Play Framework/Scala example source code file (JsonTransSpec.scala)

This example Play Framework source code file (JsonTransSpec.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Play Framework (and Scala) source code examples by using tags.

All credit for the original source code belongs to Play Framework; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Play Framework tags/keywords

api, jserror, jsnumber, jsobjects, json, jsontransspec, jsstring, lib, library, play, play framework, seq, specification, validation

The JsonTransSpec.scala Play Framework example source code

/*
 * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
 */
package play.api.libs.json

import org.specs2.mutable._
import play.api.libs.json._
import play.api.libs.json.Json._
import scala.util.control.Exception._
import java.text.ParseException
import play.api.data.validation.ValidationError
import Reads.constraints._
import play.api.libs.json.util._
import play.api.libs.json.Reads._
import play.api.libs.functional.syntax._


object JsonTransSpec extends Specification {
  "JSON transformers " should {
    val js = Json.obj(
      "field1" -> "alpha",
      "field2" -> 123L,
      "field3" -> Json.obj(
        "field31" -> "beta",
        "field32"-> 345
      ),
      "field4" -> Json.arr("alpha", 2, true, Json.obj("field41" -> "toto", "field42" -> "tata"))
    )

    "pick a value at a path" in {
      js.transform(
        (__ \ 'field3).json.pick
      ).get must beEqualTo(
        Json.obj(
          "field31" -> "beta", "field32"-> 345
        )
      )
    }

    "pick a branch" in {
      js.transform(
        (__ \ 'field3).json.pickBranch
      ).get must beEqualTo(
        Json.obj(
          "field3" -> Json.obj("field31" -> "beta", "field32"-> 345)
        )
      )
    }

    "copy input JSON and update a branch (merge the updated branch with input JSON)" in {
      js.transform(
        (__ \ 'field3).json.update(
          __.read[JsObject].map{ o => o ++ Json.obj( "field33" -> false ) }
        )
      ).get must beEqualTo(
        Json.obj(
          "field1" -> "alpha",
          "field2" -> 123L,
          "field3" -> Json.obj(
            "field31" -> "beta",
            "field32" -> 345,
            "field33" -> false
          ),
          "field4" -> Json.arr("alpha", 2, true, Json.obj("field41" -> "toto", "field42" -> "tata"))
        )
      )
    }

    "pick a branch and update its content" in {
      js.transform(
        (__ \ 'field3).json.pickBranch(
          (__ \ 'field32).json.update(
            Reads.of[JsNumber].map{ case JsNumber(nb) => JsNumber(nb + 12) }
          ) andThen
          (__ \ 'field31).json.update(
            Reads.of[JsString].map{ case JsString(s) => JsString(s + "toto") }
          )
        )
      ).get must beEqualTo(
        Json.obj(
          "field3" -> Json.obj("field31" -> "betatoto", "field32"-> 357)
        )
      )
    }

    "put a value in a new branch (don't keep passed json)" in {
      js.transform(
        (__ \ 'field3).json.put(JsNumber(234))
      ).get must beEqualTo(
        Json.obj(
          "field3" -> 234
        )
      )
    }

    "create a new path by copying a branch" in {
      js.transform(
        (__ \ 'field5).json.copyFrom( (__ \ 'field3).json.pick )
      ).get must beEqualTo(
        Json.obj(
          "field5" -> Json.obj(
            "field31" -> "beta",
            "field32" -> 345
          )
        )
      )
    }

    "copy full json and prune a branch" in {
      js.transform(
        (__ \ 'field3).json.prune
      ).get must beEqualTo(
        Json.obj(
          "field1" -> "alpha",
          "field2" -> 123L,
          "field4" -> Json.arr("alpha", 2, true, Json.obj("field41" -> "toto", "field42" -> "tata"))
        )
      )
    }

    "pick a single branch and prune a sub-branch" in {
      js.transform(
        (__ \ 'field3).json.pickBranch(
          (__ \ 'field32).json.prune
        )
      ).get must beEqualTo(
        Json.obj(
          "field3" -> Json.obj("field31" -> "beta")
        )
      )
    }

    "copy the full json and update a 2nd-level path and then prune a subbranch" in {
      js.validate(
        (__ \ 'field3 \ 'field32).json.update(
          Reads.of[JsNumber].map{ case JsNumber(nb) => JsNumber(nb + 5) }
        ) andThen (__ \ 'field4).json.prune
      ).get must beEqualTo(
        Json.obj(
          "field1" -> "alpha",
          "field2" -> 123L,
          "field3" -> Json.obj(
            "field31" -> "beta",
            "field32"-> 350
          )
        )
      )
    }

    "deepMerge when reducing JsObjects" in {
      val json = Json.obj("somekey1" -> 11, "somekey2" -> 22)
      val jsonTransform = (
        (__ \ "key1" \ "sk1").json.copyFrom((__ \ "somekey1").json.pick)
        and
        (__ \ "key1" \ "sk2").json.copyFrom((__ \ "somekey2").json.pick)
      ).reduce

      json.validate(jsonTransform).get must beEqualTo(
        Json.obj("key1" -> Json.obj("sk1" -> 11, "sk2" -> 22))
      )
    }

    "report the correct path in the JsError" in {
      "when the field to modify doesn't exist" in {
        js.transform(
          (__ \ 'field42).json.update(__.read[JsString])
        ).asEither.left.get.head must_== (__ \ 'field42, Seq(ValidationError("error.path.missing")))
      }

      "when the reader is the wrong type" in {
        js.transform(
          (__ \ 'field2).json.update(__.read[JsString])
        ).asEither.left.get.head must_== (__ \ 'field2, Seq(ValidationError("error.expected.jsstring")))
      }
    }
  }
}