atk4\data\tests\ReferenceSQLTest::testReferenceHook PHP Method

    public function testReferenceHook()
    {
        $a = ['user' => [['name' => 'John', 'contact_id' => 2], ['name' => 'Peter', 'contact_id' => null], ['name' => 'Joe', 'contact_id' => 3]], 'contact' => [['address' => 'Sue contact'], ['address' => 'John contact'], ['address' => 'Joe contact']]];
        $this->setDB($a);
        $db = new Persistence_SQL($this->db->connection);
        $u = (new Model($db, 'user'))->addFields(['name']);
        $c = (new Model($db, 'contact'))->addFields(['address']);
        $u->hasOne('contact_id', $c)->addField('address');
        $u->load(1);
        $this->assertEquals('John contact', $u['address']);
        $this->assertEquals('John contact', $u->ref('contact_id')['address']);
        $u->load(2);
        $this->assertEquals(null, $u['address']);
        $this->assertEquals(null, $u['contact_id']);
        $this->assertEquals(null, $u->ref('contact_id')['address']);
        $u->load(3);
        $this->assertEquals('Joe contact', $u['address']);
        $this->assertEquals('Joe contact', $u->ref('contact_id')['address']);
        $u->load(2);
        $u->ref('contact_id')->save(['address' => 'Peters new contact']);
        $this->assertNotEquals(null, $u['contact_id']);
        $this->assertEquals('Peters new contact', $u->ref('contact_id')['address']);
        $u->save()->reload();
        $this->assertEquals('Peters new contact', $u->ref('contact_id')['address']);
        $this->assertEquals('Peters new contact', $u['address']);
    }