fix: preserve missing domain controller build data

I now report absent build values as collection failures instead of valid empty or zero data, with regression coverage for both registry values.

Signed-off-by: Adil Alperen Çiftci <adilalperenciftci@users.noreply.github.com>

Author: adilalperenciftci

src/CommonLib/Processors/DCRegistryProcessor.cs

@@ -39,18 +39,20 @@ public StrRegistryAPIResult GetCurrentBuildNumber(string target)
             const string subValue = "CurrentBuildNumber";
             var data = _registryAccessor.GetRegistryKeyData(target, subKey, subValue);
 
-            ret.Collected = data.Collected;
             if (!data.Collected)
             {
                 ret.FailureReason = data.FailureReason;
                 return ret;
             }
 
-            if (data.Value != null)
+            if (data.Value == null)
             {
-                ret.Value = (string)data.Value;
+                ret.FailureReason = "Registry value was not found";
+                return ret;
             }
 
+            ret.Collected = true;
+            ret.Value = (string)data.Value;
             return ret;
         }
 
@@ -66,18 +68,20 @@ public IntRegistryAPIResult GetCurrentBuildRevision(string target)
             const string subValue = "UBR";
             var data = _registryAccessor.GetRegistryKeyData(target, subKey, subValue);
 
-            ret.Collected = data.Collected;
             if (!data.Collected)
             {
                 ret.FailureReason = data.FailureReason;
                 return ret;
             }
 
-            if (data.Value != null)
+            if (data.Value == null)
             {
-                ret.Value = (int)data.Value;
+                ret.FailureReason = "Registry value was not found";
+                return ret;
             }
 
+            ret.Collected = true;
+            ret.Value = (int)data.Value;
             return ret;
         }
 

test/unit/DCRegistryProcessorTests.cs

@@ -59,5 +59,36 @@ public void GetCurrentBuildRevision_PreservesCollectionFailure() {
             Assert.False(result.Collected);
             Assert.Equal("access denied", result.FailureReason);
         }
+
+        [Fact]
+        public void GetCurrentBuildNumber_ReportsMissingValue() {
+            _registryAccessor
+                .Setup(s => s.GetRegistryKeyData(Target, CurrentVersionKey, "CurrentBuildNumber"))
+                .Returns(new RegistryResult {
+                    Collected = true,
+                    Value = null
+                });
+
+            var result = _processor.GetCurrentBuildNumber(Target);
+
+            Assert.False(result.Collected);
+            Assert.Null(result.Value);
+            Assert.Equal("Registry value was not found", result.FailureReason);
+        }
+
+        [Fact]
+        public void GetCurrentBuildRevision_ReportsMissingValue() {
+            _registryAccessor
+                .Setup(s => s.GetRegistryKeyData(Target, CurrentVersionKey, "UBR"))
+                .Returns(new RegistryResult {
+                    Collected = true,
+                    Value = null
+                });
+
+            var result = _processor.GetCurrentBuildRevision(Target);
+
+            Assert.False(result.Collected);
+            Assert.Equal("Registry value was not found", result.FailureReason);
+        }
     }
 }