Don't crash on CIM classes with no superclass

Rules/UseIdenticalMandatoryParametersDSC.cs

@@ -258,7 +258,7 @@ private IDictionary<string, string> GetKeys(string fileName)
 
             var cimClass = cimClasses?.FirstOrDefault();
             var cimSuperClassProperties = new HashSet<string>(
-                cimClass?.CimSuperClass.CimClassProperties.Select(p => p.Name) ??
+                cimClass?.CimSuperClass?.CimClassProperties.Select(cimPropertyDeclaration => cimPropertyDeclaration.Name) ??
                 Enumerable.Empty<string>());
 
             return cimClass?

Tests/Rules/DSCResourceModule/DSCResources/ClassWithNoParent/ClassWithNoParent.psm1

@@ -0,0 +1,2 @@
+#requires -Version 4.0 -Modules CimCmdlets
+

Tests/Rules/DSCResourceModule/DSCResources/ClassWithNoParent/ClassWithNoParent.schema.mof

@@ -0,0 +1,6 @@
+[ClassVersion("1.0.0")]
+class ClassWithNoParent
+{
+    [Write] Boolean Anonymous;
+};
+

Tests/Rules/UseIdenticalMandatoryParametersForDSC.tests.ps1

@@ -7,6 +7,7 @@ $badResourceFilepath = [System.IO.Path]::Combine(
     'MSFT_WaitForAnyNoIdenticalMandatoryParameter.psm1');
 $goodResourceFilepath = [System.IO.Path]::Combine($resourceBasepath,'MSFT_WaitForAny','MSFT_WaitForAny.psm1');
 
+$noparentClassFilepath = [System.IO.Path]::Combine($resourceBasepath,'ClassWithNoParent','ClassWithNoParent.psm1');
 
 Describe "UseIdenticalMandatoryParametersForDSC" {
     Context "When a mandatory parameters are not present" {
@@ -33,4 +34,12 @@ Describe "UseIdenticalMandatoryParametersForDSC" {
             $violations.Count | Should -Be 0
         }
     }
+
+    Context "When a CIM class has no parent" {
+        # regression test for #982 - just check no uncaught exception
+        It "Should find no violations, and throw no exceptions" {
+            $violations = Invoke-ScriptAnalyzer -Path $noParentClassFilepath -IncludeRule $ruleName
+            $violations.Count | Should -Be 0
+        }
+    }
 }