@Test
public void testDoNotReplace() throws Exception {

  final String original = "void main() { int a = 1, b = 2; int c = 3; }";
  final TranslationUnit tu = ParseHelper.parse(original);
  final List<VariableDeclToExprReductionOpportunity> ops =
      VariableDeclToExprReductionOpportunities
      .findOpportunities(MakeShaderJobFromFragmentShader.make(tu), new ReducerContext(false,
          ShadingLanguageVersion.ESSL_100,
          new RandomWrapper(0), new IdGenerator()));
  // There should be no opportunities as the preserve semantics is enabled.
  assertTrue(ops.isEmpty());
}