fix: FileDownload cross-platform support and target-path handling

CHANGELOG.md

@@ -7,6 +7,15 @@
 
 ## [Unreleased]
 
+### Added
+
+- `FileDownload` is now supported on all platforms (`core`, `macos`, `linux`); there was no Windows-only code blocking this (#98).
+- `FileDownload` relative `Target` paths are now rooted against `$PWD` before resolution, matching the intuitive expectation of callers (#49).
+
+### Fixed
+
+- `FileDownload` no longer misidentifies a directory-like `Target` (no file extension, or trailing slash) as a full file path when its parent happens to exist; the handler now uses a file-extension heuristic to distinguish file targets from container targets and creates the directory when it does not yet exist (#49).
+
 ## [0.4.1] - 2026-06-12
 
 ### Added
@@ -127,7 +136,7 @@
 ### Fixed
 
 - `Get-Dependency` operator-precedence bug when `DependencyType` is
   set inside `PSDependOptions`: parenthesization was incorrect, so the
   global default failed to apply to dependencies without an explicit
   type (#131, #173).
 - `Find-PSDependLocally` now consults *all* installed versions of a
@@ -138,7 +147,7 @@
   passing it to `Import-Module`, preventing failures when prerelease
   segments or `vX.Y.Z` tags appear in the resolved version (#140).
 - `Chocolatey` install path now passes `--yes` to `choco install`
   (previously the script contained the typo `--yess`), so installs
   no longer hang waiting on confirmation, and the surrounding code
   was tidied for readability (#174).
 - `Git` handler now uses the full `Dependency.Target` path when the

PSDepend/PSDependMap.psd1

@@ -27,7 +27,7 @@
     FileDownload    = @{
         Script      = 'FileDownload.ps1'
         Description = 'Download a file'
-        Supports    = 'windows'
+        Supports    = 'windows', 'core', 'macos', 'linux'
     }
 
     FileSystem      = @{
@@ -96,9 +96,9 @@
         Supports    = 'windows', 'core', 'macos', 'linux'
     }
 
     WindowsRSAT = @{
         Script = 'WindowsRSAT.ps1'
         Description = 'Install a WindowsRSAT PowerShell module using Add-WindowsCapability or Install-WindowsFeature, depending on OS'
         Supports = 'windows'
     }
 }

PSDepend/PSDependScripts/FileDownload.ps1

@@ -19,7 +19,7 @@
         Install: Install the dependency
 
     .EXAMPLE
         sqllite_dll = @{
             DependencyType = 'FileDownload'
             Source = 'https://github.com/RamblingCookieMonster/PSSQLite/blob/main/PSSQLite/x64/System.Data.SQLite.dll?raw=true'
             Target = 'C:\temp'
@@ -35,10 +35,10 @@
 
         # Downloads System.Data.SQLite.dll to C:\temp\sqlite.dll
 #>
 [cmdletbinding()]
 param(
     [PSTypeName('PSDepend.Dependency')]
     [psobject[]]
     $Dependency,
 
     [ValidateSet('Test', 'Install')]
@@ -46,7 +46,7 @@
 )
 
 function Parse-URLForFile {
     [cmdletbinding()]
     param($URL)
     # This will need work.  Assume leaf is file.  If CGI exists in leaf, assume it is after the file
     $FileName = $URL.split('/')[-1]
@@ -76,15 +76,16 @@
 
