[tests] Fix integer rounding error in GetTestFileName (#52266)

* [tests] Fix integer rounding error in GetTestFileName * Update src/libraries/Common/tests/TestUtilities/System/IO/FileCleanupTestBase.cs * Update src/libraries/Common/tests/TestUtilities/System/IO/FileCleanupTestBase.cs Co-authored-by: Mitchell Hwang <mitchell.hwang@microsoft.com> Co-authored-by: Dan Moseley <danmose@microsoft.com>
dotnet · May 5, 2021 · 69ac4c5 · 69ac4c5
1 parent c587b8d
commit 69ac4c5
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/src/libraries/Common/tests/TestUtilities/System/IO/FileCleanupTestBase.cs b/src/libraries/Common/tests/TestUtilities/System/IO/FileCleanupTestBase.cs
@@ -102,7 +102,9 @@ protected string GetTestFileName(int? index = null, [CallerMemberName] string me
                 if (excessLength < memberName.Length + "...".Length)
                 {
                     // Take a chunk out of the middle as perhaps it's the least interesting part of the name
-                    memberName = memberName.Substring(0, memberName.Length / 2 - excessLength / 2) + "..." + memberName.Substring(memberName.Length / 2 + excessLength / 2);
+                    int halfMemberNameLength = (int)Math.Floor((double)memberName.Length / 2);
+                    int halfExcessLength = (int)Math.Ceiling((double)excessLength / 2);
+                    memberName = memberName.Substring(0, halfMemberNameLength - halfExcessLength) + "..." + memberName.Substring(halfMemberNameLength + halfExcessLength);
 
                     testFileName = GenerateTestFileName(index, memberName, lineNumber);
                     testFilePath = Path.Combine(TestDirectory, testFileName);