Support projections arguments in Coalesce and other QueryOver extensions

Fixes #767

Author: bahusoid

src/NHibernate.Test/Criteria/Lambda/Mappings.hbm.xml

@@ -9,6 +9,7 @@
 		</id>
 		<discriminator type="string" />
 		<property name="Name" />
+		<property name="Nickname" />
 		<property name="Age" />
 		<property name="BirthDate" />
 		<property name="BirthDateAsDateTimeOffset" type="NHibernate.Test.DateTimeOffsetUserType, NHibernate.Test" />

src/NHibernate.Test/Criteria/Lambda/Model.cs

@@ -26,6 +26,7 @@ public Person()
 
 		public virtual int					Id			{ get; set; }
 		public virtual string				Name		{ get; set; }
+		public virtual string				Nickname	{ get; set; }
 		public virtual int					Age			{ get; set; }
 		public virtual PersonGender			Gender		{ get; set; }
 		public virtual int					Height		{ get; set; }

src/NHibernate.Test/Criteria/Lambda/RestrictionsFixture.cs

@@ -284,11 +284,15 @@ public void FunctionExtensions()
 					.Add(Restrictions.Eq(Projections.SqlFunction("length", NHibernateUtil.String, Projections.Property("Name")), 4))
 					.Add(Restrictions.Eq(Projections.SqlFunction("bit_length", NHibernateUtil.String, Projections.Property("Name")), 32))
 					.Add(Restrictions.Eq(Projections.SqlFunction("substring", NHibernateUtil.String, Projections.Property("Name"), Projections.Constant(1), Projections.Constant(2)), "te"))
+					.Add(Restrictions.Eq(Projections.SqlFunction("substring", NHibernateUtil.String, Projections.Property("Name"), Projections.Property("Age"), Projections.Constant(2)), "te"))
 					.Add(Restrictions.Eq(Projections.SqlFunction("locate", NHibernateUtil.String, Projections.Constant("e"), Projections.Property("Name"), Projections.Constant(1)), 2))
+					.Add(Restrictions.Eq(Projections.SqlFunction("locate", NHibernateUtil.String, Projections.Constant("e"), Projections.Property("Name"), Projections.Property("Age")), 2))
 					.Add(Restrictions.Eq(Projections.SqlFunction("coalesce", NHibernateUtil.Object, Projections.Property("Name"), Projections.Constant("not-null-val")), "test"))
+					.Add(Restrictions.Eq(Projections.SqlFunction("coalesce", NHibernateUtil.Object, Projections.Property("Name"), Projections.Property("Nickname")), "test"))
 					.Add(Restrictions.Eq(Projections.SqlFunction("coalesce", NHibernateUtil.Object, Projections.Property("NullableIsParent"), Projections.Constant(true)), true))
 					.Add(Restrictions.Eq(Projections.SqlFunction("concat", NHibernateUtil.String, Projections.Property("Name"), Projections.Constant(", "), Projections.Property("Name")), "test, test"))
-					.Add(Restrictions.Eq(Projections.SqlFunction("mod", NHibernateUtil.Int32, Projections.Property("Height"), Projections.Constant(10)), 0));
+					.Add(Restrictions.Eq(Projections.SqlFunction("mod", NHibernateUtil.Int32, Projections.Property("Height"), Projections.Constant(10)), 0))
+					.Add(Restrictions.Eq(Projections.SqlFunction("mod", NHibernateUtil.Int32, Projections.Property("Height"), Projections.Property("Age")), 0));
 
