[flutter_tools] Show linux distribution and kernel release in `flutter doctor` (#81368)

packages/flutter_tools/lib/src/base/os.dart

@@ -35,6 +35,13 @@ abstract class OperatingSystemUtils {
         platform: platform,
         processManager: processManager,
       );
+    } else if (platform.isLinux) {
+      return _LinuxUtils(
+        fileSystem: fileSystem,
+        logger: logger,
+        platform: platform,
+        processManager: processManager,
+      );
     } else {
       return _PosixUtils(
         fileSystem: fileSystem,
@@ -283,6 +290,78 @@ class _PosixUtils extends OperatingSystemUtils {
   }
 }
 
+class _LinuxUtils extends _PosixUtils {
+  _LinuxUtils({
+    required FileSystem fileSystem,
+    required Logger logger,
+    required Platform platform,
+    required ProcessManager processManager,
+  }) : super(
+          fileSystem: fileSystem,
+          logger: logger,
+          platform: platform,
+          processManager: processManager,
+        );
+
+  String? _name;
+
+  @override
+  String get name {
+    if (_name == null) {
+      const String prettyNameKey = 'PRETTY_NAME';
+      // If "/etc/os-release" doesn't exist, fallback to "/usr/lib/os-release".
+      final String osReleasePath = _fileSystem.file('/etc/os-release').existsSync()
+        ? '/etc/os-release'
+        : '/usr/lib/os-release';
+      String prettyName;
+      String kernelRelease;
+      try {
+        final String osRelease = _fileSystem.file(osReleasePath).readAsStringSync();
+        prettyName = _getOsReleaseValueForKey(osRelease, prettyNameKey);
+      } on Exception catch (e) {
+        _logger.printTrace('Failed obtaining PRETTY_NAME for Linux: $e');
+        prettyName = '';
+      }
+      try {
+        // Split the operating system version which should be formatted as
+        // "Linux kernelRelease build", by spaces.
+        final List<String> osVersionSplitted = _platform.operatingSystemVersion.split(' ');
+        if (osVersionSplitted.length < 3) {
+          // The operating system version didn't have the expected format.
+          // Initialize as an empty string.
+          kernelRelease = '';
+        } else {
+          kernelRelease = ' ${osVersionSplitted[1]}';
+        }
+      } on Exception catch (e) {
+        _logger.printTrace('Failed obtaining kernel release for Linux: $e');
+        kernelRelease = '';
+      }
+      _name = '${prettyName.isEmpty ? super.name : prettyName}$kernelRelease';
+    }
+    return _name!;
+  }
+
+  String _getOsReleaseValueForKey(String osRelease, String key) {
+    final List<String> osReleaseSplitted = osRelease.split('\n');
+    for (String entry in osReleaseSplitted) {
+      entry = entry.trim();
+      final List<String> entryKeyValuePair = entry.split('=');
+      if(entryKeyValuePair[0] == key) {
+        final String value =  entryKeyValuePair[1];
+        // Remove quotes from either end of the value if they exist
+        final String quote = value[0];
+        if (quote == '\'' || quote == '"') {
+          return value.substring(0, value.length - 1).substring(1);
+        } else {
+          return value;
+        }
+      }
+    }
+    return '';
+  }
+}
+
 class _MacOSUtils extends _PosixUtils {
   _MacOSUtils({
     required FileSystem fileSystem,

