parseExpression method

@visibleForTesting AST parseExpression(String input, String location, { bool? allowAssignments, bool? allowPipes, List<CompileIdentifierMetadata>? exports, })

Implementation

@visibleForTesting
ast.AST parseExpression(
  String input,
  String location, {
  bool? allowAssignments,
  bool? allowPipes,
  List<CompileIdentifierMetadata>? exports,
}) {
  if (input.isEmpty) {
    return ast.EmptyExpr();
  }
  // This is a hack; currently analyzer can only accept valid compilation
  // units into `parseString`, which means we need something valid at the
  // top-level of a Dart file.
  final wrapper = 'void __EXPRESSION__() => $input;';
  final result = parseString(
    content: wrapper,
    path: location,
    throwIfDiagnostics: false,
    featureSet: FeatureSet.fromEnableFlags2(
      sdkLanguageVersion: ExperimentStatus.currentVersion,
      flags: const [
        'non-nullable',
      ],
    ),
  );
  if (result.errors.isNotEmpty) {
    throw ParseException(
      result.errors.map((e) => e.message).join('\n'),
      input,
      location,
    );
  }
  final declared = result.unit.declarations;
  if (declared.length != 1) {
    throw ParseException('Not a valid expression', input, location);
  }

  final function = declared.first as FunctionDeclaration;
  final innerBody = function.functionExpression.body;

  final innerAst = (innerBody as ExpressionFunctionBody).expression;
  return _convertAndValididateExpression(
    innerAst,
    input,
    location,
    allowAssignments: allowAssignments,
    allowPipes: allowPipes,
    exports: exports,
  );
}