 			IQueryOver<Person> actual =
 				CreateTestQueryOver<Person>()
@@ -314,11 +318,15 @@ public void FunctionExtensions()
 					.And(p => p.Name.StrLength() == 4)
 					.And(p => p.Name.BitLength() == 32)
 					.And(p => p.Name.Substr(1, 2) == "te")
+					.And(p => p.Name.Substr(p.Age, 2) == "te")
 					.And(p => p.Name.CharIndex("e", 1) == 2)
+					.And(p => p.Name.CharIndex("e", p.Age) == 2)
 					.And(p => p.Name.Coalesce("not-null-val") == "test")
+					.And(p => p.Name.Coalesce(p.Nickname) == "test")
 					.And(p => p.NullableIsParent.Coalesce(true) == true)
 					.And(p => Projections.Concat(p.Name, ", ", p.Name) == "test, test")
-					.And(p => p.Height.Mod(10) == 0);
+					.And(p => p.Height.Mod(10) == 0)
+					.And(p => p.Height.Mod(p.Age) == 0);
 
 			AssertCriteriaAreEqual(expected, actual);
 		}
@@ -339,4 +347,4 @@ public void FunctionExtensionsProperty()
 			AssertCriteriaAreEqual(expected, actual);
 		}
 	}
-}
+}

src/NHibernate/Criterion/ProjectionsExtensions.cs

@@ -272,9 +272,9 @@ public static string Substr(this string stringProperty, int startIndex, int leng
 		internal static IProjection ProcessSubstr(MethodCallExpression methodCallExpression)
 		{
 			IProjection property = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[0]).AsProjection();
-			object startIndex = ExpressionProcessor.FindValue(methodCallExpression.Arguments[1]);
-			object length = ExpressionProcessor.FindValue(methodCallExpression.Arguments[2]);
-			return Projections.SqlFunction("substring", NHibernateUtil.String, property, Projections.Constant(startIndex), Projections.Constant(length));
+			var startIndex = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[1]);
+			var length = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[2]);
+			return Projections.SqlFunction("substring", NHibernateUtil.String, property, startIndex.AsProjection(), length.AsProjection());
 		}
 
 		/// <summary>
@@ -289,9 +289,9 @@ public static int CharIndex(this string stringProperty, string theChar, int star
 		internal static IProjection ProcessCharIndex(MethodCallExpression methodCallExpression)
 		{
 			IProjection property = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[0]).AsProjection();
-			object theChar = ExpressionProcessor.FindValue(methodCallExpression.Arguments[1]);
-			object startLocation = ExpressionProcessor.FindValue(methodCallExpression.Arguments[2]);
-			return Projections.SqlFunction("locate", NHibernateUtil.String, Projections.Constant(theChar), property, Projections.Constant(startLocation));
+			var theChar = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[1]);
+			var startLocation = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[2]);
+			return Projections.SqlFunction("locate", NHibernateUtil.String, theChar.AsProjection(), property, startLocation.AsProjection());
 		}
 
 		/// <summary>
@@ -315,8 +315,8 @@ public static T Coalesce<T>(this T objectProperty, T replaceValueIfIsNull)
 		internal static IProjection ProcessCoalesce(MethodCallExpression methodCallExpression)
 		{
 			IProjection property = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[0]).AsProjection();
-			object replaceValueIfIsNull = ExpressionProcessor.FindValue(methodCallExpression.Arguments[1]);
-			return Projections.SqlFunction("coalesce", NHibernateUtil.Object, property, Projections.Constant(replaceValueIfIsNull));
+			var replaceValueIfIsNull = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[1]);
+			return Projections.SqlFunction("coalesce", NHibernateUtil.Object, property, replaceValueIfIsNull.AsProjection());
 		}
 
 		/// <summary>
@@ -331,8 +331,8 @@ public static int Mod(this int numericProperty, int divisor)
 		internal static IProjection ProcessMod(MethodCallExpression methodCallExpression)
 		{
 			IProjection property = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[0]).AsProjection();
-			object divisor = ExpressionProcessor.FindValue(methodCallExpression.Arguments[1]);
-			return Projections.SqlFunction("mod", NHibernateUtil.Int32, property, Projections.Constant(divisor));
+			var divisor = ExpressionProcessor.FindMemberProjection(methodCallExpression.Arguments[1]);
+			return Projections.SqlFunction("mod", NHibernateUtil.Int32, property, divisor.AsProjection());
 		}
 
 		/// <summary>