[ Tool ] Support Powershell v6+ to determine Windows version in flutter doctor (#156476)

Powershell v6+ use the executable name `pwsh.exe` instead of
`powershell.exe`. This change adds support for determining the Windows
version on systems that solely use `pwsh.exe` and don't have
`powershell.exe` on the `PATH`.

Fixes #156189.

---------

Co-authored-by: Andrew Kolos <andrewrkolos@gmail.com>

packages/flutter_tools/lib/src/windows/windows_version_validator.dart

@@ -37,9 +37,22 @@ class WindowsVersionValidator extends DoctorValidator {
   final ProcessLister _processLister;
 
   Future<ValidationResult> _topazScan() async {
+      if (!_processLister.canRunPowershell()) {
+        return const ValidationResult(
+          ValidationType.missing,
+          <ValidationMessage>[
+            ValidationMessage.hint('Failed to find ${ProcessLister.powershell} or ${ProcessLister.pwsh} on PATH'),
+          ],
+        );
+      }
       final ProcessResult getProcessesResult = await _processLister.getProcessesWithPath();
       if (getProcessesResult.exitCode != 0) {
-        return const ValidationResult(ValidationType.missing, <ValidationMessage>[ValidationMessage.hint('Get-Process failed to complete')]);
+        return const ValidationResult(
+          ValidationType.missing,
+          <ValidationMessage>[
+            ValidationMessage.hint('Get-Process failed to complete'),
+          ],
+        );
       }
       final RegExp topazRegex = RegExp(kCoreProcessPattern, caseSensitive: false,  multiLine: true);
       final String processes = getProcessesResult.stdout as String;
@@ -106,8 +119,22 @@ class ProcessLister {
 
   final ProcessManager processManager;
 
+  static const String powershell = 'powershell';
+  static const String pwsh = 'pwsh';
+
+  bool canRunPowershell() {
+    return processManager.canRun(powershell) || processManager.canRun(pwsh);
+  }
+
   Future<ProcessResult> getProcessesWithPath() async {
     const String argument = 'Get-Process | Format-List Path';
-    return processManager.run(<String>['powershell', '-command', argument]);
+    const List<String> psArgs = <String>['-command', argument];
+    if (processManager.canRun(powershell)) {
+      return processManager.run(<String>[powershell, ...psArgs]);
+    }
+    if (processManager.canRun(pwsh)) {
+      return processManager.run(<String>[pwsh, ...psArgs]);
+    }
+    throw StateError('Failed to find $powershell or $pwsh on PATH');
   }
 }

packages/flutter_tools/test/general.shard/windows_version_validator_test.dart

@@ -9,6 +9,7 @@ import 'package:flutter_tools/src/windows/windows_version_validator.dart';
 import 'package:test/fake.dart';
 
 import '../src/common.dart';
+import '../src/context.dart';
 
 /// Fake [_WindowsUtils] to use for testing
 class FakeValidOperatingSystemUtils extends Fake
@@ -21,14 +22,22 @@ class FakeValidOperatingSystemUtils extends Fake
 }
 
 class FakeProcessLister extends Fake implements ProcessLister {
-  FakeProcessLister({required this.result, this.exitCode = 0});
+  FakeProcessLister({
+    required this.result,
+    this.exitCode = 0,
+    this.powershellAvailable = true,
+  });
   final String result;
   final int exitCode;
+  final bool powershellAvailable;
 
   @override
   Future<ProcessResult> getProcessesWithPath() async {
     return ProcessResult(0, exitCode, result, null);
   }
+
+  @override
+  bool canRunPowershell() => powershellAvailable;
 }
 
 FakeProcessLister ofdRunning() {
@@ -43,6 +52,10 @@ FakeProcessLister failure() {
   return FakeProcessLister(result: r'Path: "C:\Program Files\Google\Chrome\Application\chrome.exe', exitCode: 10);
 }
 
+FakeProcessLister powershellUnavailable() {
+  return FakeProcessLister(result: '', powershellAvailable: false);
+}
+
 /// The expected validation result object for
 /// a passing windows version test
 const ValidationResult validWindows10ValidationResult = ValidationResult(
@@ -70,6 +83,15 @@ const ValidationResult ofdFoundRunning = ValidationResult(
   statusInfo: 'Problem detected with Windows installation',
 );
 
