Use null propagation where possible (#651)

+semver:patch

src/FluentNHibernate/Automapping/AutoMapping.cs

@@ -133,8 +133,7 @@ public AutoJoinedSubClassPart<TSubclass> JoinedSubClass<TSubclass>(string keyCol
         var genericType = typeof(AutoJoinedSubClassPart<>).MakeGenericType(typeof(TSubclass));
         var joinedclass = (AutoJoinedSubClassPart<TSubclass>)Activator.CreateInstance(genericType, keyColumn);
 
-        if (action is not null)
-            action(joinedclass);
+        action?.Invoke(joinedclass);
 
         providers.Subclasses[typeof(TSubclass)] = joinedclass;
 
@@ -167,8 +166,7 @@ public AutoSubClassPart<TSubclass> SubClass<TSubclass>(object discriminatorValue
         var genericType = typeof(AutoSubClassPart<>).MakeGenericType(typeof(TSubclass));
         var subclass = (AutoSubClassPart<TSubclass>)Activator.CreateInstance(genericType, null, discriminatorValue);
 
-        if (action is not null)
-            action(subclass);
+        action?.Invoke(subclass);
 
         // remove any mappings for the same type, then re-add
         providers.Subclasses[typeof(TSubclass)] = subclass;

src/FluentNHibernate/Automapping/AutoSubClassPart.cs

@@ -70,7 +70,7 @@ public void SubClass<TSubclass>(string discriminatorValue, Action<AutoSubClassPa
         var genericType = typeof(AutoSubClassPart<>).MakeGenericType(typeof(TSubclass));
         var subclass = (AutoSubClassPart<TSubclass>)Activator.CreateInstance(genericType, discriminatorValue);
 
-        if (action is not null) action(subclass);
+        action?.Invoke(subclass);
 
         providers.Subclasses[typeof(TSubclass)] = subclass;
     }

src/FluentNHibernate/Automapping/Steps/PropertyStep.cs

@@ -47,9 +47,8 @@ private bool HasExplicitTypeConvention(Member property)
 
                 var criteria = new ConcreteAcceptanceCriteria<IPropertyInspector>();
                 var acceptance = c as IConventionAcceptance<IPropertyInspector>;
-
-                if (acceptance is not null)
-                    acceptance.Accept(criteria);
+
+                acceptance?.Accept(criteria);
 
                 var propertyMapping = new PropertyMapping
                 {

src/FluentNHibernate/Mapping/ClasslikeMapBase.cs

@@ -294,7 +294,7 @@ ComponentPart<TComponent> Component<TComponent>(Member member, Action<ComponentP
 
         var part = new ComponentPart<TComponent>(typeof(T), member);
 
-        if (action is not null) action(part);
+        action?.Invoke(part);
 
         providers.Components.Add(part);
 

src/FluentNHibernate/Mapping/CompositeIdentityPart.cs

@@ -162,8 +162,7 @@ protected virtual CompositeIdentityPart<T> KeyReference(Member member, IEnumerab
 
         var keyPart = new KeyManyToOnePart(key);
 
-        if (customMapping is not null)
-            customMapping(keyPart);
+        customMapping?.Invoke(keyPart);
 
         keys.Add(key);            
 
@@ -173,10 +172,7 @@ protected virtual CompositeIdentityPart<T> KeyReference(Member member, IEnumerab
     public virtual CompositeIdentityPart<T> CustomType<CType>()
     {
         var key = keys.Where(x => x is KeyPropertyMapping).Cast<KeyPropertyMapping>().LastOrDefault();
-        if (key is not null)
-        {
-            key.Set(x => x.Type, Layer.Defaults, new TypeReference(typeof(CType)));
-        }
+        key?.Set(x => x.Type, Layer.Defaults, new TypeReference(typeof(CType)));
         return this;
     }
 

src/FluentNHibernate/Mapping/ManyToManyPart.cs

@@ -125,8 +125,7 @@ public ManyToManyPart<TChild> AsTernaryAssociation(string indexColumn, string va
         manyToManyIndex.Column(indexColumn);
         manyToManyIndex.Type(indexType);
 
-        if (indexAction is not null)
-            indexAction(manyToManyIndex);
+        indexAction?.Invoke(manyToManyIndex);
 
