[flutter_tools] support multiple fuchsia devices (#55780)

Fixes #55765

We are currently only returning the first device from dev-finder, instead we need to look at the whole list.

packages/flutter_tools/lib/src/device.dart

diff --git a/packages/flutter_tools/lib/src/device.dart b/packages/flutter_tools/lib/src/device.dart
index e7df4b3..61d46ff 100644
--- a/packages/flutter_tools/lib/src/device.dart
+++ b/packages/flutter_tools/lib/src/device.dart
@@ -19,6 +19,8 @@
 import 'build_info.dart';
 import 'features.dart';
 import 'fuchsia/fuchsia_device.dart';
+import 'fuchsia/fuchsia_sdk.dart';
+import 'fuchsia/fuchsia_workflow.dart';
 import 'globals.dart' as globals;
 import 'ios/devices.dart';
 import 'ios/simulators.dart';
@@ -82,7 +84,12 @@
       iosWorkflow: globals.iosWorkflow,
     ),
     IOSSimulators(iosSimulatorUtils: globals.iosSimulatorUtils),
-    FuchsiaDevices(),
+    FuchsiaDevices(
+      fuchsiaSdk: fuchsiaSdk,
+      logger: globals.logger,
+      fuchsiaWorkflow: fuchsiaWorkflow,
+      platform: globals.platform,
+    ),
     FlutterTesterDevices(),
     MacOSDevices(),
     LinuxDevices(

packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart

diff --git a/packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart b/packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart
index 0ec719a..9cee2f6 100644
--- a/packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart
+++ b/packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart
@@ -5,6 +5,7 @@
 import 'dart:async';
 
 import 'package:meta/meta.dart';
+import 'package:platform/platform.dart';
 import 'package:vm_service/vm_service.dart' as vm_service;
 
 import '../application_package.dart';
@@ -136,56 +137,75 @@
   }
 }
 
+/// Device discovery for Fuchsia devices.
 class FuchsiaDevices extends PollingDeviceDiscovery {
-  FuchsiaDevices() : super('Fuchsia devices');
+  FuchsiaDevices({
+    @required Platform platform,
+    @required FuchsiaWorkflow fuchsiaWorkflow,
+    @required FuchsiaSdk fuchsiaSdk,
+    @required Logger logger,
+  }) : _platform = platform,
+       _fuchsiaWorkflow = fuchsiaWorkflow,
+       _fuchsiaSdk = fuchsiaSdk,
+       _logger = logger,
+       super('Fuchsia devices');
+
+  final Platform _platform;
+  final FuchsiaWorkflow _fuchsiaWorkflow;
+  final FuchsiaSdk _fuchsiaSdk;
+  final Logger _logger;
 
   @override
-  bool get supportsPlatform => isFuchsiaSupportedPlatform();
+  bool get supportsPlatform => isFuchsiaSupportedPlatform(_platform);
 
   @override
-  bool get canListAnything => fuchsiaWorkflow.canListDevices;
+  bool get canListAnything => _fuchsiaWorkflow.canListDevices;
 
   @override
   Future<List<Device>> pollingGetDevices({ Duration timeout }) async {
-    if (!fuchsiaWorkflow.canListDevices) {
+    if (!_fuchsiaWorkflow.canListDevices) {
       return <Device>[];
     }
-    final String text = await fuchsiaSdk.listDevices(timeout: timeout);
+    final List<String> text = (await _fuchsiaSdk.listDevices(timeout: timeout))
+      ?.split('\n');
     if (text == null || text.isEmpty) {
       return <Device>[];
     }
-    final List<FuchsiaDevice> devices = await parseListDevices(text);
+    final List<FuchsiaDevice> devices = <FuchsiaDevice>[];
+    for (final String line in text) {
+      final FuchsiaDevice device = await _parseDevice(line);
+      if (device == null) {
+        continue;
+      }
+      devices.add(device);
+    }
     return devices;
   }
 
