Quick fix to ignore new iOS 18 runtime downloadables

With introduction if Xcode 16 and iOS 18 simulators, a breaking change
for xcodes was introduced through the simulators API. ("https://devimages-cdn.apple.com/downloads/xcode/simulators/index2.dvtdownloadableindex")

In order to keep current functionality working, I made 2
modifications:
1. Make runtime source optional. This is needed as iOS 18 downloadable
does not have that value.
2. Add support for new `cryptexDiskImage` content type. As iOS 18
downloadable comes with new type of `contentType`, we should parse it
in order to be able to process rest of the response.

In RuntimeInstaller, I've added logic to handle new optional and new
content type be throwing error if those downloadable were to be used.

Test cases and fixtures were also updated to handle these new cases.

Sources/XcodesKit/Models+Runtimes.swift

@@ -11,7 +11,7 @@ struct DownloadableRuntimesResponse: Decodable {
 public struct DownloadableRuntime: Decodable {
     let category: Category
     let simulatorVersion: SimulatorVersion
-    let source: String
+    let source: String?
     let dictionaryVersion: Int
     let contentType: ContentType
     let platform: Platform
@@ -79,6 +79,7 @@ extension DownloadableRuntime {
     enum ContentType: String, Decodable {
         case diskImage = "diskImage"
         case package = "package"
+        case cryptexDiskImage = "cryptexDiskImage"
     }
 
     enum Platform: String, Decodable {

Sources/XcodesKit/RuntimeInstaller.swift

@@ -112,6 +112,8 @@ public class RuntimeInstaller {
                 try await installFromPackage(dmgUrl: dmgUrl, runtime: matchedRuntime)
             case .diskImage:
                 try await installFromImage(dmgUrl: dmgUrl)
+            case .cryptexDiskImage:
+                throw Error.unsupportedCryptexDiskImage
         }
         if shouldDelete {
             Current.logging.log("Deleting Archive")
@@ -183,7 +185,10 @@ public class RuntimeInstaller {
 
     @MainActor
     public func downloadOrUseExistingArchive(runtime: DownloadableRuntime, to destinationDirectory: Path, downloader: Downloader) async throws -> URL {
-        let url = URL(string: runtime.source)!
+        guard let source = runtime.source else {
+            throw Error.missingRuntimeSource(runtime.identifier)
+        }
+        let url = URL(string: source)!
         let destination = destinationDirectory/url.lastPathComponent
         let aria2DownloadMetadataPath = destination.parent/(destination.basename() + ".aria2")
         var aria2DownloadIsIncomplete = false
@@ -226,6 +231,8 @@ extension RuntimeInstaller {
         case unavailableRuntime(String)
         case failedMountingDMG
         case rootNeeded
+        case missingRuntimeSource(String)
+        case unsupportedCryptexDiskImage
 
         public var errorDescription: String? {
             switch self {
@@ -235,6 +242,10 @@ extension RuntimeInstaller {
                     return "Failed to mount image."
                 case .rootNeeded:
                     return "Must be run as root to install the specified runtime"
+                case let .missingRuntimeSource(identifier):
+                    return "Runtime \(identifier) is missing source url."
+                case .unsupportedCryptexDiskImage:
+                    return "Cryptex Disk Image is not yet supported."
             }
         }
     }

Tests/XcodesKitTests/Fixtures/DownloadableRuntimes.plist

@@ -1794,7 +1794,34 @@
                 <key>version</key>
                 <string>1.0.0.1</string>
             </dict>
-	</array>
+            <dict>
+                <key>category</key>
+                <string>simulator</string>
+                <key>contentType</key>
+                <string>cryptexDiskImage</string>
+                <key>dictionaryVersion</key>
+                <integer>2</integer>
+                <key>downloadMethod</key>
+                <string>mobileAsset</string>
+                <key>fileSize</key>
+                <integer>8455760175</integer>
+                <key>identifier</key>
+                <string>com.apple.dmg.iPhoneSimulatorSDK18_0_b1</string>
+                <key>name</key>
+                <string>iOS 18.0 beta Simulator Runtime</string>
+                <key>platform</key>
+                <string>com.apple.platform.iphoneos</string>
+                <key>simulatorVersion</key>
+                <dict>
+                    <key>buildUpdate</key>
+                    <string>22A5282m</string>
+                    <key>version</key>
+                    <string>18.0</string>
+                </dict>
+                <key>version</key>
+                <string>18.0.0.1</string>
+            </dict>
+        </array>
         <key>refreshInterval</key>
         <integer>86400</integer>
         <key>sdkToSeedMappings</key>

Tests/XcodesKitTests/Fixtures/LogOutput-Runtimes.txt

@@ -25,6 +25,7 @@ iOS 16.2
 iOS 16.4
 iOS 17.0-beta1
 iOS 17.0-beta2
+iOS 18.0-beta1
 -- watchOS --
 watchOS 6.0
 watchOS 6.1.1

Tests/XcodesKitTests/RuntimeTests.swift

@@ -80,7 +80,7 @@ final class RuntimeTests: XCTestCase {
     func test_downloadableRuntimes() async throws {
         mockDownloadables()
         let values = try await runtimeList.downloadableRuntimes().downloadables
-        XCTAssertEqual(values.count, 59)
+        XCTAssertEqual(values.count, 60)
     }
 
     func test_downloadableRuntimesNoBetas() async throws {
@@ -171,7 +171,7 @@ final class RuntimeTests: XCTestCase {
         }
 
         let url = try await runtimeInstaller.downloadOrUseExistingArchive(runtime: runtime, to: .xcodesCaches, downloader: .urlSession)
-        let fileName = URL(string: runtime.source)!.lastPathComponent
+        let fileName = URL(string: runtime.source!)!.lastPathComponent
         XCTAssertEqual(url, Path.xcodesCaches.join(fileName).url)
         XCTAssertNil(xcodeDownloadURL)
     }
@@ -185,10 +185,10 @@ final class RuntimeTests: XCTestCase {
             return (Progress(), Promise.value((destination, HTTPURLResponse(url: url.pmkRequest.url!, statusCode: 200, httpVersion: nil, headerFields: nil)!)))
         }
         let runtime = try await runtimeList.downloadableRuntimes().downloadables.first { $0.visibleIdentifier == "iOS 15.5" }!
-        let fileName = URL(string: runtime.source)!.lastPathComponent
+        let fileName = URL(string: runtime.source!)!.lastPathComponent
         let url = try await runtimeInstaller.downloadOrUseExistingArchive(runtime: runtime, to: .xcodesCaches, downloader: .urlSession)
         XCTAssertEqual(url, Path.xcodesCaches.join(fileName).url)
-        XCTAssertEqual(xcodeDownloadURL, URL(string: runtime.source)!)
+        XCTAssertEqual(xcodeDownloadURL, URL(string: runtime.source!)!)
     }
 
     func test_installStepsForPackage() async throws {