co19/LanguageFeatures/Patterns/null_check_A02_t01

[scheglov]

FAILED: dart2analyzer-none release_arm64 co19/LanguageFeatures/Patterns/null_check_A02_t01
Expected: Pass
Actual: MissingCompileTimeError

--- Command "dart2analyzer" (took 16ms):
DART_CONFIGURATION=ReleaseARM64 sdk/bin/dart --packages=.dart_tool/package_config.json pkg/analyzer_cli/bin/analyzer.dart --use-analysis-driver-memory-byte-store --dart-sdk=/Users/scheglov/Source/Dart/sdk.git/sdk/sdk -Dtest_runner.configuration=custom-configuration-1 --enable-experiment=patterns --ignore-unrecognized-flags --packages=/Users/scheglov/Source/Dart/sdk.git/sdk/.dart_tool/package_config.json --format=json /Users/scheglov/Source/Dart/sdk.git/sdk/tests/co19/src/LanguageFeatures/Patterns/null_check_A02_t01.dart

static error failures:
- Unexpected error at line 25, column 16, length 1: STATIC_WARNING.UNNECESSARY_NULL_CHECK_PATTERN

- Unexpected error at line 39, column 20, length 1: STATIC_WARNING.UNNECESSARY_NULL_CHECK_PATTERN

- Unexpected error at line 51, column 11, length 1: STATIC_WARNING.UNNECESSARY_NULL_CHECK_PATTERN

--- Re-run this test:
python3 tools/test.py -m release -c dart2analyzer -a arm64 co19/LanguageFeatures/Patterns/null_check_A02_t01

Code

String test1(int? x) {
  switch (x) {
    case int? v1! && == 1 || int? v1?:
//                                  ^
// [analyzer] STATIC_WARNING.UNNECESSARY_NULL_CHECK_PATTERN
// [cfe] The null-check pattern will have no effect because the matched type isn't nullable.
      return "match-1";
    case int v2?:
      return "match-2";
    default:
      return "no match";
  }
}

In case int v2?: the matched type is int, by the same reason why it is int for int? v1? in the previous case - we have already executed int? v1!.