fix: beta numbers for UUID runtime identifiers

Sources/XcodesKit/Models/Runtimes/Runtimes.swift

@@ -47,6 +47,8 @@ public struct DownloadableRuntime: Codable, Identifiable, Hashable, Sendable {
     public var installState: RuntimeInstallState = .notInstalled
     /// SDK build updates that map to this simulator runtime.
     public var sdkBuildUpdate: [String]?
+    /// The beta seed number supplied by Apple's runtime index.
+    public var seedNumber: Int?
 
     enum CodingKeys: CodingKey {
         case category
@@ -62,15 +64,54 @@ public struct DownloadableRuntime: Codable, Identifiable, Hashable, Sendable {
         case name
         case authentication
         case sdkBuildUpdate
+        case seedNumber
         case architectures
     }
 
-    /// The beta seed number parsed from the runtime identifier, when present.
+    /// The beta seed number supplied by Apple, or inferred from legacy runtime metadata.
     public var betaNumber: Int? {
-        enum Regex { static let shared = try! NSRegularExpression(pattern: "b[0-9]+") }
-        guard var foundString = Regex.shared.firstString(in: identifier) else { return nil }
-        foundString.removeFirst()
-        return Int(foundString)!
+        seedNumber ?? legacyIdentifierBetaNumber ?? nameBetaNumber
+    }
+
+    private var legacyIdentifierBetaNumber: Int? {
+        // Apple's older runtime identifiers encoded the beta seed as a distinct component,
+        // for example `com.apple.dmg.iPhoneSimulatorSDK27_0_b3_1`.
+        //
+        // Newer runtimes can use UUID identifiers. Keep the match delimiter-bound so a
+        // random UUID fragment such as `7cb21db4a45b` is not misread as beta 21.
+        enum Regex {
+            static let shared = try! NSRegularExpression(
+                pattern: "(?:^|[_-])b([0-9]+)(?:[_-]|$)",
+                options: .caseInsensitive
+            )
+        }
+
+        let searchRange = NSRange(identifier.startIndex..., in: identifier)
+        guard
+            let match = Regex.shared.firstMatch(in: identifier, range: searchRange),
+            let betaRange = Range(match.range(at: 1), in: identifier)
+        else { return nil }
+
+        return Int(identifier[betaRange])
+    }
+
+    private var nameBetaNumber: Int? {
+        enum Regex {
+            static let shared = try! NSRegularExpression(
+                pattern: "\\bbeta(?:\\s+([0-9]+))?\\b",
+                options: .caseInsensitive
+            )
+        }
+
+        let searchRange = NSRange(name.startIndex..., in: name)
+        guard let match = Regex.shared.firstMatch(in: name, range: searchRange) else { return nil }
+
+        guard
+            match.range(at: 1).location != NSNotFound,
+            let betaRange = Range(match.range(at: 1), in: name)
+        else { return 1 }
+
+        return Int(name[betaRange])
     }
 
     /// The OS version plus beta suffix when this is a beta runtime.

Sources/XcodesKit/Services/RuntimeListPresentationService.swift

@@ -141,14 +141,18 @@ public struct RuntimeListPresentationService: Sendable {
 }
 
 public extension DownloadableRuntimesResponse {
-    /// Returns downloadable runtimes enriched with SDK build update mappings.
+    /// Returns downloadable runtimes enriched with SDK build and beta seed mappings.
     func downloadablesWithSDKBuildUpdates() -> [DownloadableRuntime] {
         downloadables.map { runtime in
             var updatedRuntime = runtime
             let mappings = sdkToSimulatorMappings.filter {
                 $0.simulatorBuildUpdate == runtime.simulatorVersion.buildUpdate
             }
             updatedRuntime.sdkBuildUpdate = mappings.map(\.sdkBuildUpdate)
+            updatedRuntime.seedNumber = sdkToSeedMappings.first {
+                $0.buildUpdate == runtime.simulatorVersion.buildUpdate &&
+                $0.platform == runtime.platform
+            }?.seedNumber
             return updatedRuntime
         }
     }

