Add test coverage for AttributeCollection, fix bugs and nullable anno…

…tate (#36118) * Add test coverage for AttributeCollection and fix bugs * PR Feedback
dotnet · Oct 12, 2020 · 94c6054 · 94c6054
1 parent 671f99b
commit 94c6054
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Showing 3 changed files with 416 additions and 162 deletions.
diff --git a/...ries/System.ComponentModel.TypeConverter/src/System/ComponentModel/AttributeCollection.cs b/...ries/System.ComponentModel.TypeConverter/src/System/ComponentModel/AttributeCollection.cs
@@ -137,6 +137,11 @@ public virtual Attribute this[Type attributeType]
         {
             get
             {
+                if (attributeType == null)
+                {
+                    throw new ArgumentNullException(nameof(attributeType));
+                }
+
                 lock (s_internalSyncObject)
                 {
                     // 2 passes here for perf. Really!  first pass, we just
@@ -213,6 +218,11 @@ public virtual Attribute this[Type attributeType]
         /// </summary>
         public bool Contains(Attribute attribute)
         {
+            if (attribute == null)
+            {
+                return false;
+            }
+
             Attribute attr = this[attribute.GetType()];
             return attr != null && attr.Equals(attribute);
         }
@@ -245,6 +255,11 @@ public bool Contains(Attribute[] attributes)
         /// </summary>
         protected Attribute GetDefaultAttribute(Type attributeType)
         {
+            if (attributeType == null)
+            {
+                throw new ArgumentNullException(nameof(attributeType));
+            }
+
             lock (s_internalSyncObject)
             {
                 if (s_defaultAttributes == null)
@@ -316,6 +331,11 @@ public bool Matches(Attribute attribute)
         /// </summary>
         public bool Matches(Attribute[] attributes)
         {
+            if (attributes == null)
+            {
+                return true;
+            }
+
             for (int i = 0; i < attributes.Length; i++)
             {
                 if (!Matches(attributes[i]))
@@ -329,7 +349,7 @@ public bool Matches(Attribute[] attributes)
 
         bool ICollection.IsSynchronized => false;
 
-        object ICollection.SyncRoot => null;
+        object ICollection.SyncRoot => this;
 
         int ICollection.Count => Count;