 # Act on target path....
 $ToInstall = $False # Anti pattern
+
+# Normalize relative paths against $PWD so callers don't get burned by cwd-dependent splits
+if (-not [IO.Path]::IsPathRooted($Target)) {
+    $Target = Join-Path $PWD $Target
+}
+
 $TargetParent = Split-Path $Target -Parent
 $PathToAdd = $Target
-if ( (Test-Path $TargetParent) -and -not (Test-Path $Target)) {
-    # They gave us a full path, don't parse the file name, use this!
-    $Path = $Target
-    $ToInstall = $True
-    Write-Verbose "Found parent [$TargetParent], not target [$Target], assuming this is target file path"
-}
-elseif (Test-Path $Target -PathType Leaf) {
+
+if (Test-Path $Target -PathType Leaf) {
     # File exists.  We should download to temp spot, compare hashes, take action as appropriate.
     # For now, skip the file.
     Write-Verbose "Skipping existing file [$Target]"
@@ -93,16 +94,26 @@
     }
     $PathToAdd = Split-Path $Target -Parent
 }
-elseif (-not (Test-Path $Target)) {
-    # They gave us something that doesn't look like a new container for a new or existing file. Wat?
-    Write-Error "Could not find target path [$Target]"
-    if ($PSDependAction -contains 'Test') {
-        return $False
+elseif ([IO.Path]::GetExtension($Target) -and -not (Test-Path $Target -PathType Container)) {
+    # Target has a file extension — treat as a full destination file path
+    if (-not (Test-Path $TargetParent)) {
+        Write-Error "Could not find parent path [$TargetParent] for target [$Target]"
+        if ($PSDependAction -contains 'Test') {
+            return $False
+        }
+    }
+    else {
+        $Path = $Target
+        $ToInstall = $True
+        Write-Verbose "Target has extension, treating as file path [$Target]"
     }
 }
 else {
+    # No extension (or already a container) — treat target as a directory
     Write-Verbose "[$Target] is a container, creating path to file"
-    # We have a target container, now find the name
+    if (-not (Test-Path $Target)) {
+        New-Item -ItemType Directory -Path $Target -Force | Out-Null
+    }
     If ($Name) {
         # explicit name
         $FileName = $Name
@@ -138,6 +149,6 @@
 }
 
 if ($Dependency.AddToPath) {
-    Write-Verbose "Setting PATH to`n$($PathToAdd, $env:PATH -join ';' | Out-String)"
+    Write-Verbose "Setting PATH to`n$($PathToAdd, $env:PATH -join [IO.Path]::PathSeparator | Out-String)"
     Add-ToItemCollection -Reference Env:\Path -Item $PathToAdd
 }

Tests/FileDownload.Type.Tests.ps1

@@ -71,4 +71,45 @@
         }
         $result | Should -Be $true
     }
+
+    It 'Creates a new directory and downloads into it when Target has no extension and does not exist' {
+        $newDir = Join-Path (New-Item 'TestDrive:/dl5base' -ItemType Directory -Force).FullName 'newcontainer'
+        $dep = New-PSDependFixture -DependencyName 'https://example.com/sample.dll' -DependencyType 'FileDownload' -Target $newDir
+        InModuleScope PSDepend -Parameters @{ Dep = $dep; ScriptPath = $script:ScriptPath; T = $newDir } {
+            & $ScriptPath -Dependency $Dep
+        }
+        Should -Invoke -CommandName Get-WebFile -ModuleName PSDepend -Times 1 -Exactly -ParameterFilter {
+            $URL -eq 'https://example.com/sample.dll' -and ($Path -like "*newcontainer*sample.dll")
+        }
+        Test-Path $newDir -PathType Container | Should -Be $true
+    }
+
+    It 'Treats Target as a full file path when it has a file extension and parent exists' {
+        $targetDir = (New-Item 'TestDrive:/dl6' -ItemType Directory -Force).FullName
+        $targetFile = Join-Path $targetDir 'out.dll'
+        $dep = New-PSDependFixture -DependencyName 'https://example.com/other.dll' -DependencyType 'FileDownload' -Target $targetFile
+        InModuleScope PSDepend -Parameters @{ Dep = $dep; ScriptPath = $script:ScriptPath } {
+            & $ScriptPath -Dependency $Dep
+        }
+        Should -Invoke -CommandName Get-WebFile -ModuleName PSDepend -Times 1 -Exactly -ParameterFilter {
+            $URL -eq 'https://example.com/other.dll' -and $Path -eq $targetFile
+        }
+    }
+
+    It 'Roots a relative Target against $PWD and downloads to it' {
+        $baseDir = (New-Item 'TestDrive:/relbase' -ItemType Directory -Force).FullName
+        Push-Location $baseDir
+        try {
+            $dep = New-PSDependFixture -DependencyName 'https://example.com/sample.dll' -DependencyType 'FileDownload' -Target 'subdir'
+            InModuleScope PSDepend -Parameters @{ Dep = $dep; ScriptPath = $script:ScriptPath } {
+                & $ScriptPath -Dependency $Dep
+            }
+            Should -Invoke -CommandName Get-WebFile -ModuleName PSDepend -Times 1 -Exactly -ParameterFilter {
+                $Path -like "*subdir*sample.dll"
+            }
+        }
+        finally {
+            Pop-Location
+        }
+    }
 }