🐛 🔧 Fix outstanding issues in koan topics (#347)

* 🔧 Resolve issues in AboutModules

Fixes #342

* 🔧 Fix issues in AboutTeeObject

Fixes #341

Also added a new koan to show when the variable is created

* 🔧 Fix issues in AboutMeasureObject

Fixes #340

* 🔧 Fix issues in AboutSelectObject

Fixes #339

Fixes #337

* 🔧 Fix issue in AboutAssignmentAndArithmetic

Fixes #334

* 🔧 Fix issues in AboutDiscovery

Fixes #335

Fixes #332

* 🔧 ♻️ Fix up AboutArrays

Fixes #330

* 🔧 Fix missing variable reference

* 🎨 Update format of array declaration

PSKoans/Koans/Cmdlets 1/AboutDiscovery.Koans.ps1

@@ -31,7 +31,10 @@ Describe 'Get-Help' {
             $HelpInfo = Get-Help 'Get-Help'
             $GetHelpParams = $HelpInfo.Parameters.Parameter.Name
 
-            # Using the information from Get-Help, fill in a few of the available parameter names for the cmdlet.
+            <#
+                Using the information from Get-Help, fill in a few of the available parameter names for the cmdlet.
+                Note that the specific parameters available may depend on your version of PowerShell.
+            #>
             $ParamNames = @(
                 '____'
                 'Examples'
@@ -41,7 +44,11 @@ Describe 'Get-Help' {
                 '____'
             )
 
-            $ParamNames | Group-Object | Where-Object Count -gt 1 | Should -BeNullOrEmpty
+            $ParamNames |
+                Group-Object |
+                Where-Object Count -gt 1 |
+                Should -BeNullOrEmpty -Because 'you need to enter unique parameter names'
+
             $ParamNames | Should -BeIn $GetHelpParams
         }
 
@@ -211,6 +218,6 @@ Describe 'Get-Command' {
         $First4Commands = $KoanCommands | Select-Object -First 4
 
         __ | Should -Be $KoanCommands.Count
-        @('____', '____', '____', '____') | Should -Be $KoanCommands.Name
+        @('____', '____', '____', '____') | Should -Be $First4Commands.Name
     }
 }

PSKoans/Koans/Cmdlets 1/AboutMeasureObject.Koans.ps1

@@ -17,7 +17,7 @@ Describe 'Measure-Object' {
             665, 154, 943, 35, 391, 816, 420, 229, 3, 938
         )
 
-        $Files = Get-ChildItem -Path $home -Recurse -Depth 2
+        $Files = Get-ChildItem -Path $HOME -Recurse -Depth 2
     }
 
     It 'can count objects' {
@@ -76,12 +76,26 @@ Describe 'Measure-Object' {
 
     It 'can operate on object properties' {
         $Data = $Files.BaseName | Measure-Object -Property Length -Sum -Average
+
+        # Averages can have a lot of decimal places, so we'll round to just 4 decimal places.
+        $Average = [math]::Round($Data.Average, 4)
+
         __ | Should -Be $Data.Sum
-        __ | Should -Be $Data.Average
+        __ | Should -Be $Average
     }
 
     It 'can measure text lines, characters, and words of strings' {
-        $Text = Get-Content "$(Get-PSKoanLocation)/Foundations/AboutTheStockChallenge.Koans.ps1"
+        $Text = '
+            Two monks were arguing about the temple flag waving in the wind.
+            One said, "The flag moves."
+            The other said, "The wind moves."
+            They argued back and forth but could not agree.
+
+            Hui-neng, the sixth patriarch, said:
+            "Gentlemen! It is not the flag that moves. It is not the wind that moves. It is your mind that moves."
+
+            The two monks were struck with awe.
+        '
         $Data = $Text | Measure-Object -Line -Word -Character
 
         __ | Should -Be $Data.Lines

PSKoans/Koans/Cmdlets 1/AboutModules.Koans.ps1

@@ -33,11 +33,13 @@ Describe 'Get-Module' {
 
         $FirstThreeModules = $Modules | Select-Object -First 3
         $VersionOfThirdModule = $FirstThreeModules[2].Version
-        $TypeOf6thModule = $Modules[5].ModuleType
+        $TypeOfLastModule = $Modules |
+            Select-Object -Last 1 |
+            ForEach-Object -MemberName ModuleType
 
