Tests for ValidateNotNull, ValidateNotNullOrEmpty are timing sensitive and unreliable. #5627

Tests in the ValidateAttributeTests.ps1 attempt to estimate the time it takes for these attributes to be applied and tests the various attributes to ensure they complete within the estimated time.

In CI, these tests can take 2-3 times longer than the estimate causing test failures.

See Context "ValidateNotNull, ValidateNotNullOrEmpty and Not-Null-Or-Empty check for Mandatory parameter" in the referenced file.

The following logic is used to calculate a baseline measurement:

Use the running time of 'MandatoryFunc -Value $byteArray' as the baseline time

$baseline = (Measure-Command { MandatoryFunc -Value $byteArray }).Milliseconds

Running time should be less than 'expected'

$expected = $baseline + 20