ConfigurationBinder fails to bind class that implements IDictionary #77246
Description
Description
Binding a Configuration to a class that implements IDictionary<string,T> always results in an empty Dictionary.
The set function throws a System.Reflection.TargetException. I think the problem is that the setter is reflected by Dictionary and not the actual type.
Reproduction Steps
Small test class:
public class TestDictionaryBinding
{
public class CustomDictionary<TKey, TValue> : Dictionary<TKey, TValue> where TKey : notnull
{
}
public class IDictionaryImplementationClass<TKey, TValue> : IDictionary<TKey, TValue> where TKey : notnull
{
private Dictionary<TKey, TValue> m_dict = new();
public TValue this[TKey key] { get => m_dict[key]; set => m_dict[key] = value; }
public ICollection<TKey> Keys => m_dict.Keys;
public ICollection<TValue> Values => m_dict.Values;
public int Count => m_dict.Count;
public bool IsReadOnly => false;
public void Add(TKey key, TValue value) => m_dict.Add(key, value);
public void Add(KeyValuePair<TKey, TValue> item) => m_dict.Add(item.Key, item.Value);
public void Clear() => m_dict.Clear();
public bool Contains(KeyValuePair<TKey, TValue> item) => m_dict.Contains(item);
public bool ContainsKey(TKey key) => m_dict.ContainsKey(key);
public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex) => throw new NotImplementedException();
public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator() => m_dict.GetEnumerator();
public bool Remove(TKey key) => m_dict.Remove(key);
public bool Remove(KeyValuePair<TKey, TValue> item) => m_dict.Remove(item.Key);
public bool TryGetValue(TKey key, [MaybeNullWhen(false)] out TValue value) => m_dict.TryGetValue(key, out value);
IEnumerator IEnumerable.GetEnumerator() => m_dict.GetEnumerator();
}
[Fact]
public void Test_InterfaceDictionary()
{
var _cfg = new Dictionary<string, string>()
{
{ "key", "value" }
};
var _config = new ConfigurationBuilder()
.AddInMemoryCollection(_cfg!)
.Build();
var _dictionary = _config.Get<Dictionary<string, string>>(); // success
var _dictionaryInterface = _config.Get<IDictionary<string, string>>(); // success
var _customDictionaryClass = _config.Get<CustomDictionary<string, string>>(); // success
var _customIDictionaryImplementation = _config.Get<IDictionaryImplementationClass<string, string>>(); // empty
Assert.Single(_dictionary);
Assert.Single(_dictionaryInterface);
Assert.Single(_customDictionaryClass);
Assert.Single(_customIDictionaryImplementation);
}
}Expected behavior
Items from Configuration should be added to a IDictionary implementation
Actual behavior
Custom IDictionary implementation is empty
Regression?
Was working in
7.0.0-preview.7.22375.6
Known Workarounds
No response
Configuration
Used packages for Test:
Other information
No response