Expanding tests.

src/EditorFeatures/CSharpTest/UseConditionalExpression/UseConditionalExpressionForReturnTests.cs

@@ -584,6 +584,38 @@ int M()
 }");
         }
 
+        [WorkItem(27960, "https://github.com/dotnet/roslyn/issues/27960")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUseConditionalExpression)]
+        public async Task TestOnYieldReturn_IEnumerableReturnType()
+        {
+            await TestInRegularAndScriptAsync(
+@"
+using System.Collections.Generic;
+
+class C
+{
+    IEnumerable<int> M()
+    {
+        [||]if (true)
+        {
+            yield return 0;
+        }
+        else
+        {
+            yield return 1;
+        }
+    }
+}",
+@"
+class C
+{
+    int M()
+    {
+        yield return true ? 0 : 1;
+    }
+}");
+        }
+
         [WorkItem(27960, "https://github.com/dotnet/roslyn/issues/27960")]
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUseConditionalExpression)]
         public async Task TestNotOnMixedYields()
@@ -606,6 +638,30 @@ int M()
 }");
         }
 
+        [WorkItem(27960, "https://github.com/dotnet/roslyn/issues/27960")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUseConditionalExpression)]
+        public async Task TestNotOnMixedYields_IEnumerableReturnType()
+        {
+            await TestMissingAsync(
+@"
+using System.Collections.Generic;
+
+class C
+{
+    IEnumerable<int> M()
+    {
+        [||]if (true)
+        {
+            yield break;
+        }
+        else
+        {
+            yield return 1;
+        }
+    }
+}");
+        }
+
         [WorkItem(27960, "https://github.com/dotnet/roslyn/issues/27960")]
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUseConditionalExpression)]
         public async Task TestNotWithNoElseBlockButFollowingYieldReturn()
@@ -625,5 +681,27 @@ void M()
     }
 }");
         }
+
+        [WorkItem(27960, "https://github.com/dotnet/roslyn/issues/27960")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUseConditionalExpression)]
+        public async Task TestNotWithNoElseBlockButFollowingYieldReturn_IEnumerableReturnType()
+        {
+            await TestMissingAsync(
+@"
+using System.Collections.Generic;
+
+class C
+{
+    IEnumerable<int> M()
+    {
+        [||]if (true)
+        {
+            yield return 0;
+        }
+
+        yield return 1;
+    }
+}");
+        }
     }
 }