Make very basic list devices command

Sources/XcodeSimulatorKit/Commands/ListDevicesCommand.swift

@@ -0,0 +1,14 @@
+import Foundation
+import SPMUtility
+
+struct ListDevicesCommand {
+    func run() throws {
+        let allDevices = try Simctl.listDevices()
+        for (runtime, devices) in allDevices.devices {
+            print("\(runtime):")
+            for device in devices {
+                print(" - \(device.name)")
+            }
+        }
+    }
+}

Sources/XcodeSimulatorKit/Simctl.swift

@@ -7,7 +7,26 @@ struct Simctl {
         case listDevices(errorOutput: String)
     }
 
-    static func listDevices() throws -> Data {
+    struct DeviceList: Codable {
+        var devices: [String: [Device]]
+    }
+
+    struct Device: Codable {
+        enum State: String, Codable {
+            case shutdown = "Shutdown"
+            case booted = "Booted"
+        }
+        var isAvailable: Bool
+        var name: String
+        var udid: String
+        var state: State
+    }
+
+    static func listDevices() throws -> DeviceList {
+        return try parseDeviceList(readListDevices())
+    }
+
+    static func readListDevices() throws -> Data {
         let process = Process(
             args: "xcrun", "simctl", "list", "--json", "devices"
         )
@@ -20,4 +39,9 @@ struct Simctl {
 
         return Data(try result.output.dematerialize())
     }
+
+    static func parseDeviceList(_ data: Data) throws -> DeviceList {
+        let decoder = JSONDecoder()
+        return try decoder.decode(DeviceList.self, from: data)
+    }
 }

Sources/XcodeSimulatorKit/XcodeSimulatorTool.swift

@@ -36,7 +36,7 @@ public class XcodeSimulatorTool {
         case .version:
             print("xcode-simulator-tool version 0.1")
         case .listDevices:
-            print("Listing devices")
+            try ListDevicesCommand().run()
         }
     }
 }

Tests/xcode-simulator-toolTests/SimctlTests.swift

@@ -4,7 +4,7 @@ import XCTest
 
 class SimctlTests: XCTestCase {
     func testListDevices() throws {
-        let jsonData = try Simctl.listDevices()
+        let jsonData: Data = try Simctl.readListDevices()
         let obj = try JSONSerialization.jsonObject(with: jsonData, options: [])
         XCTAssertTrue(obj is [String: Any])
         guard let dict = obj as? [String: Any] else {
@@ -12,5 +12,8 @@ class SimctlTests: XCTestCase {
         }
         XCTAssertEqual(dict.keys.count, 1)
         XCTAssertEqual(dict.keys.first, "devices")
+
+        XCTAssertNoThrow(try Simctl.parseDeviceList(jsonData))
+        _ = try Simctl.parseDeviceList(jsonData)
     }
 }