         ChildKeyColumn(valueColumn);
         valueType = typeOfValue;
@@ -154,8 +153,7 @@ public ManyToManyPart<TChild> AsTernaryAssociation(Type indexType, string indexC
         manyToManyIndex.Column(indexColumn);
         manyToManyIndex.Type(indexType);
 
-        if (indexAction is not null)
-            indexAction(manyToManyIndex);
+        indexAction?.Invoke(manyToManyIndex);
 
         ChildKeyColumn(valueColumn);
         valueType = typeOfValue;

src/FluentNHibernate/Mapping/Member.cs

@@ -290,10 +290,7 @@ public PropertyMember(PropertyInfo member)
 
     MethodMember GetMember(MethodInfo method)
     {
-        if (method is null)
-            return null;
-
-        return (MethodMember)method.ToMember();
+        return (MethodMember)method?.ToMember();
     }
 
     public override void SetValue(object target, object value)

src/FluentNHibernate/Mapping/ToManyBase.cs

@@ -405,8 +405,7 @@ private void CreateIndexMapping(Action<IndexPart> customIndex)
     {
         var indexPart = new IndexPart(typeof(T));
 
-        if (customIndex is not null)
-            customIndex(indexPart);
+        customIndex?.Invoke(indexPart);
 
 #pragma warning disable 612,618
         indexMapping = indexPart.GetIndexMapping();
@@ -418,8 +417,7 @@ private void CreateListIndexMapping(Action<ListIndexPart> customIndex)
         indexMapping = new IndexMapping();
         var builder = new ListIndexPart(indexMapping);
 
-        if (customIndex is not null)
-            customIndex(builder);
+        customIndex?.Invoke(builder);
     }
 
     /// <summary>
@@ -445,7 +443,7 @@ public T Element(string columnName)
     public T Element(string columnName, Action<ElementPart> customElementMapping)
     {
         Element(columnName);
-        if (customElementMapping is not null) customElementMapping(elementPart);
+        customElementMapping?.Invoke(elementPart);
         return (T)this;
     }
 

src/FluentNHibernate/MappingModel/ClassBased/ReferenceComponentMapping.cs

@@ -31,8 +31,7 @@ public void AcceptVisitor(IMappingModelVisitor visitor)
     {
         visitor.ProcessComponent(this);
 
-        if (mergedComponent is not null)
-            mergedComponent.AcceptVisitor(visitor);
+        mergedComponent?.AcceptVisitor(visitor);
     }
 
     public bool IsSpecified(string name)

src/FluentNHibernate/MappingModel/TypeReference.cs

@@ -80,10 +80,7 @@ public bool IsGenericTypeDefinition
 
     public Type GetGenericTypeDefinition()
     {
-        if (innerType is null)
-            return null;
-
-        return innerType.GetGenericTypeDefinition();
+        return innerType?.GetGenericTypeDefinition();
     }
 
     public Type GenericTypeDefinition

src/FluentNHibernate/Visitors/ComponentReferenceResolutionVisitor.cs

@@ -29,10 +29,7 @@ public ExternalComponentMapping Resolve(ComponentResolutionContext context, IEnu
 
         var provider = providers.SingleOrDefault();
 
-        if (provider is null)
-            return null;
-
-        return provider.GetComponentMapping();
+        return provider?.GetComponentMapping();
     }
 }
 

src/FluentNHibernate/Visitors/ConventionVisitor.cs

@@ -266,8 +266,7 @@ static void Apply<TInspector, TInstance>(IEnumerable conventions, TInstance inst
             var criteria = new ConcreteAcceptanceCriteria<TInspector>();
             var acceptance = convention as IConventionAcceptance<TInspector>;
 
-            if (acceptance is not null)
-                acceptance.Accept(criteria);
+            acceptance?.Accept(criteria);
 
             if (criteria.Matches(instance))
                 convention.Apply(instance);

src/FluentNHibernate/Visitors/RelationshipPairingVisitor.cs

@@ -193,10 +193,7 @@ static CollectionMapping FindAlternative(IEnumerable<CollectionMapping> rs, Coll
             .OrderBy(x => x.Differences)
             .FirstOrDefault();
 
-        if (alternative is null)
-            return null;
-
-        return alternative.Collection;
+        return alternative?.Collection;
     }
 
     static bool AnyHaveSameLikeness(IEnumerable<LikenessContainer> likenesses, LikenessContainer current)