Improve Windows installer command output

Author: mbv06

install-windows.ps1

@@ -56,6 +56,57 @@ function Wait-BeforeExit {
     }
 }
 
+function Format-CommandForDisplay {
+    param(
+        [Parameter(Mandatory = $true)]
+        [string]$FilePath,
+
+        [Parameter()]
+        [string[]]$Arguments = @()
+    )
+
+    $parts = @($FilePath) + @($Arguments)
+    $quotedParts = foreach ($part in $parts) {
+        if ($part -match '[\s"]') {
+            '"' + ($part -replace '"', '\"') + '"'
+        }
+        else {
+            $part
+        }
+    }
+
+    return ($quotedParts -join ' ')
+}
+
+function Invoke-NativeCommand {
+    param(
+        [Parameter(Mandatory = $true)]
+        [string]$FilePath,
+
+        [Parameter()]
+        [string[]]$Arguments = @(),
+
+        [Parameter()]
+        [string]$FailureMessage = 'Command failed.'
+    )
+
+    Write-Host ("Running: {0}" -f (Format-CommandForDisplay -FilePath $FilePath -Arguments $Arguments)) -ForegroundColor DarkGray
+    $output = & $FilePath @Arguments 2>&1
+    $exitCode = $LASTEXITCODE
+
+    if ($output) {
+        foreach ($line in @($output)) {
+            Write-Host $line
+        }
+    }
+
+    if ($exitCode -ne 0) {
+        Die $FailureMessage
+    }
+
+    return @($output)
+}
+
 function Die($Message) {
     Write-Host "Error: $Message" -ForegroundColor Red
     Wait-BeforeExit
@@ -146,24 +197,19 @@ then run this installer again.
     Write-Host "Using Python: $python"
 
     Log 'Checking built-in venv support'
-    & $python -m venv --help > $null 2>&1
-    if ($LASTEXITCODE -ne 0) {
-        Die 'This Python does not support the built-in venv module. Install a full Python distribution and try again.'
-    }
+    Invoke-NativeCommand -FilePath $python -Arguments @('-c', 'import venv') -FailureMessage 'This Python does not support the built-in venv module. Install a full Python distribution and try again.' | Out-Null
 
     Log 'Creating private Python environment'
     if (-not (Test-Path $AppHome)) {
         New-Item -ItemType Directory -Path $AppHome -Force | Out-Null
     }
-    & $python -m venv $VenvDir
-    if ($LASTEXITCODE -ne 0) { Die 'Failed to create virtual environment.' }
+    Invoke-NativeCommand -FilePath $python -Arguments @('-m', 'venv', $VenvDir) -FailureMessage 'Failed to create virtual environment.' | Out-Null
 
     $venvPython = Join-Path $ScriptsDir 'python.exe'
 
     Log 'Installing / upgrading Slicer URI Bridge'
-    & $venvPython -m pip install --upgrade pip 2>&1 | Out-Null
-    & $venvPython -m pip install --upgrade $ProjectSpec
-    if ($LASTEXITCODE -ne 0) { Die 'pip install failed.' }
+    Invoke-NativeCommand -FilePath $venvPython -Arguments @('-m', 'pip', 'install', '--upgrade', 'pip') -FailureMessage 'Failed to upgrade pip.' | Out-Null
+    Invoke-NativeCommand -FilePath $venvPython -Arguments @('-m', 'pip', 'install', '--upgrade', $ProjectSpec) -FailureMessage 'pip install failed.' | Out-Null
 
     Log 'Adding Scripts directory to user PATH'
     $added = Add-ToUserPath $ScriptsDir
@@ -175,10 +221,10 @@ then run this installer again.
     }
 
     Log 'Creating config if needed'
-    & $BridgeExe init-config 2>&1 | Out-Null
+    Invoke-NativeCommand -FilePath $BridgeExe -Arguments @('init-config') -FailureMessage 'Failed to create config.' | Out-Null
 
     Log 'Registering URI handlers'
-    & $BridgeExe register --auto
+    Invoke-NativeCommand -FilePath $BridgeExe -Arguments @('register', '--auto') -FailureMessage 'Failed to register URI handlers.' | Out-Null
 
     $configDir = Join-Path $env:APPDATA 'slicer-uri-bridge'