Don't fail when no Xcode is selected

Sources/XcodesKit/Environment.swift

@@ -94,6 +94,17 @@ public struct Shell: Sendable {
     }
 
     public var xcodeSelectPrintPath = Shell.shared.xcodeSelectPrintPath
+    /// Returns the path printed by `xcode-select -p`, or `nil` if no developer directory is selected.
+    ///
+    /// `xcode-select -p` fails when no developer directory is selected,
+    /// e.g. on a Mac that doesn't have Xcode or the Command Line Tools installed yet.
+    public func selectedXcodePath() async throws -> String? {
+        do {
+            return try await xcodeSelectPrintPath().out
+        } catch is ProcessExecutionError {
+            return nil
+        }
+    }
 
     public var xcodeSelectSwitch = Shell.shared.xcodeSelectSwitch
     public var isRoot: @Sendable () -> Bool = { NSUserName() == "root" }

Sources/XcodesKit/XcodeInstaller.swift

@@ -498,7 +498,7 @@ public final class XcodeInstaller: Sendable {
     }
 
     public func printAvailableXcodes(_ xcodes: [Xcode], installed installedXcodes: [InstalledXcode], dataSource: DataSource = .xcodeReleases, architectures: [ArchitectureFilter] = []) async throws {
-        let output = try await Current.shell.xcodeSelectPrintPath()
+        let selectedXcodePath = try await Current.shell.selectedXcodePath()
         let machineArchitecture = Current.shell.machineArchitecture()
         let effectiveArchitectures = architectures.isEmpty
             ? [ArchitectureFilter].defaultForMachine(machineHardwareName: machineArchitecture)
@@ -508,7 +508,7 @@ public final class XcodeInstaller: Sendable {
             .availableRows(
                 availableXcodes: xcodes,
                 installedXcodes: installedXcodes,
-                selectedXcodePath: output.out,
+                selectedXcodePath: selectedXcodePath,
                 dataSource: dataSource,
                 architectures: effectiveArchitectures
             )
@@ -530,12 +530,12 @@ public final class XcodeInstaller: Sendable {
     }
 
     public func printInstalledXcodes(directory: Path) async throws {
-        let pathOutput = try await Current.shell.xcodeSelectPrintPath()
+        let selectedXcodePath = try await Current.shell.selectedXcodePath()
         let selectedString = "(Selected)"
         let presentationService = XcodeListPresentationService()
         let rows = presentationService.installedRows(
             installedXcodes: Current.files.installedXcodes(directory),
-            selectedXcodePath: pathOutput.out
+            selectedXcodePath: selectedXcodePath
         )
 
         for line in presentationService.installedLines(rows: rows, interactive: Current.shell.isatty(), selectedMarker: selectedString) {

Sources/XcodesKit/XcodeSelect.swift

@@ -5,11 +5,11 @@ import Rainbow
 import XcodesKit
 
 public func selectXcodeAsync(shouldPrint: Bool, pathOrVersion: String, directory: Path, fallbackToInteractive: Bool = true) async throws {
-    let output = try await Current.shell.xcodeSelectPrintPath()
+    let selectedXcodePath = try await Current.shell.selectedXcodePath()
 
