[flutter_tools] Unhandled ArgumentError in TestCommand._parseTestArgument when path contains Windows reserved characters #191896

Crash Report Details

• Signature: ArgumentError at _Uri._checkWindowsPathReservedCharacters at dart:core/uri.dart-16ba610a
• Exception: ArgumentError
• Volume: 259 crashes (12.3% share of Top 10 in Flutter 3.47.1 stable)
• Error Message: Invalid argument(s): Illegal character in path

Stack Trace

_Uri._checkWindowsPathReservedCharacters (dart:core/uri.dart:2169)
_Uri._makeWindowsFileUrl (dart:core/uri.dart:2242)
new _Uri.file (dart:core/uri.dart:2132)
TestCommand._parseTestArgument (package:flutter_tools/src/commands/test.dart:791)
TestCommand.verifyThenRunCommand (package:flutter_tools/src/commands/test.dart:362)

Description & Root Cause

When running flutter test on Windows (or when target arguments are formatted with Windows paths), TestCommand._parseTestArgument parses target path arguments by calling Uri.file(filePart).
On Windows, Uri.file invokes _Uri._checkWindowsPathReservedCharacters, which disallows wildcard / glob characters (*, ?), redirection characters (<, >, |), quotes ("), or malformed colons. If a user specifies a glob or pattern that is not expanded by their shell (common on Windows cmd.exe or PowerShell, e.g. flutter test test/*_test.dart), Uri.file throws an ArgumentError: Invalid argument(s): Illegal character in path.

Because _parseTestArgument does not catch ArgumentError, the exception is unhandled and causes flutter_tools to crash with an unhandled tool crash report instead of exiting cleanly with a user-friendly ToolExit.

Reproduction

On Windows (or with Windows path parsing in tests), run:

flutter test "test/*_test.dart"

Actual Result:
Crash with ArgumentError: Invalid argument(s): Illegal character in path.

Expected Result:
Clean exit with ToolExit reporting invalid test path/target syntax.