test for @ syntax

core/src/test/scala/com/github/dmytromitin/SyntaxMonoidSemigroupTest.scala

@@ -0,0 +1,47 @@
+package com.github.dmytromitin
+
+import org.scalatest._
+
+class SyntaxMonoidSemigroupTest extends FlatSpec with Matchers {
+  @syntax
+  trait Semigroup[A] {
+    def combine(a: A, a1: A): A
+  }
+
+  object Semigroup {
+//    object syntax {
+//      implicit class Ops[A](a: A) {
+//        def combine(a1: A)(implicit inst: Semigroup[A]): A = inst.combine(a, a1)
+//      }
+//    }
+  }
+
+  @syntax
+  trait Monoid[A] extends Semigroup[A] {
+    def empty: A
+    def combine(a: A, a1: A): A
+  }
+
+  object Monoid {
+    def instance[A](f: => A, f1: (A, A) => A): Monoid[A] = new Monoid[A] {
+      override def empty: A = f
+      override def combine(a: A, a1: A): A = f1(a, a1)
+    }
+
+//    object syntax {
+//      implicit class Ops[A](a: A) {
+//        def combine(a1: A)(implicit inst: Monoid[A]): A = inst.combine(a, a1)
+//      }
+//    }
+
+    implicit val int: Monoid[Int] = instance(0, _ + _)
+    implicit val str: Monoid[String] = instance("", _ + _)
+  }
+
+  import Semigroup.syntax._
+
+  "2 + 3" should "be 5" in {
+    2.combine(3)(Monoid.int) should be (5)
+  }
+
+}