Pageable.size returns 0 for non-empty Page queried from JpaRepository with Pageable.unpaged()

Versions: Spring Boot version: 2.1.2.RELEASE Kotlin version: 1.3.21 I am using Envers via data-spring-envers. (I don’t think Envers makes any changes to how Paging works, but I mention it just to be complete.)

Hello, I don’t know if this is the right place to fill this issue and I couldn’t find anything similar in the existing ones. The problem is: Calling size (inherited from Slice) on Page<T> instance will always return 0, even if the page has items.

The following test code will trigger an assert:

// (code from working project, but reduced to make smaller test case)
// repository
// src/main/kotlin/example/repositories/LocationRepository.kt
package example.repositories

import example.entities.Location
import org.springframework.data.domain.Page
import org.springframework.data.domain.Pageable
import org.springframework.data.jpa.repository.JpaRepository
import org.springframework.data.jpa.repository.JpaSpecificationExecutor
import org.springframework.data.repository.history.RevisionRepository

interface LocationRepository : JpaRepository<Location, Long>, JpaSpecificationExecutor<Location>, RevisionRepository<Location, Long, Int> {
    fun findByCodeIgnoreCaseContaining(code: String, paging: Pageable): Page<Location>
}

// entity
// src/main/kotlin/example/entities/Location.kt
package example.entities

import org.hibernate.envers.Audited
import org.hibernate.envers.RelationTargetAuditMode
import javax.persistence.*

@Entity
@Table(name = "location")
@Audited
class Location {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    var id: Long? = null

    @Column(name = "code")
    var code: String = ""
    // ...
}

// test
// src/test/kotlin/example/specifications/LocationSpecificationTest.kt
package example.specifications

import example.config.JpaEnversConfiguration
import example.config.PaginationConfig
import example.config.repositories.LocationRepository
import example.utils.SearchCriteria
import org.hibernate.envers.AuditOverride
import org.junit.Test

import org.junit.Assert.*
import org.junit.runner.RunWith
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest
import org.springframework.context.annotation.Import
import org.springframework.data.domain.Pageable
import org.springframework.test.context.ActiveProfiles
import org.springframework.test.context.junit4.SpringRunner

@RunWith(SpringRunner::class)
@ActiveProfiles("test")
@DataJpaTest
@Import(JpaEnversConfiguration::class)
class LocationSpecificationTest {
    @Autowired
    lateinit var locationRepository: LocationRepository

    @Test
    fun sanityCheckForLocationsNonExisting() {
        val locations = locationRepository.findByCodeIgnoreCaseContaining("NONEXISTING", Pageable.unpaged())
        println("locations.size == 0: ${locations.size == 0}")
        println(locations)
        locations.forEach {
            println(it)
        }
        assertTrue(locations.isEmpty)
        assertTrue(locations.totalElements == 0.toLong())
        assertTrue(locations.size == 0) // this is OK
        assertTrue(locations.totalElements == locations.size.toLong())
    }

    @Test
    fun sanityCheckForLocationsExisting() {
        val locations = locationRepository.findByCodeIgnoreCaseContaining("L", Pageable.unpaged())
        println("locations.size == 0: ${locations.size == 0}")
        println(locations)
        locations.forEach {
            println(it)
        }
        assertFalse(locations.isEmpty)
        assertFalse(locations.totalElements == 0.toLong())
        // vvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
        assertFalse(locations.size == 0) // <<<---- THIS LINE FAILS
        // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        assertTrue(locations.totalElements == locations.size.toLong())
    }
}

// others
// src/main/kotlin/example/config/JpaEnversConfiguration.kt
package example.config

import org.springframework.context.annotation.Configuration
import org.springframework.data.envers.repository.support.EnversRevisionRepositoryFactoryBean
import org.springframework.data.jpa.repository.config.EnableJpaRepositories

@Configuration
@EnableJpaRepositories(basePackages = ["example"], repositoryFactoryBeanClass = EnversRevisionRepositoryFactoryBean::class)
class JpaEnversConfiguration

Result: sanityCheckForLocationsNonExisting: passed sanityCheckForLocationsExisting: assertion error.

locations.size == 0: true
Page 1 of 1 containing example.entities.Location instances
#<Location:87682515, id: 1, code: "L">

java.lang.AssertionError
at org.junit.Assert.fail(Assert.java:86)
at org.junit.Assert.assertTrue(Assert.java:41)
at org.junit.Assert.assertFalse(Assert.java:64)
at org.junit.Assert.assertFalse(Assert.java:74)
at example.specifications.LocationSpecificationTest.sanityCheckForLocationsExisting(LocationSpecificationTest.kt:53)
*/

[daliborfilus]

Yes, I understand that, but this definitely looked like a bug. If I had doubts about that, I would ask on SO. But if you say this is not a bug, even if it walks, talks and acts like a bug, but an intended behavior, then I’m fine with that.

[wilkinsona]

Spring Data issues are tracked using JIRA. Issues for Spring Data Commons, where the paging logic resides, are here. That said, an issue isn’t really the right place to raise something that you don’t understand. Stack Overflow or Gitter (there’s a Spring Data room) are both better places.