Scala test matcher to compare jsons

JsonEqualityMatcher.scala

import org.scalactic.Prettifier
import org.scalatest.matchers.{MatchResult, Matcher}
import org.scalatest.{FunSpec, Matchers}
import org.skyscreamer.jsonassert.{JSONCompare, JSONCompareMode}

trait JsonEqualityMatcher {

  def equalsToJson(spread: String): Matcher[String] = {
    new Matcher[String] {
      def apply(left: String): MatchResult = {
        val result = JSONCompare.compareJSON(left, spread, JSONCompareMode.STRICT)
        MatchResult(
          !result.failed(),
          "json are not equals",
          result.getMessage
        )
      }
      override def toString: String = "jsonEqual (" + Prettifier.default(spread) + ")"
    }
  }

}

class JsonEqualityMatcherSpec extends FunSpec with Matchers with JsonEqualityMatcher {

  describe("equalsToJson matcher") {

    val jsonA =
      """{
        |"a": "a",
        |"b": {
        |  "c": "123", "d": "abc"
        |}
        |}""".stripMargin

    describe("for two json strings if they are structurally equals") {

      val jsonB =
        """{"a": "a", "b": {
          |"c": "123",
          |"d": "abc"}
          |}""".stripMargin


      it("should return a positive a matching") {
        jsonA should equalsToJson(jsonB)
      }

    }

    describe("for two json strings that are not structurally equals") {

      val jsonC =
        """{"b": "4444", "z": {
          |"j": "123",
          |"d": "abc"}
          |}""".stripMargin


      it("should return a positive a matching") {
        jsonA should not(equalsToJson(jsonC))
      }

    }

  }

}