add tests for get-command -ShowCommandInfo (PowerShell#4906)

Author: chunqingchen

test/powershell/Modules/Microsoft.PowerShell.Core/Pester.Commands.Cmdlets.GetCommand.Tests.ps1

@@ -14,6 +14,7 @@ Describe "Tests Get-Command with relative paths and wildcards" -Tag "CI" {
             /bin/chmod 777 "$file1"
             /bin/chmod 777 "$file2"
         }
+        $commandInfo = Get-Command Get-Date -ShowCommandInfo
     }
 
     It "Test wildcard with drive relative directory path" {
@@ -49,4 +50,52 @@ Describe "Tests Get-Command with relative paths and wildcards" -Tag "CI" {
         Pop-Location
     }
 
+    It "Get-Command -ShowCommandInfo property field test" {       
+        $properties = ($commandInfo | Get-Member -MemberType NoteProperty)
+        $propertiesAsString =  $properties.name | out-string 
+        $propertiesAsString | Should MatchExactly 'CommandType' 
+        $propertiesAsString | Should MatchExactly 'Definition' 
+        $propertiesAsString | Should MatchExactly 'Module' 
+        $propertiesAsString | Should MatchExactly 'ModuleName' 
+        $propertiesAsString | Should MatchExactly 'Name' 
+        $propertiesAsString | Should MatchExactly 'ParameterSets' 
+    }
+
+    $testcases = @(
+                  @{observed = $commandInfo.Name; testname = "Name"; result = "Get-Date"}
+                  @{observed = $commandInfo.ModuleName; testname = "Name"; result = "Microsoft.PowerShell.Utility"}
+                  @{observed = $commandInfo.Module.Name; testname = "ModuleName"; result = "Microsoft.PowerShell.Utility"}
+                  @{observed = $commandInfo.CommandType; testname = "CommandType"; result = "Cmdlet"}
+                  @{observed = $commandInfo.Definition.Count; testname = "Definition"; result = 1}
+               )
+
+    It "Get-Command -ShowCommandInfo property test - <testname>" -TestCases $testcases{
+            param (
+            $observed,
+            $result
+        )
+        $observed | Should BeExactly $result
+    }
+
+
+    It "Get-Command -ShowCommandInfo ParameterSets property field test" {
+        $properties = ($commandInfo.ParameterSets[0] | Get-Member -MemberType NoteProperty)
+        $propertiesAsString =  $properties.name | out-string 
+        $propertiesAsString | Should MatchExactly 'IsDefault' 
+        $propertiesAsString | Should MatchExactly 'Name' 
+        $propertiesAsString | Should MatchExactly 'Parameters'
+    }
+
+    It "Get-Command -ShowCommandInfo Parameters property field test" {
+        $properties = ($commandInfo.ParameterSets[0].Parameters | Get-Member -MemberType NoteProperty)
+        $propertiesAsString =  $properties.name | out-string 
+        $propertiesAsString | Should MatchExactly 'HasParameterSet' 
+        $propertiesAsString | Should MatchExactly 'IsMandatory' 
+        $propertiesAsString | Should MatchExactly 'Name'
+        $propertiesAsString | Should MatchExactly 'ParameterType' 
+        $propertiesAsString | Should MatchExactly 'Position' 
+        $propertiesAsString | Should MatchExactly 'ValidParamSetValues'
+        $propertiesAsString | Should MatchExactly 'ValueFromPipeline'
+    }
+
 }