GRAILS-8815: Domain hasMany association using a List is adding duplicate items when the parent is saved

[graemerocher]

Original Reporter: tednaleid
Environment: mac osx grails 2.0.1
Version: 2.0.1
Migrated From: http://jira.grails.org/browse/GRAILS-8815

If you have an Author that has a List of Book objects:

doublesave.Author:
{code}

package doublesave

class Author {
String firstName
String lastName

// Hi, see here! 
List books

static hasMany = [books: Book]

}
{code}

doublesave.Book:
{code}
package doublesave

class Book {
String title
Date published
BigDecimal price

static belongsTo = [author: Author]

}
{code}

It will re-add a book to the list whenever the Author is saved:

{code}

package doublesave

import grails.test.mixin.*
import org.junit.*

@testfor(Author)
class AuthorTests {

void testSomething() {
    def author = new Author(firstName:'foo', lastName: 'bar')
    author.save()
    assert author.id != null
    assert author.books == null

    def book1 = new Book(title: 'grails', price: 43, published: new Date(), author: author)
    assert author.books == null

    // add the book to the author to complete the other side
    author.addToBooks(book1)
    assert author.books.size() == 1

    author.save()
    // WTF!  Books size is 2 after the author save?!?
    assert author.books.size() == 1

}
}
{code}

The same test fails in unit and integration tests in 2.0.1.

[graemerocher]

graemerocher said:
Well, this is not really a bug, because Grails will automatically link the association, and List allows duplicates.. not sure at this stage

[graemerocher]

graemerocher said:
fixed by spring-attic/grails-data-mapping@48b9f6d