use Random in switch to avoid it from being optimized away (just guessing here)

Author: bert2

test/coverlet.core.tests/Coverage/CoverageTest.Yield.cs

@@ -19,7 +19,7 @@ public void Yield_Single()
                 {
                     CoveragePrepareResult coveragePrepareResult = await TestInstrumentationHelper.Run<Yield>(instance =>
                     {
-                        foreach(var _ in instance.One());
+                        foreach(var _ in instance.One()) ;
 
                         return Task.CompletedTask;
                     }, persistPrepareResultToFile: pathSerialize[0]);
@@ -50,7 +50,7 @@ public void Yield_Multiple()
                 {
                     CoveragePrepareResult coveragePrepareResult = await TestInstrumentationHelper.Run<Yield>(instance =>
                     {
-                        foreach (var _ in instance.Two());
+                        foreach (var _ in instance.Two()) ;
 
                         return Task.CompletedTask;
                     }, persistPrepareResultToFile: pathSerialize[0]);
@@ -80,7 +80,7 @@ public void Yield_SingleWithSwitch()
                 {
                     CoveragePrepareResult coveragePrepareResult = await TestInstrumentationHelper.Run<Yield>(instance =>
                     {
-                        foreach (var _ in instance.OneWithSwitch(2)) ;
+                        foreach (var _ in instance.OneWithSwitch()) ;
 
                         return Task.CompletedTask;
                     }, persistPrepareResultToFile: pathSerialize[0]);
@@ -92,7 +92,6 @@ public void Yield_SingleWithSwitch()
 
                 result.Document("Instrumentation.Yield.cs")
                       .Method("System.Boolean Coverlet.Core.Samples.Tests.Yield/<OneWithSwitch>d__2::MoveNext()")
-                      .AssertLinesCovered((30, 1), (31, 1), (37, 1))
                       .ExpectedTotalNumberOfBranches(1);
             }
             finally

test/coverlet.core.tests/Samples/Instrumentation.Yield.cs

@@ -15,10 +15,10 @@ public System.Collections.Generic.IEnumerable<int> Two()
             yield return 2;
         }
 
-        public System.Collections.Generic.IEnumerable<int> OneWithSwitch(int n)
+        public System.Collections.Generic.IEnumerable<int> OneWithSwitch()
         {
             int result;
-            switch (n)
+            switch (new System.Random().Next())
             {
                 case 0:
                     result = 10;