Tests/XcodesKitTests/DownloadableRuntimeBetaNumberTests.swift

@@ -0,0 +1,94 @@
+import XCTest
+@testable import XcodesKit
+
+final class DownloadableRuntimeBetaNumberTests: XCTestCase {
+    func testUsesSeedMappingForUUIDRuntime() throws {
+        let response = DownloadableRuntimesResponse(
+            sdkToSimulatorMappings: [],
+            sdkToSeedMappings: [
+                SDKToSeedMapping(buildUpdate: "24A5423a", platform: .iOS, seedNumber: 6)
+            ],
+            refreshInterval: 3600,
+            downloadables: [Self.runtime()],
+            version: "2"
+        )
+
+        let runtime = try XCTUnwrap(response.downloadablesWithSDKBuildUpdates().first)
+
+        XCTAssertEqual(runtime.betaNumber, 6)
+        XCTAssertEqual(runtime.completeVersion, "27.0-beta6")
+        XCTAssertEqual(runtime.visibleIdentifier, "iOS 27.0-beta6")
+    }
+
+    func testUUIDRuntimeFallsBackToNameWithoutMatchingSeedData() {
+        let runtime = Self.runtime()
+
+        XCTAssertEqual(runtime.betaNumber, 6)
+        XCTAssertNotEqual(runtime.betaNumber, 21)
+    }
+
+    func testStableUUIDContainingBFollowedByDigitsIsNotABeta() {
+        let runtime = Self.runtime(name: "iOS 27.0 Simulator Runtime")
+
+        XCTAssertNil(runtime.betaNumber)
+        XCTAssertEqual(runtime.visibleIdentifier, "iOS 27.0")
+    }
+
+    func testLegacyStructuredIdentifierStillProvidesBetaNumber() {
+        let runtime = Self.runtime(
+            identifier: "com.apple.dmg.iPhoneSimulatorSDK27_0_b3_1",
+            name: "iOS 27.0 Simulator Runtime"
+        )
+
+        XCTAssertEqual(runtime.betaNumber, 3)
+    }
+
+    func testUnnumberedBetaNameRepresentsFirstBeta() {
+        let runtime = Self.runtime(
+            identifier: "com.apple.dmg.iPhoneSimulatorSDK27_0_b1",
+            name: "iOS 27.0 beta Simulator Runtime"
+        )
+
+        XCTAssertEqual(runtime.betaNumber, 1)
+    }
+
+    func testSeedNumberSurvivesCacheCodingRoundTrip() throws {
+        var runtime = Self.runtime()
+        runtime.seedNumber = 6
+
+        let data = try JSONEncoder().encode([runtime])
+        let decodedRuntime = try XCTUnwrap(JSONDecoder().decode([DownloadableRuntime].self, from: data).first)
+
+        XCTAssertEqual(decodedRuntime.seedNumber, 6)
+        XCTAssertEqual(decodedRuntime.betaNumber, 6)
+    }
+
+    func testCacheWithoutSeedNumberStillDecodesAndUsesMetadataFallback() throws {
+        let data = try JSONEncoder().encode([Self.runtime()])
+        let decodedRuntime = try XCTUnwrap(JSONDecoder().decode([DownloadableRuntime].self, from: data).first)
+
+        XCTAssertNil(decodedRuntime.seedNumber)
+        XCTAssertEqual(decodedRuntime.betaNumber, 6)
+    }
+
+    private static func runtime(
+        identifier: String = "0218a56d-df74-59c7-a193-7cb21db4a45b",
+        name: String = "iOS 27.0 beta 6 Simulator Runtime"
+    ) -> DownloadableRuntime {
+        DownloadableRuntime(
+            category: .simulator,
+            simulatorVersion: .init(buildUpdate: "24A5423a", version: "27.0"),
+            source: nil,
+            architectures: [.arm64],
+            dictionaryVersion: 2,
+            contentType: .cryptexDiskImage,
+            platform: .iOS,
+            identifier: identifier,
+            version: "27.0.0.6",
+            fileSize: 7_986_041_344,
+            hostRequirements: nil,
+            name: name,
+            authentication: DownloadableRuntime.Authentication.none
+        )
+    }
+}

Tests/XcodesKitTests/RuntimeListStoreTests.swift

@@ -20,7 +20,7 @@ final class RuntimeListStoreTests: XCTestCase {
         XCTAssertEqual(store.downloadableRuntimes, [runtime])
     }
 
-    func testUpdateFetchesAddsSDKBuildUpdatesAndSavesRuntimes() async throws {
+    func testUpdateAddsRuntimeMappingsAndSavesRuntimes() async throws {
         let runtime = Self.downloadableRuntime(buildUpdate: "20A360")
         let response = Self.downloadableResponse(
             downloadables: [runtime],
@@ -31,6 +31,13 @@ final class RuntimeListStoreTests: XCTestCase {
                     sdkIdentifier: "com.apple.platform.iphonesimulator",
                     downloadableIdentifiers: nil
                 )
+            ],
+            sdkToSeedMappings: [
+                SDKToSeedMapping(
+                    buildUpdate: "20A360",
+                    platform: .iOS,
+                    seedNumber: 2
+                )
             ]
         )
         let savedRuntimes = RuntimeCacheSaveRecorder()
@@ -47,6 +54,7 @@ final class RuntimeListStoreTests: XCTestCase {
         let runtimes = try await store.updateDownloadableRuntimes()
 
         XCTAssertEqual(runtimes.map(\.sdkBuildUpdate), [["20A361"]])
+        XCTAssertEqual(runtimes.map(\.seedNumber), [2])
         XCTAssertEqual(store.downloadableRuntimes, runtimes)
         XCTAssertEqual(savedRuntimes.value, runtimes)
     }
@@ -71,11 +79,12 @@ final class RuntimeListStoreTests: XCTestCase {
 
     private static func downloadableResponse(
         downloadables: [DownloadableRuntime],
-        sdkToSimulatorMappings: [SDKToSimulatorMapping] = []
+        sdkToSimulatorMappings: [SDKToSimulatorMapping] = [],
+        sdkToSeedMappings: [SDKToSeedMapping] = []
     ) -> DownloadableRuntimesResponse {
         DownloadableRuntimesResponse(
             sdkToSimulatorMappings: sdkToSimulatorMappings,
-            sdkToSeedMappings: [],
+            sdkToSeedMappings: sdkToSeedMappings,
             refreshInterval: 0,
             downloadables: downloadables,
             version: "1"