if there is dependency from the same class

in fields, property, in difficult field and so on - distinct
+ equals and unique relations between classes in RelationshipCollection

Author: akravtsova

src/PlantUmlClassDiagramGenerator.Library/ClassDiagramGenerator/RelationshipGenerator.cs

@@ -19,6 +19,6 @@ public static string[] GenerateRelationships(RelationshipCollection relationship
         List<string> strings = new List<string>();
         strings.AddRange(relationshipCollection.Select(r => r.ToString()));
 
-        return strings.ToArray();
+        return strings.Distinct().ToArray();
     }
 }

src/PlantUmlClassDiagramGenerator.Library/Enums/SystemCollectionsTypes.cs

@@ -16,6 +16,7 @@ public enum SystemCollectionsTypes
     SortedList,
     Stack,
     StructuralComparisons,
+    List, // Actually not SystemCollections but... meh
 
     // structs
     DictionaryEntry,

src/PlantUmlClassDiagramGenerator.Library/Relationship.cs

@@ -13,4 +13,31 @@ public override string ToString()
     {
         return $"{baseTypeName.Identifier}{baseLabel} {symbol}{subLabel} {subTypeName.Identifier}{centerLabel}";
     }
+
+    private bool Equals(Relationship other)
+    {
+        return Equals(baseTypeName, other.baseTypeName) 
+               && Equals(subTypeName, other.subTypeName) 
+               && Equals(baseLabel, other.baseLabel)
+               && Equals(subLabel, other.subLabel);
+    }
+
+    public override bool Equals(object obj)
+    {
+        if (ReferenceEquals(null, obj)) return false;
+        if (ReferenceEquals(this, obj)) return true;
+        if (obj.GetType() != this.GetType()) return false;
+        return Equals((Relationship)obj);
+    }
+
+    public override int GetHashCode()
+    {
+        unchecked
+        {
+            var hashCode = (baseTypeName != null ? baseTypeName.GetHashCode() : 0);
+            hashCode = (hashCode * 397) ^ (subTypeName != null ? subTypeName.GetHashCode() : 0);
+            hashCode = (hashCode * 397) ^ (baseLabel != null ? baseLabel.GetHashCode() : 0);
+            return hashCode;
+        }
+    }
 }

src/PlantUmlClassDiagramGenerator.Library/RelationshipCollection.cs

@@ -142,12 +142,16 @@ private static TypeNameText GetLeafName(string attributeName, TypeSyntax typeSyn
     private void AddeRationship(PlantUmlAssociationAttribute attribute, TypeNameText leafName, TypeNameText rootName)
     {
         var symbol = string.IsNullOrEmpty(attribute.Association) ? "--" : attribute.Association;
-        items.Add(new Relationship(rootName, leafName, symbol, attribute.RootLabel, attribute.LeafLabel, attribute.Label));
+        var relationship = new Relationship(rootName, leafName, symbol, attribute.RootLabel, attribute.LeafLabel, attribute.Label);
+        if (!items.Contains(relationship))
+            items.Add(relationship);
     }
 
     private void AddRelationship(TypeNameText leafName, TypeNameText rootName, string symbol, string nodeIdentifier)
     {
-        items.Add(new Relationship(rootName, leafName, symbol, "", nodeIdentifier + leafName.TypeArguments));
+        var relationship = new Relationship(rootName, leafName, symbol, "", nodeIdentifier + leafName.TypeArguments);
+        if (!items.Contains(relationship))
+            items.Add(relationship);
     }
 
     public IEnumerator<Relationship> GetEnumerator()

src/PlantUmlClassDiagramGenerator.Library/TypeNameText.cs

@@ -72,4 +72,25 @@ public static TypeNameText From(BaseTypeDeclarationSyntax syntax)
             TypeArguments = typeArgs
         };
     }
+
+    private bool Equals(TypeNameText other)
+    {
+        return Identifier == other.Identifier && TypeArguments == other.TypeArguments;
+    }
+
+    public override bool Equals(object obj)
+    {
+        if (ReferenceEquals(null, obj)) return false;
+        if (ReferenceEquals(this, obj)) return true;
+        if (obj.GetType() != this.GetType()) return false;
+        return Equals((TypeNameText)obj);
+    }
+
+    public override int GetHashCode()
+    {
+        unchecked
+        {
+            return ((Identifier != null ? Identifier.GetHashCode() : 0) * 397) ^ (TypeArguments != null ? TypeArguments.GetHashCode() : 0);
+        }
+    }
 }