Support for custom default in absent case

README.md

@@ -21,7 +21,7 @@ Key: ✔️ = Good, ⚠️ = Problematic, ⛔ = Bad
 
 Add the dependency:
 
-`libraryDependencies += "com.ryanstull" %% "scalanullsafe" % "1.0.3"`
+`libraryDependencies += "com.ryanstull" %% "scalanullsafe" % "1.1.0"`
 
 Example use:
 
@@ -113,6 +113,17 @@ All of the above work for method invocation as well as property access, and the
 `?(someObj.methodA().field1.twoArgMethod("test",1).otherField)`
 
  will be translated properly.
+
+For the `?` macro, you can also provide a custom default instead of null, by passing it in as the second
+parameter.  For example
+
+```
+case class Person(name: String)
+
+val person: Person = null
+
+assert(?(person.name,"") == "")
+```
 
 ## Performance
 
@@ -148,4 +159,7 @@ equivalent performance.
 
 * Using the `?` macro on an expression whose type is `<: AnyVal`, will result in returning the corresponding java wrapper
 type.  For example `?(a.getInt)` will return `java.lang.Integer` instead of `Int` because the return type for this macro must
-be nullable.  The conversions are the default ones defined in `scala.Predef`
+be nullable.  The conversions are the default ones defined in `scala.Predef`
+
+* If you're having trouble with resolving the correct method when using the `?` macro with a default arg, try explicitly
+specifying the type of the default

src/main/scala/com/ryanstull/nullsafe/package.scala

@@ -21,6 +21,17 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Byte): java.lang.Byte = macro qMarkImpl[java.lang.Byte]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Byte, default: java.lang.Byte): java.lang.Byte = macro qMarkImplDefault[java.lang.Byte]
+
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
 	  *	and adds explicit null-checks to avoid that.
@@ -30,6 +41,17 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Short): java.lang.Short = macro qMarkImpl[java.lang.Short]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Short, default: java.lang.Short): java.lang.Short = macro qMarkImplDefault[java.lang.Short]
+
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
 	  *	and adds explicit null-checks to avoid that.
@@ -39,6 +61,17 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Char): java.lang.Character = macro qMarkImpl[java.lang.Character]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Char, default: java.lang.Character): java.lang.Character = macro qMarkImplDefault[java.lang.Character]
+
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
 	  *	and adds explicit null-checks to avoid that.
@@ -48,6 +81,17 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Int): java.lang.Integer = macro qMarkImpl[java.lang.Integer]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Int, default: java.lang.Integer): java.lang.Integer = macro qMarkImplDefault[java.lang.Integer]
+
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
 	  *	and adds explicit null-checks to avoid that.
@@ -57,6 +101,17 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Long): java.lang.Long = macro qMarkImpl[java.lang.Long]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Long, default: java.lang.Long): java.lang.Long = macro qMarkImplDefault[java.lang.Long]
+
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
 	  *	and adds explicit null-checks to avoid that.
@@ -66,6 +121,16 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Float): java.lang.Float = macro qMarkImpl[java.lang.Float]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Float, default: java.lang.Float): java.lang.Float = macro qMarkImplDefault[java.lang.Float]
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
 	  *	and adds explicit null-checks to avoid that.
@@ -75,6 +140,17 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Double): java.lang.Double = macro qMarkImpl[java.lang.Double]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Double, default: java.lang.Double): java.lang.Double = macro qMarkImplDefault[java.lang.Double]
+
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
 	  *	and adds explicit null-checks to avoid that.
@@ -84,7 +160,16 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Boolean): java.lang.Boolean = macro qMarkImpl[java.lang.Boolean]
-
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Boolean, default: java.lang.Boolean): java.lang.Boolean = macro qMarkImplDefault[java.lang.Boolean]
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
 	  *	and adds explicit null-checks to avoid that.
@@ -95,6 +180,16 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?[A <: AnyRef](expr: A): A = macro qMarkImpl[A]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?[A <: AnyRef](expr: A, default: A): A = macro qMarkImplDefault[A]
 
