[perf-improver] perf: fast path in HumanReadableDurationFormatter.Render for sub-hour durations

src/Platform/Microsoft.Testing.Platform/OutputDevice/Terminal/HumanReadableDurationFormatter.cs

@@ -62,6 +62,23 @@ public static string Render(TimeSpan? duration, bool wrapInParentheses = true, b
             return string.Empty;
         }
 
+#if NET8_0_OR_GREATER
+        // Fast path for the common non-negative progress-frame case: duration < 1 hour with no milliseconds.
+        if (!showMilliseconds && duration.Value.Ticks >= 0 && duration.Value.Days == 0 && duration.Value.Hours == 0)
+        {
+            int seconds = duration.Value.Seconds;
+            int minutes = duration.Value.Minutes;
+
+            return (wrapInParentheses, minutes) switch
+            {
+                (true, 0) => $"({seconds}s)",
+                (true, _) => $"({minutes}m {seconds:D2}s)",
+                (false, 0) => $"{seconds}s",
+                _ => $"{minutes}m {seconds:D2}s",
+            };
+        }
+#endif
+
         bool hasParentValue = false;
 
         var stringBuilder = new StringBuilder();

test/UnitTests/Microsoft.Testing.Platform.UnitTests/OutputDevice/Terminal/HumanReadableDurationFormatterTests.cs

@@ -0,0 +1,35 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using Microsoft.Testing.Platform.OutputDevice.Terminal;
+
+namespace Microsoft.Testing.Platform.UnitTests;
+
+[TestClass]
+public sealed class HumanReadableDurationFormatterTests
+{
+    [TestMethod]
+    public void Render_WhenDurationIsNull_ReturnsEmptyString()
+        => Assert.AreEqual(string.Empty, HumanReadableDurationFormatter.Render(null));
+
+    [TestMethod]
+    [DataRow(0, true, "(0s)")]
+    [DataRow(5, true, "(5s)")]
+    [DataRow(65, true, "(1m 05s)")]
+    [DataRow(3599, true, "(59m 59s)")]
+    [DataRow(65, false, "1m 05s")]
+    public void Render_WhenSubHourDurationDoesNotShowMilliseconds_FormatsDuration(int totalSeconds, bool wrapInParentheses, string expected)
+        => Assert.AreEqual(expected, HumanReadableDurationFormatter.Render(TimeSpan.FromSeconds(totalSeconds), wrapInParentheses));
+
+    [TestMethod]
+    public void Render_WhenSubHourDurationShowsMilliseconds_FormatsDurationWithMilliseconds()
+        => Assert.AreEqual("(1m 05s 123ms)", HumanReadableDurationFormatter.Render(TimeSpan.FromMilliseconds(65_123), showMilliseconds: true));
+
+    [TestMethod]
+    public void Render_WhenSubHourDurationIsNegative_PreservesExistingFormatting()
+        => Assert.AreEqual("(0s)", HumanReadableDurationFormatter.Render(TimeSpan.FromMinutes(-1)));
+
+    [TestMethod]
+    public void Render_WhenDurationHasHours_FormatsDurationWithHours()
+        => Assert.AreEqual("(1h 02m 03s)", HumanReadableDurationFormatter.Render(new TimeSpan(0, 1, 2, 3)));
+}