     if shouldPrint {
-        if output.out.isEmpty == false {
-            Current.logging.log(output.out)
+        if let selectedXcodePath, selectedXcodePath.isEmpty == false {
+            Current.logging.log(selectedXcodePath)
         } else {
             Current.logging.log("No selected Xcode")
         }
@@ -26,7 +26,7 @@ public func selectXcodeAsync(shouldPrint: Bool, pathOrVersion: String, directory
     switch selectionService.request(
         pathOrVersion: pathOrVersion,
         installedXcodes: installedXcodes,
-        selectedXcodePath: output.out
+        selectedXcodePath: selectedXcodePath ?? ""
     ) {
     case let .alreadySelectedVersion(version):
         Current.logging.log("Xcode \(version) is already selected".green)
@@ -37,18 +37,19 @@ public func selectXcodeAsync(shouldPrint: Bool, pathOrVersion: String, directory
         Current.logging.log("Selected \(selectedOutput.out)".green)
         Current.shell.exit(0)
         return
-    case .alreadySelectedPath:
+    case .alreadySelectedPath where selectedXcodePath != nil:
         Current.logging.log("Xcode at path \(pathOrVersion) is already selected".green)
         Current.shell.exit(0)
         return
-    case let .selectPath(pathToSelect):
+    // With no Xcode selected, an empty path comes back as `.alreadySelectedPath`, so handle it like `.selectPath`
+    case let .alreadySelectedPath(pathToSelect), let .selectPath(pathToSelect):
         do {
             let selectedOutput = try await selectXcodeAtPathAsync(pathToSelect)
             Current.logging.log("Selected \(selectedOutput.out)".green)
             Current.shell.exit(0)
         } catch {
             guard fallbackToInteractive else { throw error }
-            let selectedOutput = try await selectXcodeInteractivelyAsync(currentPath: output.out, directory: directory)
+            let selectedOutput = try await selectXcodeInteractivelyAsync(currentPath: selectedXcodePath ?? "", directory: directory)
             Current.logging.log("Selected \(selectedOutput.out)".green)
             Current.shell.exit(0)
         }

Tests/XcodesKitTests/XcodesKitTests.swift

@@ -16,6 +16,12 @@ private func configureRainbowForTest(outputTarget: OutputTarget, enabled: Bool)
 final class XcodesKitTests: XCTestCase {
     static let mockXcode = Xcode(version: Version("0.0.0")!, url: URL(string: "https://apple.com/xcode.xip")!, filename: "mock.xip", releaseDate: nil)
 
+    /// `xcode-select -p` exits with status 2 when no developer directory is selected,
+    /// e.g. on a Mac that doesn't have Xcode or the Command Line Tools installed yet.
+    static var noSelectedXcodeError: ProcessExecutionError {
+        ProcessExecutionError(process: Process(), terminationStatus: 2, standardOutput: nil, standardError: nil)
+    }
+
     var xcodeList: XcodeList!
     var xcodeInstaller: XcodeInstaller!
     var sessionService: AppleSessionService!
@@ -1033,6 +1039,21 @@ final class XcodesKitTests: XCTestCase {
         XCTAssertFalse(log.value.contains("Options:"))
     }
 
+    func test_PrintAvailableXcodes_WithNoSelectedXcode_PrintsXcodes() async throws {
+        let log = LockedBox("")
+        XcodesCLIKit.Current.logging.log = { log.append($0 + "\n") }
+        Current.shell.xcodeSelectPrintPath = { throw Self.noSelectedXcodeError }
+
+        try await xcodeInstaller.printAvailableXcodes([Self.mockXcode], installed: [InstalledXcode(path: Path("/Applications/Xcode-0.0.0.app")!)!])
+
+        XCTAssertEqual(log.value, """
+        0.0 (ABC123) (Installed)
+
+        Showing Xcodes for this Mac by default: Apple Silicon (arm64). Switch with `--architecture arm64`, `--architecture x86_64`, `--architecture appleSilicon`, or `--architecture universal`.
+
+        """)
+    }
+
     func test_SelectPrint() async throws {
         let log = LockedBox("")
         XcodesCLIKit.Current.logging.log = { log.append($0 + "\n") }
@@ -1052,6 +1073,24 @@ final class XcodesKitTests: XCTestCase {
         """)
     }
 
+    func test_SelectPrint_WithNoSelectedXcode() async throws {
+        let log = LockedBox("")
+        XcodesCLIKit.Current.logging.log = { log.append($0 + "\n") }
+
+        Current.files.installedXcodes = { _ in
+            [InstalledXcode(path: Path("/Applications/Xcode-0.0.0.app")!)!]
+        }
+
+        Current.shell.xcodeSelectPrintPath = { throw Self.noSelectedXcodeError }
+
+        try await selectXcodeAsync(shouldPrint: true, pathOrVersion: "", directory: Path.root.join("Applications"))
+
+        XCTAssertEqual(log.value, """
+        No selected Xcode
+
+        """)
+    }
+
     func test_SelectPath() async throws {
         let log = LockedBox("")
         XcodesCLIKit.Current.logging.log = { log.append($0 + "\n") }
@@ -1199,6 +1238,70 @@ final class XcodesKitTests: XCTestCase {
         """)
     }
 
