Added -CaseInsensitive switch parameter to Select-Object & Get-Unique cmdlets (#19683)

* Added Select-Object CaseInsensitive parameter and tests

* Added Get-Unique CaseInsensitive parameter and tests

* Fix codefactor issue

* Add named arguements

* Remove comments

test/powershell/Modules/Microsoft.PowerShell.Utility/Get-Unique.Tests.ps1

@@ -1,8 +1,12 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 Describe "Get-Unique DRT Unit Tests" -Tags "CI" {
-    It "Command get-unique works with AsString switch" {
+
+    BeforeAll {
         $inputArray = "aa","aa","Aa","ba","BA","BA"
+    }
+
+    It "Command get-unique works with AsString switch" {
         $results = $inputArray | Get-Unique -AsString
 
         $results.Length | Should -Be 4
@@ -17,6 +21,18 @@ Describe "Get-Unique DRT Unit Tests" -Tags "CI" {
         $results[2] | Should -BeOfType System.String
         $results[3] | Should -BeOfType System.String
     }
+
+    It "Command get-unique works with AsString and CaseInsensitive switches" {
+        $results = $inputArray | Get-Unique -AsString -CaseInsensitive
+
+        $results.Length | Should -Be 2
+
+        $results[0] | Should -BeExactly "aa"
+        $results[1] | Should -BeExactly "ba"
+
+        $results[0] | Should -BeOfType System.String
+        $results[1] | Should -BeOfType System.String
+    }
 }
 
 Describe "Get-Unique" -Tags "CI" {
@@ -26,6 +42,8 @@ Describe "Get-Unique" -Tags "CI" {
         $expectedOutput1 = 1,2,3,4,5
         $collection     = "a", "b", "b", "d"
         $expectedOutput2 = "a", "b", "d"
+        $collection2 = "a","A", "b", "B"
+        $expectedOutput3 = "a", "b"
     }
 
     It "Should be able to use the Get-Unique cmdlet without error with inputObject switch" {
@@ -61,4 +79,9 @@ Describe "Get-Unique" -Tags "CI" {
         $actual = $collection | Get-Unique
         $(Compare-Object $actual $expectedOutput2 -SyncWindow 0).Length | Should -Be 0
     }
+
+    It "Should get the unique strings when CaseInsensitive switch is used" {
+        $actual = $collection2 | Get-Unique -CaseInsensitive
+        $(Compare-Object $actual $expectedOutput3 -SyncWindow 0).Length | Should -Be 0
+    }
 }

test/powershell/Modules/Microsoft.PowerShell.Utility/Select-Object.Tests.ps1

@@ -58,6 +58,13 @@ Describe "Select-Object" -Tags "CI" {
         $result | Should -Be $expected
     }
 
+    It "Should work work correctly with Unique and CaseInsensitive parameter" {
+        $result = "abc", "Abc" | Select-Object -Unique -CaseInsensitive
+
+        $result.Count | Should -Be 1
+        $result | Should -Be "abc"
+    }
+
     It "Should return correct object with Skip parameter" {
         $result = $dirObject | Select-Object -Skip $TestLength