pkgs/matcher/lib/src/having_matcher.dart

// Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'custom_matcher.dart';
import 'interfaces.dart';
import 'type_matcher.dart';
import 'util.dart';

/// A package-private [TypeMatcher] implementation that handles is returned
/// by calls to [TypeMatcher.having].
class HavingMatcher<T> implements TypeMatcher<T> {
  final TypeMatcher<T> _parent;
  final List<_FunctionMatcher<T>> _functionMatchers;

  HavingMatcher(
    this._parent,
    String description,
    Object? Function(T) feature,
    dynamic matcher,
  ) : _functionMatchers = [_FunctionMatcher<T>(description, feature, matcher)];

  HavingMatcher._fromExisting(
    this._parent,
    String description,
    Object? Function(T) feature,
    dynamic matcher,
    Iterable<_FunctionMatcher<T>>? existing,
  ) : _functionMatchers = [
        ...?existing,
        _FunctionMatcher<T>(description, feature, matcher),
      ];

  @override
  TypeMatcher<T> having(
    Object? Function(T) feature,
    String description,
    dynamic matcher,
  ) => HavingMatcher._fromExisting(
    _parent,
    description,
    feature,
    matcher,
    _functionMatchers,
  );

  @override
  bool matches(dynamic item, Map matchState) {
    for (var matcher in <Matcher>[_parent].followedBy(_functionMatchers)) {
      if (!matcher.matches(item, matchState)) {
        addStateInfo(matchState, {'matcher': matcher});
        return false;
      }
    }
    return true;
  }

  @override
  Description describeMismatch(
    Object? item,
    Description mismatchDescription,
    Map matchState,
    bool verbose,
  ) {
    var matcher = matchState['matcher'] as Matcher;
    matcher.describeMismatch(
      item,
      mismatchDescription,
      matchState['state'] as Map,
      verbose,
    );
    return mismatchDescription;
  }

  @override
  Description describe(Description description) => description
      .add('')
      .addDescriptionOf(_parent)
      .add(' with ')
      .addAll('', ' and ', '', _functionMatchers);
}

class _FunctionMatcher<T> extends CustomMatcher {
  final Object? Function(T value) _feature;

  _FunctionMatcher(String name, this._feature, Object? matcher)
    : super('`$name`:', '`$name`', matcher);

  @override
  Object? featureValueOf(covariant T actual) => _feature(actual);
}