Throw exception if instantiating IOSDevice on non-mac os platform (#36288)

packages/flutter_tools/lib/src/ios/devices.dart

@@ -125,14 +125,12 @@ class IOSDevice extends Device {
           ephemeral: true,
       ) {
     if (!platform.isMacOS) {
-      printError('Cannot control iOS devices or simulators. ideviceinstaller and iproxy are not available on your platform.');
-      _installerPath = null;
-      _iproxyPath = null;
+      assert(false, 'Control of iOS devices or simulators only supported on Mac OS.');
       return;
     }
     _installerPath = artifacts.getArtifactPath(
       Artifact.ideviceinstaller,
-      platform: TargetPlatform.ios
+      platform: TargetPlatform.ios,
     ) ?? 'ideviceinstaller'; // TODO(fujino): remove fallback once g3 updated
     _iproxyPath = artifacts.getArtifactPath(
       Artifact.iproxy,
@@ -168,6 +166,9 @@ class IOSDevice extends Device {
   bool get supportsStartPaused => false;
 
   static Future<List<IOSDevice>> getAttachedDevices() async {
+    if (!platform.isMacOS) {
+      throw UnsupportedError('Control of iOS devices or simulators only supported on Mac OS.');
+    }
     if (!iMobileDevice.isInstalled)
       return <IOSDevice>[];
 

packages/flutter_tools/test/general.shard/ios/devices_test.dart

@@ -38,6 +38,30 @@ class MockProcess extends Mock implements Process {}
 void main() {
   final FakePlatform macPlatform = FakePlatform.fromPlatform(const LocalPlatform());
   macPlatform.operatingSystem = 'macos';
+  final FakePlatform linuxPlatform = FakePlatform.fromPlatform(const LocalPlatform());
+  linuxPlatform.operatingSystem = 'linux';
+  final FakePlatform windowsPlatform = FakePlatform.fromPlatform(const LocalPlatform());
+  windowsPlatform.operatingSystem = 'windows';
+
+  group('IOSDevice', () {
+    final List<Platform> unsupportedPlatforms = <Platform>[linuxPlatform, windowsPlatform];
+
+    testUsingContext('successfully instantiates on Mac OS', () {
+      IOSDevice('device-123');
+    }, overrides: <Type, Generator>{
+      Platform: () => macPlatform,
+    });
+
+    for (Platform platform in unsupportedPlatforms) {
+      testUsingContext('throws UnsupportedError exception if instantiated on ${platform.operatingSystem}', () {
+        expect(
+            () { IOSDevice('device-123'); },
+            throwsA(isInstanceOf<AssertionError>())
+        );
+      }, overrides: <Type, Generator>{
+        Platform: () => platform,
+      });
+    }
 
     group('Process calls', () {
       MockIOSApp mockApp;
@@ -126,6 +150,7 @@ void main() {
         ProcessManager: () => mockProcessManager,
       });
     });
+  });
 
   group('getAttachedDevices', () {
     MockIMobileDevice mockIMobileDevice;
@@ -139,6 +164,7 @@ void main() {
       expect(await IOSDevice.getAttachedDevices(), isEmpty);
     }, overrides: <Type, Generator>{
       IMobileDevice: () => mockIMobileDevice,
+      Platform: () => macPlatform,
     });
 
     testUsingContext('returns no devices if none are attached', () async {
@@ -149,8 +175,25 @@ void main() {
       expect(devices, isEmpty);
     }, overrides: <Type, Generator>{
       IMobileDevice: () => mockIMobileDevice,
+      Platform: () => macPlatform,
     });
 
+    final List<Platform> unsupportedPlatforms = <Platform>[linuxPlatform, windowsPlatform];
+    for (Platform platform in unsupportedPlatforms) {
+      testUsingContext('throws Unsupported Operation exception on ${platform.operatingSystem}', () async {
+        when(iMobileDevice.isInstalled).thenReturn(false);
+        when(iMobileDevice.getAvailableDeviceIDs())
+            .thenAnswer((Invocation invocation) => Future<String>.value(''));
+        expect(
+            () async { await IOSDevice.getAttachedDevices(); },
+            throwsA(isInstanceOf<UnsupportedError>()),
+        );
+      }, overrides: <Type, Generator>{
+        IMobileDevice: () => mockIMobileDevice,
+        Platform: () => platform,
+      });
+    }
+
     testUsingContext('returns attached devices', () async {
       when(iMobileDevice.isInstalled).thenReturn(true);
       when(iMobileDevice.getAvailableDeviceIDs())
@@ -174,6 +217,7 @@ f577a7903cc54959be2e34bc4f7f80b7009efcf4
       expect(devices[1].name, 'Puits sans fond');
     }, overrides: <Type, Generator>{
       IMobileDevice: () => mockIMobileDevice,
+      Platform: () => macPlatform,
     });
 
     testUsingContext('returns attached devices and ignores devices that cannot be found by ideviceinfo', () async {
@@ -193,6 +237,7 @@ f577a7903cc54959be2e34bc4f7f80b7009efcf4
       expect(devices[0].name, 'La tele me regarde');
     }, overrides: <Type, Generator>{
       IMobileDevice: () => mockIMobileDevice,
+      Platform: () => macPlatform,
     });
   });
 
@@ -244,8 +289,8 @@ f577a7903cc54959be2e34bc4f7f80b7009efcf4
       expect(lines, <String>['A is for ari', 'I is for ichigo']);
     }, overrides: <Type, Generator>{
       IMobileDevice: () => mockIMobileDevice,
+      Platform: () => macPlatform,
     });
-
     testUsingContext('includes multi-line Flutter logs in the output', () async {
       when(mockIMobileDevice.startLogger('123456')).thenAnswer((Invocation invocation) {
         final Process mockProcess = MockProcess();
@@ -280,9 +325,9 @@ f577a7903cc54959be2e34bc4f7f80b7009efcf4
       expect(device.category, Category.mobile);
     }, overrides: <Type, Generator>{
       IMobileDevice: () => mockIMobileDevice,
+      Platform: () => macPlatform,
     });
   });
-
   testUsingContext('IOSDevice.isSupportedForProject is true on module project', () async {
     fs.file('pubspec.yaml')
       ..createSync()
@@ -298,8 +343,8 @@ flutter:
     expect(IOSDevice('test').isSupportedForProject(flutterProject), true);
   }, overrides: <Type, Generator>{
     FileSystem: () => MemoryFileSystem(),
+    Platform: () => macPlatform,
   });
-
   testUsingContext('IOSDevice.isSupportedForProject is true with editable host app', () async {
     fs.file('pubspec.yaml').createSync();
     fs.file('.packages').createSync();
@@ -309,6 +354,7 @@ flutter:
     expect(IOSDevice('test').isSupportedForProject(flutterProject), true);
   }, overrides: <Type, Generator>{
     FileSystem: () => MemoryFileSystem(),
+    Platform: () => macPlatform,
   });
 
   testUsingContext('IOSDevice.isSupportedForProject is false with no host app and no module', () async {
@@ -319,5 +365,6 @@ flutter:
     expect(IOSDevice('test').isSupportedForProject(flutterProject), false);
   }, overrides: <Type, Generator>{
     FileSystem: () => MemoryFileSystem(),
+    Platform: () => macPlatform,
   });
 }