   @override
   Future<List<String>> getDiagnostics() async => const <String>[];
-}
 
-@visibleForTesting
-Future<List<FuchsiaDevice>> parseListDevices(String text) async {
-  final List<FuchsiaDevice> devices = <FuchsiaDevice>[];
-  for (final String rawLine in text.trim().split('\n')) {
-    final String line = rawLine.trim();
+  Future<FuchsiaDevice> _parseDevice(String text) async {
+    final String line = text.trim();
     // ['ip', 'device name']
     final List<String> words = line.split(' ');
     if (words.length < 2) {
-      continue;
+      return null;
     }
     final String name = words[1];
-    final String resolvedHost = await fuchsiaSdk.fuchsiaDevFinder.resolve(
+    final String resolvedHost = await _fuchsiaSdk.fuchsiaDevFinder.resolve(
       name,
       local: false,
     );
     if (resolvedHost == null) {
-      globals.printError('Failed to resolve host for Fuchsia device `$name`');
-      continue;
+      _logger.printError('Failed to resolve host for Fuchsia device `$name`');
+      return null;
     }
-    devices.add(FuchsiaDevice(resolvedHost, name: name));
+    return FuchsiaDevice(resolvedHost, name: name);
   }
-  return devices;
 }
 
+
 class FuchsiaDevice extends Device {
   FuchsiaDevice(String id, {this.name}) : super(
       id,
@@ -451,7 +471,7 @@
   }
 
   @override
-  bool get supportsScreenshot => isFuchsiaSupportedPlatform();
+  bool get supportsScreenshot => isFuchsiaSupportedPlatform(globals.platform);
 
   @override
   Future<void> takeScreenshot(File outputFile) async {

packages/flutter_tools/lib/src/fuchsia/fuchsia_sdk.dart

diff --git a/packages/flutter_tools/lib/src/fuchsia/fuchsia_sdk.dart b/packages/flutter_tools/lib/src/fuchsia/fuchsia_sdk.dart
index f86bbd0..16bc964 100644
--- a/packages/flutter_tools/lib/src/fuchsia/fuchsia_sdk.dart
+++ b/packages/flutter_tools/lib/src/fuchsia/fuchsia_sdk.dart
@@ -4,6 +4,8 @@
 
 import 'dart:async';
 
+import 'package:platform/platform.dart';
+
 import '../base/context.dart';
 import '../base/file_system.dart';
 import '../base/io.dart';
@@ -18,8 +20,8 @@
 FuchsiaSdk get fuchsiaSdk => context.get<FuchsiaSdk>();
 
 /// Returns [true] if the current platform supports Fuchsia targets.
-bool isFuchsiaSupportedPlatform() {
-  return globals.platform.isLinux || globals.platform.isMacOS;
+bool isFuchsiaSupportedPlatform(Platform platform) {
+  return platform.isLinux || platform.isMacOS;
 }
 
 /// The Fuchsia SDK shell commands.
@@ -45,6 +47,8 @@
   FuchsiaKernelCompiler get fuchsiaKernelCompiler =>
       _fuchsiaKernelCompiler ??= FuchsiaKernelCompiler();
 
+  /// Returns any attached devices is a newline-denominated String.
+  ///
   /// Example output:
   ///    $ device-finder list -full
   ///    > 192.168.42.56 paper-pulp-bush-angel
@@ -57,7 +61,7 @@
     if (devices == null) {
       return null;
     }
-    return devices.isNotEmpty ? devices[0] : null;
+    return devices.isNotEmpty ? devices.join('\n') : null;
   }
 
   /// Returns the fuchsia system logs for an attached device where
@@ -116,7 +120,7 @@
   /// FUCHSIA_SSH_CONFIG) to find the ssh configuration needed to talk to
   /// a device.
   factory FuchsiaArtifacts.find() {
-    if (!isFuchsiaSupportedPlatform()) {
+    if (!isFuchsiaSupportedPlatform(globals.platform)) {
       // Don't try to find the artifacts on platforms that are not supported.
       return FuchsiaArtifacts();
     }