Scala Macro for Custom Entity Comparison

This gist contains a Scala 3 macro that compares two entities field by field, automatically skipping any fields where exactly one of the values is null. The comparison logic is generated at compile time using Scala's quoted API, which ensures no runtime reflection overhead.

Features

• Compare two entities of any type.
• Skip fields with null values based on predefined business rules.
• Avoid runtime reflection by generating code at compile time.

Example

The example compares two Address objects:

@main def main(): Unit = {
  val testCases = List(
    (("USA", null, "New York"), ("USA", "NY", null)),                  // true
    ((null, null, null), (null, null, null)),                          // true
    (("USA", null, null), ("USA", null, null)),                        // true
    (("Germany", "Berlin", "Berlin"), ("Germany", "Berlin", null)),    // true
    (("France", "Paris", "Lyon"), ("France", "Paris", "Lyon")),        // true
    (("Canada", null, "Toronto"), ("Canada", "Ontario", "Toronto")),   // true
    ((null, "California", null), (null, "California", "Los Angeles")), // true
    (("Italy", "Rome", null), ("Italy", null, "Rome")),                // true
    (("Japan", "Tokyo", "Shibuya"), ("Japan", "Kyoto", "Osaka")),      // false
    (("Poland", null, "New York"), ("USA", "NY", null)),               // false
  )

  testCases.foreach { case (a, b) =>
    val addrA = Address(a._1, a._2, a._3)
    val addrB = Address(b._1, b._2, b._3)
    println(compareEntity(addrA, addrB))
  }
}

case class Address(country: String, state: String, city: String)