+    func test_SelectInteractively_WithNoSelectedXcode() async throws {
+        let log = LockedBox("")
+        XcodesCLIKit.Current.logging.log = { log.append($0 + "\n") }
+
+        // There are installed Xcodes
+        Current.files.installedXcodes = { _ in
+            [InstalledXcode(path: Path("/Applications/Xcode-0.0.0.app")!)!,
+             InstalledXcode(path: Path("/Applications/Xcode-2.0.1.app")!)!]
+        }
+        Current.files.contentsAtPath = { path in
+            if path == "/Applications/Xcode-0.0.0.app/Contents/Info.plist" {
+                let url = Bundle.module.url(forResource: "Stub-0.0.0.Info", withExtension: "plist", subdirectory: "Fixtures")!
+                return try? Data(contentsOf: url)
+            }
+            else if path == "/Applications/Xcode-2.0.1.app/Contents/Info.plist" {
+                let url = Bundle.module.url(forResource: "Stub-2.0.1.Info", withExtension: "plist", subdirectory: "Fixtures")!
+                return try? Data(contentsOf: url)
+            }
+            else if path.contains("version.plist") {
+                let url = Bundle.module.url(forResource: "Stub.version", withExtension: "plist", subdirectory: "Fixtures")!
+                return try? Data(contentsOf: url)
+            }
+            else {
+                return nil
+            }
+        }
+        Current.files.fileExistsAtPath = { path in
+            if path == "" {
+                return false
+            }
+            return true
+        }
+        // No Xcode is selected until one is switched to
+        let xcodeSelectPrintPathCallCount = LockedBox(0)
+        Current.shell.xcodeSelectPrintPath = {
+            if xcodeSelectPrintPathCallCount.increment() == 1 {
+                throw Self.noSelectedXcodeError
+            }
+            else {
+                return (status: 0, out: "/Applications/Xcode-2.0.1.app/Contents/Developer", err: "")
+            }
+        }
+        // User enters an index
+        XcodesCLIKit.Current.shell.readLine = { prompt in
+            XcodesCLIKit.Current.logging.log(prompt)
+            return "2"
+        }
+        // It successfully switches
+        Current.shell.xcodeSelectSwitch = { _, _ in
+            (status: 0, out: "", err: "")
+        }
+
+        try await selectXcodeAsync(shouldPrint: false, pathOrVersion: "", directory: Path.root.join("Applications"))
+
+        XCTAssertEqual(log.value, """
+        Available Xcode versions:
+        1) 0.0 (ABC123)
+        2) 2.0.1 (ABC123)
+        Enter the number of the Xcode to select: 
+        Selected /Applications/Xcode-2.0.1.app/Contents/Developer
+
+        """)
+    }
+
     func test_SelectUsingXcodeVersionFile() async throws {
         let log = LockedBox("")
         XcodesCLIKit.Current.logging.log = { log.append($0 + "\n") }
@@ -1367,6 +1470,32 @@ final class XcodesKitTests: XCTestCase {
         )
     }
 
+    func test_Installed_WithNoSelectedXcode() async throws {
+        let log = LockedBox("")
+        XcodesCLIKit.Current.logging.log = { log.append($0 + "\n") }
+
+        // There is an installed Xcode
+        Current.files.installedXcodes = { _ in
+            [InstalledXcode(path: Path("/Applications/Xcode-0.0.0.app")!)!]
+        }
+
+        // None is selected
+        Current.shell.xcodeSelectPrintPath = { throw Self.noSelectedXcodeError }
+
+        // Standard output is not an interactive terminal
+        Current.shell.isatty = { false }
+
+        try await xcodeInstaller.printInstalledXcodes(directory: Path.root/"Applications")
+
+        XCTAssertEqual(
+            log.value,
+            """
+            0.0 (ABC123)\t/Applications/Xcode-0.0.0.app
+
+            """
+        )
+    }
+
     func test_Installed_WithValidVersion_PrintsXcodePath() async throws {
         let log = LockedBox("")
         XcodesCLIKit.Current.logging.log = { log.append($0 + "\n") }