+const ValidationResult powershellUnavailableResult = ValidationResult(
+  ValidationType.partial,
+  <ValidationMessage>[
+    ValidationMessage.hint('Failed to find ${ProcessLister.powershell} or ${ProcessLister.pwsh} on PATH'),
+  ],
+  statusInfo: 'Problem detected with Windows installation',
+);
+
+
 const ValidationResult getProcessFailed = ValidationResult(
   ValidationType.partial,
   <ValidationMessage>[
@@ -158,6 +180,18 @@ OS 版本:          10.0.22621 暂缺 Build 22621
     expect(result.messages[0].message, ofdFoundRunning.messages[0].message, reason: 'The ValidationMessage message should be the same');
   });
 
+  testWithoutContext('Reports missing powershell', () async {
+    final WindowsVersionValidator validator =
+        WindowsVersionValidator(
+            operatingSystemUtils: FakeValidOperatingSystemUtils(),
+            processLister: powershellUnavailable());
+    final ValidationResult result = await validator.validate();
+    expect(result.type, powershellUnavailableResult.type, reason: 'The ValidationResult type should be the same (partial)');
+    expect(result.statusInfo, powershellUnavailableResult.statusInfo, reason: 'The ValidationResult statusInfo should be the same');
+    expect(result.messages.length, 1, reason: 'The ValidationResult should have precisely 1 message');
+    expect(result.messages[0].message, powershellUnavailableResult.messages[0].message, reason: 'The ValidationMessage message should be the same');
+  });
+
   testWithoutContext('Reports failure of Get-Process', () async {
     final WindowsVersionValidator validator =
         WindowsVersionValidator(
@@ -169,4 +203,75 @@ OS 版本:          10.0.22621 暂缺 Build 22621
     expect(result.messages.length, 1, reason: 'The ValidationResult should have precisely 1 message');
     expect(result.messages[0].message, getProcessFailed.messages[0].message, reason: 'The ValidationMessage message should be the same');
   });
+
+  testWithoutContext('getProcessesWithPath successfully runs with powershell', () async {
+    final ProcessLister processLister = ProcessLister(
+      FakeProcessManager.list(
+        <FakeCommand>[
+          const FakeCommand(
+            command: <String>[
+              ProcessLister.powershell,
+              '-command',
+              'Get-Process | Format-List Path',
+            ],
+            stdout: ProcessLister.powershell,
+          ),
+        ],
+      )..excludedExecutables.add(ProcessLister.pwsh),
+    );
+
+    try {
+      final ProcessResult result = await processLister.getProcessesWithPath();
+      expect(result.stdout, ProcessLister.powershell);
+    // ignore: avoid_catches_without_on_clauses
+    } catch (e) {
+      fail('Unexpected exception: $e');
+    }
+  });
+
+  testWithoutContext('getProcessesWithPath falls back to pwsh when powershell is not on the path', () async {
+    final ProcessLister processLister = ProcessLister(
+      FakeProcessManager.list(
+        <FakeCommand>[
+          const FakeCommand(
+            command: <String>[
+              ProcessLister.pwsh,
+              '-command',
+              'Get-Process | Format-List Path',
+            ],
+            stdout: ProcessLister.pwsh,
+          ),
+        ],
+      )..excludedExecutables.add(ProcessLister.powershell),
+    );
+
+    try {
+      final ProcessResult result = await processLister.getProcessesWithPath();
+      expect(result.stdout, ProcessLister.pwsh);
+    // ignore: avoid_catches_without_on_clauses
+    } catch (e) {
+      fail('Unexpected exception: $e');
+    }
+  });
+
+  testWithoutContext('getProcessesWithPath throws if both powershell and pwsh are not on PATH', () async {
+    final ProcessLister processLister = ProcessLister(
+      FakeProcessManager.empty()..excludedExecutables.addAll(
+        <String>[
+          ProcessLister.powershell,
+          ProcessLister.pwsh,
+        ],
+      ),
+    );
+
+    try {
+      final ProcessResult result = await processLister.getProcessesWithPath();
+      fail('Should have thrown, but successfully ran ${result.stdout}');
+    } on StateError {
+      // Expected
+    // ignore: avoid_catches_without_on_clauses
+    } catch (e) {
+      fail('Unexpected exception: $e');
+    }
+  });
 }