fix(release): harden cross-platform offline installers (#131)

scripts/test-offline-install.ps1

@@ -0,0 +1,65 @@
+# Smoke-test Windows offline upgrade rollback with tiny local archives.
+[CmdletBinding()]
+param()
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+$RepoRoot = Split-Path -Parent $PSScriptRoot
+$Installer = Join-Path $RepoRoot "install.ps1"
+$WorkDir = Join-Path ([IO.Path]::GetTempPath()) "penguin-offline-install-tests-$PID"
+$OriginalPath = $env:Path
+$OriginalOs = $env:OS
+
+function Assert-True([bool]$Condition, [string]$Message) {
+  if (-not $Condition) { throw "test failure: $Message" }
+}
+
+function New-FixtureArchive([string]$Name, [bool]$Fails = $false) {
+  $SourceDir = Join-Path $WorkDir "$Name-source"
+  $PenguinDir = Join-Path $SourceDir "penguin"
+  New-Item -ItemType Directory -Path (Join-Path $PenguinDir "bin") -Force | Out-Null
+  New-Item -ItemType Directory -Path (Join-Path $PenguinDir "lib") -Force | Out-Null
+  $VersionLines = if ($Fails) {
+    @("echo fixture runtime failure 1>&2", "exit /b 42")
+  } else {
+    @("echo fixture-old", "exit /b 0")
+  }
+  @("@echo off", "if `"%~1`"==`"--version`" (") + $VersionLines + @(")", "exit /b 0") |
+    Set-Content -LiteralPath (Join-Path $PenguinDir "bin\penguin.cmd") -Encoding ascii
+  "fixture" | Set-Content -LiteralPath (Join-Path $PenguinDir "lib\fixture.txt") -Encoding ascii
+  @{ schemaVersion = 1; target = "win32-x64" } | ConvertTo-Json -Compress |
+    Set-Content -LiteralPath (Join-Path $PenguinDir "package-manifest.json") -Encoding ascii
+  $Archive = Join-Path $WorkDir "$Name.zip"
+  Compress-Archive -Path $PenguinDir -DestinationPath $Archive -CompressionLevel Fastest
+  $Hash = (Get-FileHash -LiteralPath $Archive -Algorithm SHA256).Hash
+  "$Hash  $([IO.Path]::GetFileName($Archive))" |
+    Set-Content -LiteralPath "$Archive.sha256" -Encoding ascii
+  return $Archive
+}
+
+try {
+  New-Item -ItemType Directory -Path $WorkDir -Force | Out-Null
+  # Keep the fixture test away from the runner's user registry Path.
+  $env:OS = "PenguinInstallerFixtureTest"
+  $InstallDir = Join-Path $WorkDir "installed"
+  $GoodArchive = New-FixtureArchive "valid"
+  & $Installer -InstallDir $InstallDir -ArchivePath $GoodArchive *>&1 | Out-Null
+
+  $FailedArchive = New-FixtureArchive "failure" $true
+  $Failed = $false
+  try {
+    & $Installer -InstallDir $InstallDir -ArchivePath $FailedArchive *>&1 | Out-Null
+  } catch {
+    $Failed = $true
+  }
+  Assert-True $Failed "failing Windows upgrade unexpectedly succeeded"
+  $Version = & (Join-Path $InstallDir "bin\penguin.cmd") --version
+  Assert-True ($Version -eq "fixture-old") "previous Windows installation was not restored"
+  Write-Host "Windows offline rollback smoke test passed."
+} finally {
+  $env:Path = $OriginalPath
+  $env:OS = $OriginalOs
+  if (Test-Path -LiteralPath $WorkDir) {
+    Remove-Item -LiteralPath $WorkDir -Recurse -Force
+  }
+}