Extract .pkg files automatically via --packDir

src/vpk/Velopack.Packaging.Unix/Commands/OsxPackCommandRunner.cs

@@ -13,13 +13,25 @@ public class OsxPackCommandRunner : PackageBuilder<OsxPackOptions>
     {
     }
 
+    protected override string ExtractPackDir(string packDirectory)
+    {
+        if (packDirectory.EndsWith(".pkg", StringComparison.OrdinalIgnoreCase)) {
+            Log.Warn("Extracting application bundle from .pkg installer. This is not recommended for production use.");
+            var dir = Path.Combine(TempDir.FullName, "pkg_extract");
+            var helper = new OsxBuildTools(Log);
+            return helper.ExtractPkgToAppBundle(packDirectory, dir);
+        }
+        
+        return packDirectory;
+    }
+
     protected override Task<string> PreprocessPackDir(Action<int> progress, string packDir)
     {
         var packTitle = Options.PackTitle ?? Options.PackId;
         var dir = TempDir.CreateSubdirectory(packTitle + ".app");
         bool deleteAppBundle = false;
-        string appBundlePath = Options.PackDirectory;
-        if (!Options.PackDirectory.EndsWith(".app", StringComparison.OrdinalIgnoreCase)) {
+        string appBundlePath = packDir;
+        if (!packDir.EndsWith(".app", StringComparison.OrdinalIgnoreCase)) {
             appBundlePath = new OsxBundleCommandRunner(Log).Bundle(Options);
             deleteAppBundle = true;
         }

src/vpk/Velopack.Packaging.Unix/OsxBuildTools.cs

@@ -262,4 +262,33 @@ exit 0
         Log.Debug($"Creating ditto bundle '{outputZip}'");
         Log.Debug(Exe.InvokeAndThrowIfNonZero("ditto", args, null));
     }
+    
+    public string ExtractPkgToAppBundle(string pkgFile, string extractionTmpPath)
+    {
+        if (!File.Exists(pkgFile)) {
+            throw new ArgumentException("Package file does not exist: " + pkgFile);
+        }
+        
+        Log.Debug($"Extracting '{pkgFile}' to '{extractionTmpPath}'");
+        
+        var args = new List<string> {
+            "--expand-full",
+            pkgFile,
+            extractionTmpPath,
+        };
+
+        Log.Debug(Exe.InvokeAndThrowIfNonZero("pkgutil", args, null));
+        
+        IEnumerable<string> appPaths = Directory.EnumerateDirectories(extractionTmpPath, "*.app", SearchOption.AllDirectories).ToArray();
+
+        if (appPaths.Count() > 1) {
+            throw new Exception("The package contains more than one .app bundle. This is not supported.");
+        }
+        
+        if (!appPaths.Any()) {
+            throw new Exception("The package does not contain an .app bundle.");
+        }
+        
+        return appPaths.First();
+    }
 }

src/vpk/Velopack.Packaging/PackageBuilder.cs

@@ -64,11 +64,17 @@ public abstract class PackageBuilder<T> : ICommand<T>
                 throw new UserInfoException($"There is a release in channel {channel} which is equal or greater to the current version {options.PackVersion}. Please increase the current package version or remove that release.");
             }
         }
+        
+        using var _1 = TempUtil.GetTempDirectory(out var pkgTempDir);
+        TempDir = new DirectoryInfo(pkgTempDir);
 
         var packId = options.PackId;
         var packDirectory = options.PackDirectory;
         var packVersion = options.PackVersion;
 
+        // extract pre-bundled apps as required (eg. .AppImage or .pkg)
+        packDirectory = ExtractPackDir(packDirectory);
+
         // check that entry exe exists
         var mainExeName = options.EntryExecutableName ?? options.PackId;
         var mainSearchPaths = GetMainExeSearchPaths(packDirectory, mainExeName);
@@ -90,9 +96,6 @@ public abstract class PackageBuilder<T> : ICommand<T>
 
         MainExePath = mainExePath;
         options.EntryExecutableName = Path.GetFileName(mainExePath);
-
-        using var _1 = TempUtil.GetTempDirectory(out var pkgTempDir);
-        TempDir = new DirectoryInfo(pkgTempDir);
         Options = options;
 
         ConcurrentBag<(string from, string to)> filesToCopy = new();
@@ -170,6 +173,8 @@ public abstract class PackageBuilder<T> : ICommand<T>
         });
     }
 
+    protected virtual string ExtractPackDir(string packDirectory) => packDirectory;
+
     protected abstract string[] GetMainExeSearchPaths(string packDirectory, string mainExeName);
 
     protected virtual string GenerateNuspecContent()

src/vpk/Velopack.Vpk/Commands/_PackCommand.cs

@@ -15,7 +15,7 @@ public abstract class PackCommand : PlatformCommand
 
     public string PackDirectory { get; private set; }
 
-    protected CliOption<DirectoryInfo> PackDirectoryOption { get; private set; }
+    protected CliOption<FileSystemInfo> PackDirectoryOption { get; private set; }
 
     public string PackAuthors { get; private set; }
 
@@ -69,11 +69,10 @@ public abstract class PackCommand : PlatformCommand
             .SetRequired()
             .RequiresSemverCompliant();
 
-        PackDirectoryOption = AddOption<DirectoryInfo>((v) => PackDirectory = v.ToFullNameOrNull(), "--packDir", "-p")
+        PackDirectoryOption = AddOption<FileSystemInfo>((v) => PackDirectory = v.ToFullNameOrNull(), "--packDir", "-p")
             .SetDescription("Directory containing application files for release.")
             .SetArgumentHelpName("DIR")
-            .SetRequired()
-            .MustNotBeEmpty();
+            .SetRequired();
 
         PackAuthorsOption = AddOption<string>((v) => PackAuthors = v, "--packAuthors")
             .SetDescription("Company name or comma-delimited list of authors.")