Revert "[flutter_tools] avoid creating Android Devices if AndroidSDK cannot be...

Revert "[flutter_tools] avoid creating Android Devices if AndroidSDK cannot be found (#64524)" (#64602)

This reverts commit 47596c62.

packages/flutter_tools/lib/src/android/android_device.dart

@@ -255,7 +255,7 @@ class AndroidDevice extends Device {
   AndroidDevicePortForwarder _portForwarder;
 
   List<String> adbCommandForDevice(List<String> args) {
-    return <String>[_androidSdk.adbPath, '-s', id, ...args];
+    return <String>[getAdbPath(_androidSdk), '-s', id, ...args];
   }
 
   String runAdbCheckedSync(
@@ -318,13 +318,13 @@ class AndroidDevice extends Device {
 
     try {
       final RunResult adbVersion = await _processUtils.run(
-        <String>[_androidSdk.adbPath, 'version'],
+        <String>[getAdbPath(_androidSdk), 'version'],
         throwOnError: true,
       );
       if (_isValidAdbVersion(adbVersion.stdout)) {
         return true;
       }
-      _logger.printError('The ADB at "${_androidSdk.adbPath}" is too old; please install version 1.0.39 or later.');
+      _logger.printError('The ADB at "${getAdbPath(_androidSdk)}" is too old; please install version 1.0.39 or later.');
     } on Exception catch (error, trace) {
       _logger.printError('Error running ADB: $error', stackTrace: trace);
     }
@@ -339,7 +339,7 @@ class AndroidDevice extends Device {
       //   adb server is out of date.  killing..
       //   * daemon started successfully *
       await _processUtils.run(
-        <String>[_androidSdk.adbPath, 'start-server'],
+        <String>[getAdbPath(_androidSdk), 'start-server'],
         throwOnError: true,
       );
 

packages/flutter_tools/lib/src/android/android_device_discovery.dart

@@ -55,13 +55,14 @@ class AndroidDevices extends PollingDeviceDiscovery {
 
   @override
   Future<List<Device>> pollingGetDevices({ Duration timeout }) async {
-    if (_androidSdk == null) {
+    final String adbPath = getAdbPath(_androidSdk);
+    if (adbPath == null) {
       return <AndroidDevice>[];
     }
     String text;
     try {
       text = (await _processUtils.run(
-        <String>[_androidSdk.adbPath, 'devices', '-l'],
+        <String>[adbPath, 'devices', '-l'],
         throwOnError: true,
       )).stdout.trim();
     } on ArgumentError catch (exception) {
@@ -87,11 +88,12 @@ class AndroidDevices extends PollingDeviceDiscovery {
 
   @override
   Future<List<String>> getDiagnostics() async {
-    if (_androidSdk.adbPath == null) {
+    final String adbPath = getAdbPath(_androidSdk);
+    if (adbPath == null) {
       return <String>[];
     }
 
-    final RunResult result = await _processUtils.run(<String>[_androidSdk.adbPath, 'devices', '-l']);
+    final RunResult result = await _processUtils.run(<String>[adbPath, 'devices', '-l']);
     if (result.exitCode != 0) {
       return <String>[];
     } else {

packages/flutter_tools/lib/src/android/android_sdk.dart

@@ -22,6 +22,20 @@ const String kAndroidSdkRoot = 'ANDROID_SDK_ROOT';
 final RegExp _numberedAndroidPlatformRe = RegExp(r'^android-([0-9]+)$');
 final RegExp _sdkVersionRe = RegExp(r'^ro.build.version.sdk=([0-9]+)$');
 
+/// Locate ADB. Prefer to use one from an Android SDK, if we can locate that.
+/// This should be used over accessing androidSdk.adbPath directly because it
+/// will work for those users who have Android Platform Tools installed but
+/// not the full SDK.
+String getAdbPath(AndroidSdk existingSdk) {
+  if (existingSdk?.adbPath != null) {
+    return existingSdk.adbPath;
+  }
+  if (existingSdk?.latestVersion == null) {
+    return globals.os.which('adb')?.path;
+  }
+  return existingSdk?.adbPath;
+}
+
 // Android SDK layout:
 
 // $ANDROID_SDK_ROOT/platform-tools/adb

packages/flutter_tools/lib/src/android/android_workflow.dart

@@ -58,13 +58,13 @@ class AndroidWorkflow implements Workflow {
   bool get appliesToHostPlatform => _featureFlags.isAndroidEnabled;
 
   @override
-  bool get canListDevices => _androidSdk != null && _androidSdk.adbPath != null;
+  bool get canListDevices => getAdbPath(_androidSdk) != null;
 
   @override
   bool get canLaunchDevices => _androidSdk != null && _androidSdk.validateSdkWellFormed().isEmpty;
 
   @override
-  bool get canListEmulators => _androidSdk != null && _androidSdk.emulatorPath != null;
+  bool get canListEmulators => _androidSdk.emulatorPath != null;
 }
 
 class AndroidValidator extends DoctorValidator {

packages/flutter_tools/test/general.shard/android/android_workflow_test.dart

@@ -22,7 +22,6 @@ import 'package:process/process.dart';
 import '../../src/common.dart';
 import '../../src/context.dart';
 import '../../src/mocks.dart' show MockAndroidSdk, MockProcess, MockProcessManager, MockStdio;
-import '../../src/testbed.dart';
 
 class MockAndroidSdkVersion extends Mock implements AndroidSdkVersion {}
 class MockOperatingSystemUtils extends Mock implements OperatingSystemUtils {}
@@ -57,17 +56,6 @@ void main() {
     return (List<String> command) => MockProcess(stdout: stdoutStream);
   }
 
-  testWithoutContext('AndroidWorkflow handles a null AndroidSDK', () {
-    final AndroidWorkflow androidWorkflow = AndroidWorkflow(
-      featureFlags: TestFeatureFlags(),
-      androidSdk: null,
-    );
-
-    expect(androidWorkflow.canLaunchDevices, false);
-    expect(androidWorkflow.canListDevices, false);
-    expect(androidWorkflow.canListEmulators, false);
-  });
-
   testUsingContext('licensesAccepted returns LicensesAccepted.unknown if cannot find sdkmanager', () async {
     processManager.canRunSucceeds = false;
     when(sdk.sdkManagerPath).thenReturn('/foo/bar/sdkmanager');