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
@@ -105,6 +200,16 @@ package object nullsafe {
 	  *         access on `null`, returns null instead.
 	  */
 	def ?(expr: Unit): Unit = macro qMarkUnitImpl[Unit]
+	/**
+	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
+	  *	and adds explicit null-checks to avoid that.
+	  *
+	  * @param expr Some expression that might cause a NullPointerExpression due to method/field access on `null`
+	  * @param default Custom default value to return in the case where NPE would have occurred.
+	  * @return The value of the expression. If there would have been a NullPointerException due to method/field
+	  *         access on `null`, returns `default` instead.
+	  */
+	def ?(expr: Unit, default: Unit): Unit = macro qMarkImplDefault[Unit]
 
 	/**
 	  *	Translates an expression that could cause a NullPointerException due to method/field access on `null`
@@ -130,6 +235,7 @@ package object nullsafe {
 
 	//Putting the implementations in an object to avoid namespace pollution.
 	private[this] object MacroImplementations {
+
 		def qMarkImpl[A : c.WeakTypeTag](c: blackbox.Context)(expr: c.Expr[A]): c.Expr[A] = {
 			import c.universe._
 
@@ -138,6 +244,12 @@ package object nullsafe {
 			c.Expr(result)
 		}
 
+		def qMarkImplDefault[A : c.WeakTypeTag](c: blackbox.Context)(expr: c.Expr[A], default: c.Expr[A]): c.Expr[A] = {
+			val tree = expr.tree
+			val result = rewriteToNullSafe(c)(tree)(default.tree,a => a)
+			c.Expr(result)
+		}
+
 		def qMarkUnitImpl[A : c.WeakTypeTag](c: blackbox.Context)(expr: c.Expr[A]): c.Expr[A] = {
 			import c.universe._
 

src/test/scala/com/ryanstull/nullsafe/Tests.scala

@@ -173,11 +173,69 @@ class Tests extends FlatSpec {
 
 		assert(!notNull(a.b.c.d.e))
 	}
+
+	"Using custom default" should "work for absent case" in {
+		val a = A(B(null))
+
+		assert(?(a.b.c.d.e.s,"") == "")
+	}
+
+	"Using custom default" should "work for present case" in {
+		val a = A(B(C(D(E("Hello")))))
+
+		assert(?(a.b.c.d.e.s,"") == "Hello")
+	}
+
+	"Using custom default" should "work for absent case with Int" in {
+		val a = A(B(null))
+
+		assert(?(a.b.c.d.getInt,new Integer(3)) == 3)
+	}
+
+	"Using custom default" should "work for present case with Int" in {
+		val a = A(B(C(D(E("Hello")))))
+
+		assert(?(a.b.c.d.getInt,new Integer(3)) == 0)
+	}
+
+	"Using custom default" should "work for absent case with Boolean" in {
+		val a = A(B(null))
+
+		assert(?(a.b.c.d.e.getBool,true) == true)
+	}
+
+	"Using custom default" should "work for present case with Boolean" in {
+		val a = A(B(C(D(E("Hello")))))
+
+		assert(?(a.b.c.d.e.getBool,true) == false)
+	}
+
+	"Using custom default" should "work for absent case with Double" in {
+		val a = A(B(null))
+
+		assert(?(a.b.c.d.e.getDouble,3.0) == 3.0)
+	}
+
+	"Using custom default" should "work for present case with Double" in {
+		val a = A(B(C(D(E("Hello")))))
+
+		assert(?(a.b.c.d.e.getDouble,3.0) == 0.0)
+	}
+
+	"Using custom default" should "work for absent case with Unit" in {
+		val a = A(B(null))
+
+		?(a.b.c.d.e.s.notify(),println("Absent"))
+	}
+
 }
 
 //Example of deeply nested domain object
 object Tests {
-	case class E(s: String)
+	case class E(s: String){
+		def getBool: Boolean = false
+		def getDouble: Double = 0.0
+	}
 	case class D(e: E){
 		def getE: E = E(null)
 		def getInt: Int = 0