Ignore invalid description property in vswhere.exe JSON output (#106836)
The `flutter doctor` command uses `vswhere.exe` to verify the Visual Studio installation. This `vswhere.exe` is known to encode its output incorrectly. This is problematic as the `description` property is localized, and in certain languages this results in invalid JSON due to the incorrect encoding.
This change introduces a fallback to our `vswhere.exe` output parsing logic: if parsing JSON fails, remove the `description` property and retry parsing the JSON.
This fix was also tested on the outputs provided here: https://github.com/flutter/flutter/issues/106601#issuecomment-1170138123
Addresses https://github.com/flutter/flutter/issues/106601
diff --git a/packages/flutter_tools/lib/src/windows/visual_studio.dart b/packages/flutter_tools/lib/src/windows/visual_studio.dart
index e5bef84..3d9fe48 100644
--- a/packages/flutter_tools/lib/src/windows/visual_studio.dart
+++ b/packages/flutter_tools/lib/src/windows/visual_studio.dart
@@ -23,11 +23,16 @@
required Logger logger,
}) : _platform = platform,
_fileSystem = fileSystem,
- _processUtils = ProcessUtils(processManager: processManager, logger: logger);
+ _processUtils = ProcessUtils(processManager: processManager, logger: logger),
+ _logger = logger;
final FileSystem _fileSystem;
final Platform _platform;
final ProcessUtils _processUtils;
+ final Logger _logger;
+
+ /// Matches the description property from the vswhere.exe JSON output.
+ final RegExp _vswhereDescriptionProperty = RegExp(r'\s*"description"\s*:\s*".*"\s*,?');
/// True if Visual Studio installation was found.
///
@@ -294,9 +299,8 @@
...requirementArguments,
], encoding: encoding);
if (whereResult.exitCode == 0) {
- final List<Map<String, dynamic>> installations =
- (json.decode(whereResult.stdout) as List<dynamic>).cast<Map<String, dynamic>>();
- if (installations.isNotEmpty) {
+ final List<Map<String, dynamic>>? installations = _tryDecodeVswhereJson(whereResult.stdout);
+ if (installations != null && installations.isNotEmpty) {
return VswhereDetails.fromJson(validateRequirements, installations[0]);
}
}
@@ -304,12 +308,41 @@
// Thrown if vswhere doesn't exist; ignore and return null below.
} on ProcessException {
// Ignored, return null below.
- } on FormatException {
- // may be thrown if invalid JSON is returned.
}
return null;
}
+ List<Map<String, dynamic>>? _tryDecodeVswhereJson(String vswhereJson) {
+ List<dynamic>? result;
+ FormatException? originalError;
+ try {
+ // Some versions of vswhere.exe are known to encode their output incorrectly,
+ // resulting in invalid JSON in the 'description' property when interpreted
+ // as UTF-8. First, try to decode without any pre-processing.
+ try {
+ result = json.decode(vswhereJson) as List<dynamic>;
+ } on FormatException catch (error) {
+ // If that fails, remove the 'description' property and try again.
+ // See: https://github.com/flutter/flutter/issues/106601
+ vswhereJson = vswhereJson.replaceFirst(_vswhereDescriptionProperty, '');
+
+ _logger.printTrace('Failed to decode vswhere.exe JSON output. $error'
+ 'Retrying after removing the unused description property:\n$vswhereJson');
+
+ originalError = error;
+ result = json.decode(vswhereJson) as List<dynamic>;
+ }
+ } on FormatException {
+ // Removing the description property didn't help.
+ // Report the original decoding error on the unprocessed JSON.
+ _logger.printWarning('Warning: Unexpected vswhere.exe JSON output. $originalError'
+ 'To see the full JSON, run flutter doctor -vv.');
+ return null;
+ }
+
+ return result.cast<Map<String, dynamic>>();
+ }
+
/// Returns the details of the best available version of Visual Studio.
