🐛 (TfsTestPlansAndSuitesMigrationProcessor.cs): handle duplicate test plan names

Enhance the `FindTestPlan` method to handle scenarios where multiple
test plans have the same name. Previously, the code assumed that test
plan names were unique, which could lead to unexpected behavior or
errors if duplicates existed. The updated logic checks for multiple
test plans with the same name, logs a warning with their IDs, and
throws an exception to prevent further execution. This ensures that
the migration process does not proceed with ambiguous test plan
identification, maintaining data integrity.

Author: MrHinsh

src/MigrationTools.Clients.TfsObjectModel/Processors/TfsTestPlansAndSuitesMigrationProcessor.cs

@@ -607,8 +607,16 @@ private ITestSuiteBase FindSuiteEntry(IStaticTestSuite staticSuite, string title
         private ITestPlan FindTestPlan(string planName, int sourcePlanId)
         {
             Log.LogDebug("TestPlansAndSuitesMigrationContext::FindTestPlan");
-            ITestPlan testPlan = (from p in _targetTestStore.Project.TestPlans.Query("Select * From TestPlan") where p.Name == planName select p).SingleOrDefault();
- 
+            ITestPlan testPlan;
+            List<ITestPlan> testPlans = (from p in _targetTestStore.Project.TestPlans.Query("Select * From TestPlan") where p.Name == planName select p).ToList();
+            if (testPlans.Count > 1)
+            {
+                string result = string.Join(",", testPlans.Select(obj => obj.Id));
+                Log.LogWarning("We found multiple test Plans with the name '{TestPlanName}'. They have ID(s) of '{result}'! We only have name at this point as a unique identifier and duplicates will break the code. Ensure that all Test Plans have unique names.", planName, result);
+                throw new Exception(string.Format("Test plans {0} all have the same name!", result));
+            }
+            testPlan = testPlans[0];
+
             if (testPlan != null)
             {
                 Log.LogDebug("TestPlansAndSuitesMigrationContext::FindTestPlan:: FOUND Test Plan with {name}", planName);
@@ -1173,4 +1181,4 @@ private void ValidateAndFixTestSuiteQuery(ITestSuiteBase source, IDynamicTestSui
             }
         }
     }
-}
+}