packages/flutter_tools/test/general.shard/base/os_test.dart

@@ -380,6 +380,134 @@ void main() {
           createOSUtils(FakePlatform(operatingSystem: 'macos'));
       expect(utils.name, 'product version build darwin-x64');
     });
+
+    testWithoutContext('Windows name', () async {
+      fakeProcessManager.addCommands(<FakeCommand>[
+        const FakeCommand(
+          command: <String>[
+            'ver',
+          ],
+          stdout: 'version',
+        ),
+      ]);
+
+      final OperatingSystemUtils utils =
+          createOSUtils(FakePlatform(operatingSystem: 'windows'));
+      expect(utils.name, 'version');
+    });
+
+    testWithoutContext('Linux name', () async {
+      const String fakeOsRelease = '''
+      NAME="Name"
+      ID=id
+      ID_LIKE=id_like
+      BUILD_ID=build_id
+      PRETTY_NAME="Pretty Name"
+      ANSI_COLOR="ansi color"
+      HOME_URL="https://home.url/"
+      DOCUMENTATION_URL="https://documentation.url/"
+      SUPPORT_URL="https://support.url/"
+      BUG_REPORT_URL="https://bug.report.url/"
+      LOGO=logo
+      ''';
+      final FileSystem fileSystem = MemoryFileSystem.test();
+      fileSystem.directory('/etc').createSync();
+      fileSystem.file('/etc/os-release').writeAsStringSync(fakeOsRelease);
+
+      final OperatingSystemUtils utils = OperatingSystemUtils(
+        fileSystem: fileSystem,
+        logger: BufferLogger.test(),
+        platform: FakePlatform(
+          operatingSystem: 'linux',
+          operatingSystemVersion: 'Linux 1.2.3-abcd #1 SMP PREEMPT Sat Jan 1 00:00:00 UTC 2000',
+        ),
+        processManager: fakeProcessManager,
+      );
+      expect(utils.name, 'Pretty Name 1.2.3-abcd');
+    });
+
+    testWithoutContext('Linux name reads from "/usr/lib/os-release" if "/etc/os-release" is missing', () async {
+      const String fakeOsRelease = '''
+      NAME="Name"
+      ID=id
+      ID_LIKE=id_like
+      BUILD_ID=build_id
+      PRETTY_NAME="Pretty Name"
+      ANSI_COLOR="ansi color"
+      HOME_URL="https://home.url/"
+      DOCUMENTATION_URL="https://documentation.url/"
+      SUPPORT_URL="https://support.url/"
+      BUG_REPORT_URL="https://bug.report.url/"
+      LOGO=logo
+      ''';
+      final FileSystem fileSystem = MemoryFileSystem.test();
+      fileSystem.directory('/usr/lib').createSync(recursive: true);
+      fileSystem.file('/usr/lib/os-release').writeAsStringSync(fakeOsRelease);
+
+      expect(fileSystem.file('/etc/os-release').existsSync(), false);
+
+      final OperatingSystemUtils utils = OperatingSystemUtils(
+        fileSystem: fileSystem,
+        logger: BufferLogger.test(),
+        platform: FakePlatform(
+          operatingSystem: 'linux',
+          operatingSystemVersion: 'Linux 1.2.3-abcd #1 SMP PREEMPT Sat Jan 1 00:00:00 UTC 2000',
+        ),
+        processManager: fakeProcessManager,
+      );
+      expect(utils.name, 'Pretty Name 1.2.3-abcd');
+    });
+
+    testWithoutContext('Linux name when reading "/etc/os-release" fails', () async {
+      final FileExceptionHandler handler = FileExceptionHandler();
+      final FileSystem fileSystem = MemoryFileSystem.test(opHandle: handler.opHandle);
+
+      fileSystem.directory('/etc').createSync();
+      final File osRelease = fileSystem.file('/etc/os-release');
+
+      handler.addError(osRelease, FileSystemOp.read, const FileSystemException());
+
+      final OperatingSystemUtils utils = OperatingSystemUtils(
+        fileSystem: fileSystem,
+        logger: BufferLogger.test(),
+        platform: FakePlatform(
+          operatingSystem: 'linux',
+          operatingSystemVersion: 'Linux 1.2.3-abcd #1 SMP PREEMPT Sat Jan 1 00:00:00 UTC 2000',
+        ),
+        processManager: fakeProcessManager,
+      );
+      expect(utils.name, 'Linux 1.2.3-abcd');
+    });
+
+    testWithoutContext('Linux name omits kernel release if undefined', () async {
+      const String fakeOsRelease = '''
+      NAME="Name"
+      ID=id
+      ID_LIKE=id_like
+      BUILD_ID=build_id
+      PRETTY_NAME="Pretty Name"
+      ANSI_COLOR="ansi color"
+      HOME_URL="https://home.url/"
+      DOCUMENTATION_URL="https://documentation.url/"
+      SUPPORT_URL="https://support.url/"
+      BUG_REPORT_URL="https://bug.report.url/"
+      LOGO=logo
+      ''';
+      final FileSystem fileSystem = MemoryFileSystem.test();
+      fileSystem.directory('/etc').createSync();
+      fileSystem.file('/etc/os-release').writeAsStringSync(fakeOsRelease);
+
+      final OperatingSystemUtils utils = OperatingSystemUtils(
+        fileSystem: fileSystem,
+        logger: BufferLogger.test(),
+        platform: FakePlatform(
+          operatingSystem: 'linux',
+          operatingSystemVersion: 'undefinedOperatingSystemVersion',
+        ),
+        processManager: fakeProcessManager,
+      );
+      expect(utils.name, 'Pretty Name');
+    });
   });
 
   testWithoutContext('If unzip fails, include stderr in exception text', () {