Spring Mongo Typed Queries Experiment

TypedQueriesTest.kt

package com.github.tjeukayim

import org.bson.types.ObjectId
import org.junit.jupiter.api.Assertions.assertEquals
import org.junit.jupiter.api.Test
import org.springframework.data.mongodb.core.mapping.Document
import org.springframework.data.mongodb.core.query.Criteria
import org.springframework.data.mongodb.core.query.CriteriaDefinition
import org.springframework.data.mongodb.core.query.isEqualTo
import kotlin.reflect.KProperty

class TypedQueriesTest {
  @Test
  fun `Typed query gt and isEqualTo`() {
    val classic = Criteria("price").gt(1100)
      .and("available").isEqualTo(true)

    val typed = typedCriteria {
      Book::price gt 1100
      Book::available isEqualTo true
    }

    assertEquals(classic, typed)
  }
}

@Document("books")
data class Book(
  val id: ObjectId,
  val name: String,
  val price: Int,
  val available: Boolean
)

fun typedCriteria(block: TypedCriteria.() -> Unit): CriteriaDefinition {
  val builder = TypedCriteria()
  builder.block()
  return builder.chain
}

class TypedCriteria {
  var chain = Criteria()

  infix fun <T : Any> KProperty<T>.gt(value: T) {
    chain = chain.and(name).gt(value)
  }

  infix fun <T : Any> KProperty<T>.isEqualTo(value: T) {
    chain = chain.and(name).isEqualTo(value)
  }
}