Add tests for command info cache keys to verify case-insensitivity and command-type filtering

Adding additional test cases from #2221.

Author: jessehouwing

Tests/Engine/CommandInfoCacheConcurrency.tests.ps1

@@ -114,3 +114,45 @@ public static class ConcurrentCommandLookup
             'Test-NonexistentCommandForRetryVerification', $null, $true) | Should -BeNullOrEmpty
     }
 }
+
+Describe "Command info cache keys" {
+    BeforeEach {
+        $cacheType = [Microsoft.Windows.PowerShell.ScriptAnalyzer.Helper].Assembly.GetType(
+            'Microsoft.Windows.PowerShell.ScriptAnalyzer.CommandInfoCache', $true)
+        $cache = [Activator]::CreateInstance($cacheType)
+    }
+
+    AfterEach {
+        $cache.Dispose()
+    }
+
+    It "returns the cached command for differently cased names and equivalent command types" {
+        $command = $cache.GetCommandInfo('Get-Item', $null, $false)
+        $command | Should -Not -BeNullOrEmpty
+        $cached = $cache.GetCommandInfo('gET-iTEM', [System.Management.Automation.CommandTypes]::All, $false)
+
+        [object]::ReferenceEquals($command, $cached) | Should -BeTrue
+    }
+
+    It "keeps command-type filters separate from an existing cache entry" {
+        $cache.GetCommandInfo('Get-Item', [System.Management.Automation.CommandTypes]::Function, $false) |
+            Should -BeNullOrEmpty
+        $command = $cache.GetCommandInfo('Get-Item', [System.Management.Automation.CommandTypes]::Cmdlet, $false)
+        $command.CommandType | Should -Be ([System.Management.Automation.CommandTypes]::Cmdlet)
+        $cache.GetCommandInfo('GET-ITEM', [System.Management.Automation.CommandTypes]::Function, $false) |
+            Should -BeNullOrEmpty
+    }
+
+    It "uses ordinal case-insensitive lookup independently of the current culture" {
+        $originalCulture = [System.Threading.Thread]::CurrentThread.CurrentCulture
+        try {
+            $command = $cache.GetCommandInfo('Get-Item', $null, $false)
+            [System.Threading.Thread]::CurrentThread.CurrentCulture = [System.Globalization.CultureInfo]::GetCultureInfo('tr-TR')
+            $cached = $cache.GetCommandInfo('get-item', $null, $false)
+
+            [object]::ReferenceEquals($command, $cached) | Should -BeTrue
+        } finally {
+            [System.Threading.Thread]::CurrentThread.CurrentCulture = $originalCulture
+        }
+    }
+}