         @('____', '____', '____') | Should -Be $FirstThreeModules.Name
         '____' | Should -Be $VersionOfThirdModule
-        '____' | Should -Be $TypeOf6thModule
+        '____' | Should -Be $TypeOfLastModule
     }
 
     It 'can filter by module name' {
@@ -117,7 +119,7 @@ Describe 'New-Module' {
         a module in-memory without needing a file on disk.
     #>
     BeforeAll {
-        $Module = New-Module -Name 'PSKoans_TestModule' -ScriptBlock {} -ArgumentList
+        $Module = New-Module -Name 'PSKoans_TestModule' -ScriptBlock {}
     }
 
     It 'creates a dynamic module object' {
@@ -179,7 +181,7 @@ Describe 'Import-Module' {
         }
 
         It 'does not produce output' {
-            Import-Module 'TestDrive:\TestModule.psm1' | Should -Be NullOrEmpty
+            Import-Module 'TestDrive:\TestModule.psm1' | Should -BeNullOrEmpty
         }
 
         It 'imports the module into the current session' {

PSKoans/Koans/Cmdlets 1/AboutSelectObject.Koans.ps1

@@ -18,7 +18,7 @@ Describe 'Select-Object' {
             new custom object using those properties.
         #>
 
-        $Selected = Get-Proces -Id $PID | Select-Object Name, ID, Path
+        $Selected = Get-Process -Id $PID | Select-Object Name, ID, Path
 
         @('____', '____', 'Path') | Should -Be $Selected.PSObject.Properties.Name
 
@@ -50,7 +50,7 @@ Describe 'Select-Object' {
 
         $Folder = Get-Item -Path $PSHome
 
-        $Selected.GetType().FullName | Should -BeOfType [System.IO.Directoryinfo]
+        $Folder | Should -BeOfType [____]
 
         'System.IO.Directoryinfo' | Should -BeIn $Folder.PSTypeNames
 
@@ -109,9 +109,11 @@ Describe 'Select-Object' {
     It 'can ignore duplicate objects' {
         # Select-Object can be used to create a unique list.
 
-        $Array = '6', '1', '4', '8', '7', '5', '3', '9', '2', '3', '2', '1', '5', '1', '6',
-            '2', '8', '4', '7', '3', '1', '2', '6', '3', '7', '1', '4', '5', '2', '1', '3',
-            '6', '2', '5', '1', '4'
+        $Array = @(
+            '6', '1', '4', '8', '7', '5', '3', '9', '2', '3', '2', '1', '5', '1', '6'
+            '2', '8', '4', '7', '3', '1', '2', '6', '3', '7', '1', '4', '5', '2', '1'
+            '3', '6', '2', '5', '1', '4'
+        )
 
         $UniqueItems = $Array | Select-Object -Unique
         @('6', '__', '4', '8', '__', '__', '3', '__', '2') | Should -Be $UniqueItems
@@ -244,7 +246,7 @@ Describe 'Select-Object' {
         $Selected = Get-Process -Id $PID | Select-Object @(
             'Name'
             'Id'
-            @{ n = 'Size'; e = { (Get-Item $_.Path).Length } }
+            @{ Name = 'RunningTime'; Expression = { (Get-Date) - $_.StartTime } }
         )
 
         $Selected.____ | Should -BeOfType [TimeSpan]
@@ -294,6 +296,6 @@ Describe 'Select-Object' {
             System.Management.Automation.PSObject. It is named as it is because it creates a custom object.
         #>
 
-        [PSCustomObject] | Should -Be [System.Management.Automation.PSObject]
+        [PSCustomObject].FullName | Should -Be System.Management.Automation.PSObject
     }
 }

PSKoans/Koans/Cmdlets 1/AboutTeeObject.Koans.ps1

@@ -19,17 +19,42 @@ Describe 'Tee-Object' {
     It 'can store the object(s) into a variable' {
         # Note the variable name is given as a string, without the $ prefix.
         $Values = 'alpha', 'beta', 'gamma'
-        @('____', '____', '____', '____') | Tee-Object -Variable 'Numbers' | Should -Be $Values
+
+        @('____', 'beta', '____') |
+            Tee-Object -Variable 'Numbers' |
+            Should -Be $Values
+
+        '____' | Should -Be $Numbers[0]
         '____' | Should -Be $Numbers[1]
+        'gamma' | Should -Be $Numbers[2]
+    }
+
+    It 'does not create the variable until the pipeline is completed' {
+        $Values = 1..10
+
+        $Values |
+            Tee-Object -Variable Test |
+            ForEach-Object { $Test | Should -BeNullOrEmpty }
+
+        $Test | Should -Not -BeNullOrEmpty
+        $____ | Should -Be $Values
     }
 
