[Test Improver] Add unit tests for TimeSpanParser

[Evangelink]

Fixes #7852

[Copilot]

Pull request overview

Adds a new unit test suite for Microsoft.Testing.Platform.Helpers.TimeSpanParser, which is used by Microsoft.Testing.Platform to parse human-friendly timeout/duration strings.

Changes:

• Introduces TimeSpanParserTests covering TryParse and Parse for common suffixes (ms/s/m/h/d) and invalid inputs.
• Adds coverage for whitespace inputs, “no suffix” inputs (milliseconds), and some decimal/whitespace-before-suffix scenarios.

Show a summary per file

File	Description
test/UnitTests/Microsoft.Testing.Platform.UnitTests/Helpers/TimeSpanParserTests.cs	New MSTest-based unit tests for TimeSpanParser parsing behaviors

Copilot's findings

Comments suppressed due to low confidence (1)

test/UnitTests/Microsoft.Testing.Platform.UnitTests/Helpers/TimeSpanParserTests.cs:165

• TryParse_SpaceBetweenValueAndSuffix_ParsesCorrectly doesn't validate the parsed value/unit, and expectedMs is unused (also misleading for inputs like "5 m" which should be minutes). Consider asserting the expected TimeSpan for each case (or renaming the parameter) so the test verifies behavior rather than only non-zero output.

    [TestMethod]
    [DataRow("5 s", 5)]
    [DataRow("5 ms", 5)]
    [DataRow("5 m", 5)]
    public void TryParse_SpaceBetweenValueAndSuffix_ParsesCorrectly(string input, double expectedMs)
    {
        // The regex allows optional whitespace before suffix
        bool result = TimeSpanParser.TryParse(input, out TimeSpan value);
        Assert.IsTrue(result);
        Assert.AreNotEqual(TimeSpan.Zero, value);
    }

• Files reviewed: 1/1 changed files
• Comments generated: 4