Fix self update macOS (#440)

* Fix the self update for macOS so that the installer is executed

* Add compatible configuration versions to init command for updates

* Add test for a migration for the current swiftly version to capture branching problems

* Permit self-updates to identical version using the hidden --to-version option.

Author: cmcgee1024

Sources/MacOSPlatform/MacOS.swift

@@ -117,10 +117,10 @@ public struct MacOS: Platform {
 
         if ctx.mockedHomeDir == nil {
             await ctx.message("Extracting the swiftly package...")
-            _ = sys.installer(
+            try await sys.installer(
                 .pkg(archive),
                 .target("CurrentUserHomeDirectory")
-            )
+            ).run(self)
             try? await sys.pkgutil(.volume(userHomeDir)).forget(pkg_id: "org.swift.swiftly").run(self)
         } else {
             let installDir = userHomeDir / ".swiftly"

Sources/Swiftly/Init.swift

@@ -3,6 +3,30 @@ import Foundation
 import SwiftlyCore
 import SystemPackage
 
+public enum SwiftlyVersionMigration {
+    case exact(SwiftlyVersion)
+    case minor(SwiftlyVersion)
+
+    public func matches(_ version: SwiftlyVersion) -> Bool {
+        switch self {
+        case let .exact(v):
+            return version.major == v.major && version.minor == v.minor && version.patch == v.patch && version.suffix == v.suffix
+        case let .minor(v):
+            return version.major == v.major && version.minor == v.minor
+        }
+    }
+}
+
+public var migrations: [SwiftlyVersionMigration] {
+    [
+        .exact(.init(major: 0, minor: 4, patch: 0, suffix: "dev")),
+        .exact(.init(major: 0, minor: 4, patch: 0)),
+        .minor(.init(major: 1, minor: 0, patch: 0)),
+        .minor(.init(major: 1, minor: 1, patch: 0)),
+        .minor(.init(major: 1, minor: 2, patch: 0)),
+    ]
+}
+
 struct Init: SwiftlyCommand {
     public static let configuration = CommandConfiguration(
         abstract: "Perform swiftly initialization into your user account."
@@ -44,13 +68,7 @@ struct Init: SwiftlyCommand {
 
         var config = try? await Config.load(ctx)
 
-        if var config, !overwrite &&
-            (
-                config.version == SwiftlyVersion(major: 0, minor: 4, patch: 0, suffix: "dev") ||
-                    config.version == SwiftlyVersion(major: 0, minor: 4, patch: 0) ||
-                    (config.version.major == 1 && config.version.minor == 0)
-            )
-        {
+        if var config, !overwrite && !migrations.filter({ $0.matches(config.version) }).isEmpty {
             // This is a simple upgrade from the 0.4.0 pre-releases, or 1.x
 
             // Move our executable over to the correct place

Sources/Swiftly/SelfUpdate.swift

@@ -65,7 +65,8 @@ struct SelfUpdate: SwiftlyCommand {
             fatalError("Unsupported OS")
 #endif
 
-            guard version > SwiftlyCore.version else {
+            // Allow newer or identical versions to help self-update testing of a release
+            guard version >= SwiftlyCore.version else {
                 await ctx.print("Self-update does not support downgrading to an older version or re-installing the current version. Current version is \(SwiftlyCore.version) and requested version is \(version).")
                 return SwiftlyCore.version
             }

Tests/SwiftlyTests/InitTests.swift

@@ -5,6 +5,12 @@ import SystemPackage
 import Testing
 
 @Suite struct InitTests {
+    @Test func migrationsHasCurrentSwiftlyVersion() async throws {
+        // If the current swiftly version isn't in the migration list then it should be added there to
+        // support future self updates.
+        #expect(!migrations.filter { $0.matches(SwiftlyCore.version) }.isEmpty)
+    }
+
     @Test(.testHome(), arguments: ["/bin/bash", "/bin/zsh", "/bin/fish"]) func initFresh(_ shell: String) async throws {
         // GIVEN: a fresh user account without swiftly installed
         try? await fs.remove(atPath: Swiftly.currentPlatform.swiftlyConfigFile(SwiftlyTests.ctx))