public static void LinkedDictionaryTest()
{
LinkedDictionary <string, int> ldEmpty = new LinkedDictionary <string, int>();
LinkedDictionary <string, int> a = new LinkedDictionary <string, int>();
a.Add("a1", 1);
a.Add("a12", 12);
a.Add("a123", 123);
a.Add("a4", 4);
a.Add("a5", 5);
#region Pseudo-LINQ-Extensions
Assert.AreEqual("a1", a.First().Key);
Assert.AreEqual(1, a.First().Value);
Assert.AreEqual("a5", a.Last().Key);
Assert.AreEqual(5, a.Last().Value);
Assert.Throws <InvalidOperationException>(() => ldEmpty.First());
Assert.Throws <InvalidOperationException>(() => ldEmpty.Last());
Assert.DoesNotThrow(() => ldEmpty.FirstOrDefault());
Assert.DoesNotThrow(() => ldEmpty.LastOrDefault());
Assert.AreEqual(default(KeyValuePair <string, int>), ldEmpty.FirstOrDefault());
Assert.AreEqual(default(KeyValuePair <string, int>), ldEmpty.LastOrDefault());
Assert.DoesNotThrow(() => ldEmpty.Reverse());
List <KeyValuePair <string, int> > reversed = new List <KeyValuePair <string, int> >(a.Reverse());
Assert.AreEqual(a.Count, reversed.Count);
Assert.AreEqual("a5", reversed[0].Key);
Assert.AreEqual(5, reversed[0].Value);
Assert.AreEqual("a4", reversed[1].Key);
Assert.AreEqual(4, reversed[1].Value);
Assert.AreEqual("a123", reversed[2].Key);
Assert.AreEqual(123, reversed[2].Value);
Assert.AreEqual("a12", reversed[3].Key);
Assert.AreEqual(12, reversed[3].Value);
Assert.AreEqual("a1", reversed[4].Key);
Assert.AreEqual(1, reversed[4].Value);
#endregion
Assert.AreEqual(5, a.Count);
Assert.IsTrue(a.ContainsKey("a4"));
Assert.IsTrue(a.ContainsKey("a123"));
Assert.IsTrue(a.Remove("a123"));
Assert.IsFalse(a.Remove("a123"));
Assert.IsFalse(a.ContainsKey("a123"));
Assert.AreEqual(4, a.Count);
List <string> keys = new List <string>(a.Keys);
List <int> values = new List <int>(a.Values);
List <KeyValuePair <string, int> > kv = new List <KeyValuePair <string, int> >(a);
Assert.AreEqual("a1", keys[0]);
Assert.AreEqual("a12", keys[1]);
Assert.AreEqual("a4", keys[2]);
Assert.AreEqual("a5", keys[3]);
Assert.AreEqual(1, values[0]);
Assert.AreEqual(12, values[1]);
Assert.AreEqual(4, values[2]);
Assert.AreEqual(5, values[3]);
Assert.AreEqual("a1", kv[0].Key);
Assert.AreEqual("a12", kv[1].Key);
Assert.AreEqual("a4", kv[2].Key);
Assert.AreEqual("a5", kv[3].Key);
Assert.AreEqual(1, kv[0].Value);
Assert.AreEqual(12, kv[1].Value);
Assert.AreEqual(4, kv[2].Value);
Assert.AreEqual(5, kv[3].Value);
a.Clear();
Assert.AreEqual(0, a.Count);
}