     It 'can also store the object(s) into a file' {
-        $File = New-TemporaryFile
+        <#
+            $TestDrive, or TestDrive:, refers to a temporary location that is automatically
+            cleaned out by Pester when the tests are concluded.
+        #>
+        $File = New-Item -Path "$TestDrive/TeeObjectTest.txt"
+
+        1..5 |
+            ForEach-Object { "{0:N2}" -f (1 / $_) } |
+            Tee-Object -FilePath $File.FullName |
+            Out-Null
 
-        $Output = 1..5 | ForEach-Object { "{0:N2}" -f (1 / $_) } | Tee-Object -FilePath $File.FullName
         $Stored = Get-Content -Path $File
 
         # Text files can only store string data, so be careful storing arbitrary data to files like this.
-        @('__', '__', '3', '__', '__') | Should -Be $Stored
+        @('__', '__', '0.33', '__', '__') | Should -Be $Stored
     }
 }

PSKoans/Koans/Foundations/AboutArrays.Koans.ps1

@@ -27,13 +27,13 @@ Describe 'Arrays' {
         #>
         $Ages[0] | Should -Be 12
         __ | Should -Be $Ages[3]
+    }
 
+    It 'can be created with the @() operator' {
         <#
             The array subexpression operator @() is used to create an array from multiple values
-            or expressions. Within the parentheses, either commas, semicolons, or even line
-            breaks can be used to divide array elements. Although in many cases in PowerShell
-            an expression that only returns one value will not become an array, this operator
-            forces the value or object to be wrapped in an array.
+            or expressions. Within the parentheses, you can use commas, semicolons, and even line
+            breaks to divide array elements.
         #>
         $Names = @(
             'Steve'
@@ -44,6 +44,15 @@ Describe 'Arrays' {
 
         # Where is index 4 in the above array?
         __ | Should -Be $Names[4]
+
+        <#
+            Although in many cases in PowerShell, an expression that only returns one value will
+            not become an array, this operator forces the value or object to be wrapped in an array
+            if the result is not already an array; it guarantes the result will be an array.
+        #>
+        $Array = @( 10 )
+
+        $Array.GetType().FullName | Should -Be System.____
     }
 
     It 'is a fixed size collection; elements cannot be added or removed' {
@@ -235,9 +244,13 @@ Describe 'Arrays' {
             The base type of Object[], Char[], and other fixed size array types is the System.Array
             type, or [Array].
 
-            The [Array] type describes the Length property (aliased to Count), as well as other methods
-            which can be used to work with the array.
+            The [Array] type describes the Length property (which is also aliased to Count in PowerShell),
+            as well as other methods which can be used to work with the array.
+        #>
+    }
 
+    It 'allows you to check if something is contained within it' {
+        <#
             The available methods can be seen with Get-Member:
 
                 Get-Member -InputObject @()

PSKoans/Koans/Foundations/AboutAssignmentAndArithmetic.Koans.ps1

@@ -179,35 +179,55 @@ Describe 'Assignment/Arithmetic Combination Operators' {
 
     It 'is a bit unwieldy to assign and increment without combination operators' {
         $Value = 5
+
         $Value = $Value + 5
         __ | Should -Be $Value
     }
 
     It 'is possible to combine assignment and addition' {
         $Value = 12
+
         $Value += 7
         __ | Should -Be $Value
     }
 
     It 'is also possible to combine subtraction with assignment' {
+        $Value = 19
+
         $Value -= 3
         __ | Should -Be $Value
     }
 
     It 'works the same way with division' {
+        $Value = 16
+
         $Value /= 2
-        $Value | Should -Be 8
+        __ | Should -Be $Value
     }
 
     It 'works with multiplication as well' {
+        $Value = 8
+
         $Value *= 3
         __ | Should -Be $Value
     }
 
     It 'even works with modulus' {
-        # Modulus hasn't been left out, either.
         $Value = 12
+
         $Value %= 4
         __ | Should -Be $Value
     }
+
+    It 'can get a bit confusing to follow' {
+        $Value = __
+
+        $Value /= 3
+        $Value %= 5
+        $Value += 4
+        $Value *= 7
+        $Value -= 7
+
+        $Value | Should -Be 42
+    }
 }