SupportsShouldProcess in Set-Function, implement some PSScriptAnalyzer suggestions

Author: Pascal-So

Aliases.ps1

@@ -1,15 +1,9 @@
-<#
-.SYNOPSIS
-Aliases ¯\_(ツ)_/¯
-#>
+. "$PSScriptRoot\Set-Function.ps1"
 
-# Make sure Define-Command is available
-. "$PSScriptRoot\Define-Function.ps1"
-
-Define-Function ga {git add @ARGS}    -Force
-Define-Function gd {git diff @ARGS}   -Force
-Define-Function gc {git commit @ARGS} -Force
-Define-Function gs {git status @ARGS} -Force
+Set-Function ga {git add @ARGS}
+Set-Function gd {git diff @ARGS}
+Set-Function gc {git commit @ARGS}
+Set-Function gs {git status @ARGS}
 
 Function Find-ProgramPath ([String] $name, [uint32] $depth=2) {
     Function find-in([String] $path) {

Define-Function.ps1

@@ -0,0 +1,52 @@
+function Set-Function {
+    <#
+    .SYNOPSIS
+        Create a PowerShell function
+
+    .DESCRIPTION
+        This is useful if you want to create a function where the name
+        is given by an arbitrary string expression.
+
+        When defining a function with the PowerShell "Function" keyword
+        then a fixed name has to be given.
+
+    .PARAMETER RemoveAlias
+        If an alias exists with the given name, remove it. This is neccessary because
+        aliases have higher precedence than functions.
+
+    .EXAMPLE
+        Set-Function "${funname}-asdf" {Write-Output "Hello World"}
+
+    .EXAMPLE
+        Set-Function "existingfunction" {Write-Output "new implementation"} -Confirm
+    #>
+    [CmdletBinding(SupportsShouldProcess, ConfirmImpact = 'Medium')]
+    param(
+        [Parameter(Mandatory)] [String] $Name,
+        [Parameter(Mandatory)] [ScriptBlock] $Implementation,
+        [Switch] $NoRemoveAlias
+    )
+
+    # Check if the function already exists
+    if (Test-Path "Function:$Name") {
+        if ($PSCmdlet.ShouldProcess("Function:$Name", 'Overwrite the function.')) {
+            Remove-Item -Path "Function:$Name" -Confirm:$false
+        } else {
+            return
+        }
+    }
+
+    # Check if an alias with this name exists
+    if ((-not $NoRemoveAlias) -and (Test-Path "Alias:$Name")) {
+        if ($PSCmdlet.ShouldProcess("Alias:$Name", 'Remove the alias.')) {
+            Remove-Item "Alias:$Name" -Force -Confirm:$False
+
+            # We need to run this a second time because if a local alias exists
+            # inside the function scope then the first time we only remove
+            # the local alias, the second time the global alias is removed.
+            if (Test-Path "Alias:$Name") {Remove-Item "Alias:$Name" -Force}
+        }
+    }
+
+    New-Item -Path "Function:global:$Name" -Value $Implementation -Confirm:$False | Out-Null
+}

Set-Function.ps1

@@ -13,7 +13,7 @@ Function Search-Google {
         $query = 'https://www.google.com/search?q='
         foreach ($arg in $ARGS) { $query += "${arg}+" }
         $url = $query.Substring(0, $query.Length - 1)
-        start "$url"
+        Start-Process "$url"
 }
 
 Set-Alias glg Search-Google