Made formulas added in conventions remove any attached columns

Author: jagregory

src/FluentNHibernate.Specs/Conventions/Fixtures/FormulaConvention.cs

@@ -0,0 +1,20 @@
+using FluentNHibernate.Conventions;
+using FluentNHibernate.Conventions.Instances;
+
+namespace FluentNHibernate.Specs.Conventions.Fixtures
+{
+    public class FormulaConvention : IPropertyConvention, IReferenceConvention
+    {
+        public const string FormulaValue = "select x from y";
+
+        public void Apply(IPropertyInstance instance)
+        {
+            instance.Formula(FormulaValue);
+        }
+
+        public void Apply(IManyToOneInstance instance)
+        {
+            instance.Formula(FormulaValue);
+        }
+    }
+}

src/FluentNHibernate.Specs/Conventions/Fixtures/FormulaTarget.cs

@@ -0,0 +1,21 @@
+using FluentNHibernate.Mapping;
+
+namespace FluentNHibernate.Specs.Conventions.Fixtures
+{
+    public class FormulaTarget
+    {
+        public int Id { get; private set; }
+        public string Prop { get; private set; }
+        public FormulaTarget Target { get; private set; }
+    }
+
+    public class FormulaTargetMap : ClassMap<FormulaTarget>
+    {
+        public FormulaTargetMap()
+        {
+            Id(x => x.Id);
+            Map(x => x.Prop, "a-column");
+            References(x => x.Target);
+        }
+    }
+}

src/FluentNHibernate.Specs/Conventions/FormulaConventionSpecs.cs

@@ -0,0 +1,54 @@
+using System.Linq;
+using FluentNHibernate.Conventions;
+using FluentNHibernate.MappingModel.ClassBased;
+using FluentNHibernate.Specs.Conventions.Fixtures;
+using Machine.Specifications;
+
+namespace FluentNHibernate.Specs.Conventions
+{
+    [Subject(typeof(IPropertyConvention))]
+    public class when_a_formula_is_added_to_a_property
+    {
+        Establish context = () =>
+        {
+            model = new FluentNHibernate.PersistenceModel();
+            model.Conventions.Add<FormulaConvention>();
+            model.Add(new FormulaTargetMap());
+        };
+
+        Because of = () =>
+            mapping = model.BuildMappingFor<FormulaTarget>();
+
+        It should_remove_all_columns_from_the_property = () =>
+            mapping.Properties.Single().Columns.ShouldBeEmpty();
+
+        It should_add_the_formula_to_the_property = () =>
+            mapping.Properties.Single().Formula.ShouldEqual(FormulaConvention.FormulaValue);
+        
+        static FluentNHibernate.PersistenceModel model;
+        static ClassMapping mapping;
+    }
+
+    [Subject(typeof(IReferenceConvention))]
+    public class when_a_formula_is_added_to_a_reference
+    {
+        Establish context = () =>
+        {
+            model = new FluentNHibernate.PersistenceModel();
+            model.Conventions.Add<FormulaConvention>();
+            model.Add(new FormulaTargetMap());
+        };
+
+        Because of = () =>
+            mapping = model.BuildMappingFor<FormulaTarget>();
+
+        It should_remove_all_columns_from_the_property = () =>
+            mapping.References.Single().Columns.ShouldBeEmpty();
+
+        It should_add_the_formula_to_the_property = () =>
+            mapping.References.Single().Formula.ShouldEqual(FormulaConvention.FormulaValue);
+
+        static FluentNHibernate.PersistenceModel model;
+        static ClassMapping mapping;
+    }
+}

src/FluentNHibernate.Specs/FluentNHibernate.Specs.csproj

@@ -103,6 +103,8 @@
     <Compile Include="Conventions\Fixtures\CollectionConvention.cs" />
     <Compile Include="Conventions\Fixtures\FilterClassConvention.cs" />
     <Compile Include="Conventions\Fixtures\FilterTarget.cs" />
+    <Compile Include="Conventions\Fixtures\FormulaConvention.cs" />
+    <Compile Include="Conventions\Fixtures\FormulaTarget.cs" />
     <Compile Include="Conventions\Fixtures\SetCollectionEntity.cs" />
     <Compile Include="Conventions\Fixtures\SetCollectionEntityMap.cs" />
     <Compile Include="Conventions\Fixtures\SetCompositeElementCollectionEntity.cs" />
@@ -113,6 +115,7 @@
     <Compile Include="Conventions\Fixtures\TwoPropertyEntityMap.cs" />
     <Compile Include="Conventions\Fixtures\Value.cs" />
     <Compile Include="Conventions\ForeignKeyConventionSpecs.cs" />
+    <Compile Include="Conventions\FormulaConventionSpecs.cs" />
     <Compile Include="Extensions.cs" />
     <Compile Include="FluentInterface\ClasslikeBehaviors.cs" />
     <Compile Include="FluentInterface\ClassMapSpecs\ClassMapSpecs.Cache.cs" />

src/FluentNHibernate/Conventions/Instances/ManyToOneInstance.cs

@@ -35,7 +35,10 @@ public void Column(string columnName)
         public new void Formula(string formula)
         {
             if (!mapping.IsSpecified("Formula"))
+            {
                 mapping.Formula = formula;
+                mapping.ClearColumns();
+            }
         }
 
         public void CustomClass<T>()

src/FluentNHibernate/Conventions/Instances/PropertyInstance.cs

@@ -189,7 +189,10 @@ public void Column(string columnName)
         public new void Formula(string formula)
         {
             if (!mapping.IsSpecified("Formula"))
+            {
                 mapping.Formula = formula;
+                mapping.ClearColumns();
+            }
         }
 
         public new IGeneratedInstance Generated

src/FluentNHibernate/MappingModel/ColumnBasedMappingBase.cs

@@ -50,7 +50,7 @@ public void AddDefaultColumn(ColumnMapping mapping)
 
         public void ClearColumns()
         {
-            columns.Clear();
+            columns.ClearAll();
         }
 
         public bool Equals(ColumnBasedMappingBase other)

src/FluentNHibernate/MappingModel/ManyToOneMapping.cs

@@ -131,7 +131,7 @@ public void AddDefaultColumn(ColumnMapping column)
 
         public void ClearColumns()
         {
-            columns.Clear();
+            columns.ClearAll();
         }
 
         public override bool IsSpecified(string property)