource.get else {
@@ -639,7 +639,7 @@ fn process_args(args: &Option<Vec<ArgKind>>, value: &str, execution_type: &Execu
                 processed_args.push(json_input_arg.clone());
                 processed_args.push(value.to_string());
             },
-            ArgKind::WhatIf { what_if_input_arg} => {
+            ArgKind::WhatIf { what_if_input_arg } => {
                 if execution_type == &ExecutionKind::WhatIfResource {
                     processed_args.push(what_if_input_arg.clone());
                 }

dsc_lib/src/dscresources/resource_manifest.rs

@@ -176,9 +176,6 @@ pub struct SetMethod {
     /// Indicates that the resource directly handles `_exist` as a property.
     #[serde(rename = "handlesExist", skip_serializing_if = "Option::is_none")]
     pub handles_exist: Option<bool>,
-    /// Indicates that the resource directly handles `what-if` execution type.
-    #[serde(rename = "handlesWhatIf", skip_serializing_if = "Option::is_none")]
-    pub handles_what_if: Option<bool>,
     /// The type of return value expected from the Set method.
     #[serde(rename = "return", skip_serializing_if = "Option::is_none")]
     pub returns: Option<ReturnKind>,

tools/dsctest/dscwhatif.dsc.resource.json

@@ -16,7 +16,6 @@
                 "whatIfInputArg": "--what-if"
             }
         ],
-        "implementsPretest": true,
         "return": "state"
     },
     "schema": {