org.scalactic.source.ObjectMeta.scala Maven / Gradle / Ivy

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/*
 * Copyright 2001-2016 Artima, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.scalactic.source

trait ObjectMeta {

  def fieldNames: scala.collection.immutable.IndexedSeq[String]

  def hasField(name: String): Boolean = fieldNames.contains(name)

  def value(name: String): Any

  def typeName(name: String): String

  def shortTypeName(name: String): String

}

object ObjectMeta {

  def objectMetaUsingJavaReflection(v: Any): ObjectMeta =
    new ObjectMeta {
      lazy val privFields = v.getClass.getDeclaredFields.filter(!_.isAccessible).map(_.getName)

      lazy val fieldNames = {
        v.getClass.getDeclaredMethods.filter { m =>
          // SKIP-DOTTY-START
          m.getParameterTypes.isEmpty && privFields.contains(m.getName)
          // SKIP-DOTTY-END
          //DOTTY-ONLY m.getParameterTypes.isEmpty && privFields.contains(m.getName) && m.getName != "$outer"
        }.map { f =>
          if (f.getName.endsWith("$mcI$sp"))
            f.getName.dropRight(7)
          else
            f.getName
        }.toVector
      }

      def value(name: String): Any =
        try {
          v.getClass.getDeclaredMethod(name).invoke(v)
        }
        catch {
          case e: NoSuchMethodException =>
            try {
              v.getClass.getDeclaredMethod(name + "$mcI$sp").invoke(v)
            }
            catch {
              case e: NoSuchMethodException =>
                throw new IllegalArgumentException("'" + name + "' is not attribute for this instance.")
            }
        }

      def typeName(name: String): String = value(name).getClass.getName

      def shortTypeName(name: String): String = value(name).getClass.getSimpleName
    }

  def apply(v: Any): ObjectMeta = objectMetaUsingJavaReflection(v)

}