move source code to public

images/macos/helpers/Common.Helpers.psm1

@@ -0,0 +1,76 @@
+function Get-CommandResult {
+    param (
+        [Parameter(Mandatory=$true)]
+        [string] $Command,
+        [switch] $Multiline
+    )
+    # Bash trick to suppress and show error output because some commands write to stderr (for example, "python --version")
+    $stdout = & bash -c "$Command 2>&1"
+    $exitCode = $LASTEXITCODE
+    return @{
+        Output = If ($Multiline -eq $true) { $stdout } else { [string]$stdout }
+        ExitCode = $exitCode
+    }
+}
+
+# Gets path to the tool, analogue of 'which tool'
+function Get-WhichTool($tool) {
+    return (Get-Command $tool).Path
+}
+
+# Gets value of environment variable by the name
+function Get-EnvironmentVariable($variable) {
+    return [System.Environment]::GetEnvironmentVariable($variable)
+}
+
+# Returns the object with information about current OS
+# It can be used for OS-specific tests 
+function Get-OSVersion {
+    $osVersion = [Environment]::OSVersion
+    return [PSCustomObject]@{
+        Version = $osVersion.Version
+        Platform = $osVersion.Platform
+        IsHighSierra = $osVersion.Version.Major -eq 17
+        IsMojave = $osVersion.Version.Major -eq 18
+        IsCatalina = $osVersion.Version.Major -eq 19
+        IsBigSur = $osVersion.Version.Major -eq 20
+        IsLessThanCatalina = $osVersion.Version.Major -lt 19
+        IsLessThanBigSur = $osVersion.Version.Major -lt 20
+        IsHigherThanMojave = $osVersion.Version.Major -gt 18 
+    }
+}
+
+function Get-ChildItemWithoutSymlinks {
+    param (
+        [Parameter(Mandatory)]
+        [string] $Path,
+        [string] $Filter
+    )
+
+    $files = Get-ChildItem -Path $Path -Filter $Filter
+    $files = $files | Where-Object { !$_.LinkType } # cut symlinks
+    return $files
+}
+
+# Get the value of specific toolset node
+# Example, invoke `Get-ToolsetValue "xamarin.bundles"` to get value of `$toolsetJson.xamarin.bundles`
+function Get-ToolsetValue {
+    param (
+        [Parameter(Mandatory = $true)]
+        [string] $KeyPath
+    )
+    $toolsetPath = Join-Path $env:HOME "image-generation" "toolset.json"
+    $jsonNode = Get-Content -Raw $toolsetPath | ConvertFrom-Json
+
+    $pathParts = $KeyPath.Split(".")
+    # try to walk through all arguments consequentially to resolve specific json node 
+    $pathParts | ForEach-Object {
+        $jsonNode = $jsonNode.$_
+    }
+    return $jsonNode
+}
+
+function Get-ToolcachePackages {
+    $toolcachePath = Join-Path $env:HOME "image-generation" "toolcache.json"
+    return Get-Content -Raw $toolcachePath | ConvertFrom-Json
+}