Compare-Object only reports differences by default, requiring explicit opt-in for inclusion of equal objects via -IncludeEqual.

Therefore, the only meaningful behavior when you use -ExcludeDifferent is to default to -IncludeEqual.

Without that, as is currently the case, nothing is ever output, so it is currently effectively pointless to pass -ExcludeDifferent without also passing -IncludeEqual.

Steps to reproduce

Compare-Object 1,2 3, 1 -ExcludeDifferent -PassThru -IncludeEqual  | Should -Be 1
# Currently produces NO output, because -IncludeEqual isn't implied.
Compare-Object 1,2 3, 1 -ExcludeDifferent -PassThru | Should -Be 1

Expected behavior

Both tests should pass.

Actual behavior

The 2nd test fails, because -IncludeEqual is not implied.

Environment data

PowerShell Core 7.0.0-rc.2