///
/// If there's a version that has all the required components, that
diff --git a/packages/flutter_tools/test/general.shard/windows/visual_studio_test.dart b/packages/flutter_tools/test/general.shard/windows/visual_studio_test.dart
index f63fce5..6f2aa45 100644
--- a/packages/flutter_tools/test/general.shard/windows/visual_studio_test.dart
+++ b/packages/flutter_tools/test/general.shard/windows/visual_studio_test.dart
@@ -92,6 +92,23 @@
},
};
+const String _malformedDescriptionResponse = r'''
+[
+ {
+ "installationPath": "C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\Community",
+ "displayName": "Visual Studio Community 2019",
+ "description": "This description has too many "quotes",
+ "installationVersion": "16.2.29306.81",
+ "isRebootRequired": false,
+ "isComplete": true,
+ "isPrerelease": false,
+ "catalog": {
+ "productDisplayVersion": "16.2.5"
+ }
+ }
+]
+''';
+
// Arguments for a vswhere query to search for an installation with the
// requirements.
const List<String> _requirements = <String>[
@@ -124,7 +141,7 @@
fileSystem.file(vswherePath).createSync(recursive: true);
fileSystem.file(cmakePath).createSync(recursive: true);
final String finalResponse = responseOverride
- ?? (response != null ? json.encode(<Map<String, dynamic>>[response]) : '');
+ ?? (response != null ? json.encode(<Map<String, dynamic>>[response]) : '[]');
final List<String> requirementArguments = requiredComponents == null
? <String>[]
: <String>['-requires', ...requiredComponents];
@@ -323,7 +340,7 @@
logger: logger,
processManager: processManager,
);
- return VisualStudioFixture(visualStudio, fileSystem, processManager);
+ return VisualStudioFixture(visualStudio, fileSystem, processManager, logger);
}
// Set all vswhere query with the required components return null.
@@ -717,7 +734,7 @@
expect(visualStudio.fullVersion, equals('16.2.29306.81'));
});
- testWithoutContext('cmakePath returns null when VS is present but when vswhere returns invalid JSON', () {
+ testWithoutContext('Warns and returns no installation when VS is present but vswhere returns invalid JSON', () {
final VisualStudioFixture fixture = setUpVisualStudio();
final VisualStudio visualStudio = fixture.visualStudio;
@@ -729,7 +746,19 @@
fixture.processManager,
);
+ expect(visualStudio.isInstalled, isFalse);
+ expect(visualStudio.isComplete, isFalse);
+ expect(visualStudio.isLaunchable, isFalse);
+ expect(visualStudio.isPrerelease, isFalse);
+ expect(visualStudio.isRebootRequired, isFalse);
+ expect(visualStudio.hasNecessaryComponents, isFalse);
+ expect(visualStudio.displayName, isNull);
+ expect(visualStudio.displayVersion, isNull);
+ expect(visualStudio.installLocation, isNull);
+ expect(visualStudio.fullVersion, isNull);
expect(visualStudio.cmakePath, isNull);
+
+ expect(fixture.logger.warningText, contains('Warning: Unexpected vswhere.exe JSON output'));
});
testWithoutContext('Everything returns good values when VS is present with all components', () {
@@ -941,6 +970,26 @@
expect(visualStudio.cmakeGenerator, equals('Visual Studio 16 2019'));
expect(visualStudio.displayVersion, equals('\u{FFFD}'));
});
+
+ testWithoutContext('Ignores malformed JSON in description property', () {
+ setMockVswhereResponse(
+ fixture.fileSystem,
+ fixture.processManager,
+ _requirements,
+ <String>['-version', '16'],
+ null,
+ _malformedDescriptionResponse,
+ );
+
+ expect(visualStudio.isInstalled, true);
+ expect(visualStudio.isAtLeastMinimumVersion, true);
+ expect(visualStudio.hasNecessaryComponents, true);
+ expect(visualStudio.cmakePath, equals(cmakePath));
+ expect(visualStudio.cmakeGenerator, equals('Visual Studio 16 2019'));
+ expect(visualStudio.displayVersion, equals('16.2.5'));
+
+ expect(fixture.logger.warningText, isEmpty);
+ });
});
group(VswhereDetails, () {
@@ -1037,9 +1086,10 @@
}
class VisualStudioFixture {
- VisualStudioFixture(this.visualStudio, this.fileSystem, this.processManager);
+ VisualStudioFixture(this.visualStudio, this.fileSystem, this.processManager, this.logger);
final VisualStudio visualStudio;
final FileSystem fileSystem;
final FakeProcessManager processManager;
+ final BufferLogger logger;
}
