More convenient operations for JSONValues (#1123)

* More convenient operations for JSONValues

* Add test cases

airframe-json/src/main/scala/wvlet/airframe/json/package.scala

@@ -62,6 +62,36 @@ package object json {
         case JSONObject(x)  => x.map(x => (x._1, x._2.value)).toMap
       }
     }
+
+    def isNull: Boolean = {
+      jsonValue == JSONNull
+    }
+
+    def toStringValue: String = {
+      jsonValue.asInstanceOf[JSONString].v
+    }
+    def toDoubleValue: Double = {
+      jsonValue.asInstanceOf[JSONDouble].v
+    }
+    def toLongValue: Long = {
+      jsonValue.asInstanceOf[JSONLong].v
+    }
+    def toBooleanValue: Boolean = {
+      jsonValue.asInstanceOf[JSONBoolean].v
+    }
+    def toArrayValue: IndexedSeq[JSONValue] = {
+      jsonValue.asInstanceOf[JSONArray].v
+    }
+    def toObjectValue: Map[String, JSONValue] = {
+      jsonValue.asInstanceOf[JSONObject].v.toMap
+    }
+
+    def apply(name: String): JSONValue = {
+      jsonValue.asInstanceOf[JSONObject].get(name).get
+    }
+    def apply(i: Int): JSONValue = {
+      jsonValue.asInstanceOf[JSONArray].v(i)
+    }
   }
 
   implicit class JSONValueSeqOps(val jsonValues: Seq[JSONValue]) extends AnyVal {
@@ -76,5 +106,50 @@ package object json {
     def value: Any = {
       jsonValues.head.value
     }
+
+    def toStringValues: Seq[String] = {
+      jsonValues.map(_.asInstanceOf[JSONString].v)
+    }
+    def toDoubleValues: Seq[Double] = {
+      jsonValues.map(_.asInstanceOf[JSONDouble].v)
+    }
+    def toLongValues: Seq[Long] = {
+      jsonValues.map(_.asInstanceOf[JSONLong].v)
+    }
+    def toBooleanValues: Seq[Boolean] = {
+      jsonValues.map(_.asInstanceOf[JSONBoolean].v)
+    }
+    def toArrayValues: Seq[IndexedSeq[JSONValue]] = {
+      jsonValues.map(_.asInstanceOf[JSONArray].v)
+    }
+    def toObjectValues: Seq[Map[String, JSONValue]] = {
+      jsonValues.map(_.asInstanceOf[JSONObject].v.toMap)
+    }
+
+    def toStringValue: String = {
+      jsonValues.head.asInstanceOf[JSONString].v
+    }
+    def toDoubleValue: Double = {
+      jsonValues.head.asInstanceOf[JSONDouble].v
+    }
+    def toLongValue: Long = {
+      jsonValues.head.asInstanceOf[JSONLong].v
+    }
+    def toBooleanValue: Boolean = {
+      jsonValues.head.asInstanceOf[JSONBoolean].v
+    }
+    def toArrayValue: IndexedSeq[JSONValue] = {
+      jsonValues.head.asInstanceOf[JSONArray].v
+    }
+    def toObjectValue: Map[String, JSONValue] = {
+      jsonValues.head.asInstanceOf[JSONObject].v.toMap
+    }
+
+    def apply(name: String): JSONValue = {
+      jsonValues.head.asInstanceOf[JSONObject].get(name).get
+    }
+    def apply(i: Int): JSONValue = {
+      jsonValues.head.asInstanceOf[JSONArray].v(i)
+    }
   }
 }

airframe-json/src/test/scala/wvlet/airframe/json/JSONTest.scala

@@ -12,7 +12,7 @@
  * limitations under the License.
  */
 package wvlet.airframe.json
-import wvlet.airframe.json.JSON.{JSONArray, JSONLong, JSONNumber, JSONObject}
+import wvlet.airframe.json.JSON._
 import wvlet.airspec.AirSpec
 
 /**
@@ -40,16 +40,43 @@ class JSONTest extends AirSpec {
   }
 
   def `JSON DSL`: Unit = {
-    val json: Json = """{"user": [{ "id": 1, "name": "a" }, { "id": 2, "name": "b" }]}"""
+    val json: Json = """{"user": [{ "id": 1, "name": "a", "flag": true }, { "id": 2, "name": "b", "flag": null }]}"""
     val jsonValue  = JSON.parse(json)
 
-    val id = (jsonValue / "user" / "id")(0).value
-    id shouldBe 1
+    val ids = (jsonValue / "user" / "id").values
+    ids shouldBe Seq(1, 2)
 
-    val name = (jsonValue / "user" / "name")(1).value
-    name shouldBe "b"
+    val id1 = (jsonValue / "user" / "id")(0).value
+    id1 shouldBe 1
 
-    val users = (jsonValue / "user").value
-    users shouldBe Seq(Map("id" -> 1, "name" -> "a"), Map("id" -> 2, "name" -> "b"))
+    val id2 = jsonValue("user")(1)("id").toLongValue
+    id2 shouldBe 2
+
+    val name1 = jsonValue("user")(0)("name").toStringValue
+    name1 shouldBe "a"
+
+    val name2 = (jsonValue / "user" / "name")(1).value
+    name2 shouldBe "b"
+
+    val flag1 = jsonValue("user")(0)("flag").toBooleanValue
+    flag1 shouldBe true
+
+    val flag2 = jsonValue("user")(1)("flag")
+    flag2.isNull shouldBe true
+
+    val users1 = (jsonValue / "user").value
+    users1 shouldBe Seq(Map("id" -> 1, "name" -> "a", "flag" -> true), Map("id" -> 2, "name" -> "b", "flag" -> null))
+
+    val users2 = (jsonValue / "user").toArrayValue
+    users2.length shouldBe 2
+    users2(0).toObjectValue shouldBe Map("id" -> JSONLong(1), "name" -> JSONString("a"), "flag" -> JSONBoolean(true))
+    users2(1).toObjectValue shouldBe Map("id" -> JSONLong(2), "name" -> JSONString("b"), "flag" -> JSONNull)
+  }
+
+  def `Extract nested properties by JSON DSL`: Unit = {
+    val json: Json = """{"user": [{ "values": {"value": "a"} }, { "values": {"value": "b"} }]}"""
+    val values     = JSON.parse(json) / "user" / "values" / "value"
+
+    values.map(_.toStringValue) shouldBe Seq("a", "b")
   }
 }