+is($assembly_part->part_type, 'assembly', 'assembly has correct type');
+is( scalar @{$assembly_part->assemblies}, 3, 'assembly consists of three parts' );
+
+# fetch assembly item corresponding to partnumber 19000
+my $assembly_items = $assembly_part->find_assemblies( { parts_id => $assembly_item_part->id } ) || die "can't find assembly_item";
+my $assembly_item = $assembly_items->[0];
+is($assembly_item->part->partnumber, '19000 1', 'assembly part part relation works');
+is($assembly_item->assembly_part->partnumber, '19000', 'assembly part assembly part relation works');
+
+
+
+my $assembly2_part = new_assembly( partnumber => '20000', assnumber => 'as2' )->save;
+my $retval = validate_assembly($assembly_part,$assembly2_part);
+ok(!defined $retval, 'assembly 19000 can be child of assembly 20000' );
+$assembly2_part->add_assemblies(SL::DB::Assembly->new(parts_id => $assembly_part->id, qty => 3, bom => 1));
+$assembly2_part->save;
+
+my $assembly3_part = new_assembly( partnumber => '30000', assnumber => 'as3' )->save;
+$retval = validate_assembly($assembly3_part,$assembly_part);
+ok(!defined $retval, 'assembly 30000 can be child of assembly 19000' );
+
+$retval = validate_assembly($assembly3_part,$assembly2_part);
+ok(!defined $retval, 'assembly 30000 can be child of assembly 20000' );
+
+$assembly_part->add_assemblies(SL::DB::Assembly->new(parts_id => $assembly3_part->id, qty => 4, bom => 1));
+$assembly_part->save;
+
+$retval = validate_assembly($assembly3_part,$assembly2_part);
+ok(!defined $retval, 'assembly 30000 can be child of assembly 20000' );
+
+$assembly2_part->add_assemblies(SL::DB::Assembly->new(parts_id => $assembly3_part->id, qty => 5, bom => 1));
+$assembly2_part->save;
+
+# fetch assembly item corresponding to partnumber 20000
+my $assembly2_items = $assembly2_part->find_assemblies() || die "can't find assembly_item";
+is( scalar @{$assembly2_items}, 5, 'assembly2 consists of ive parts' );
+my $assembly2_item = $assembly2_items->[3];
+is($assembly2_item->qty, 3, 'qty of 3rd assembly item is 3' );
+is($assembly2_item->part->part_type, 'assembly', '3rd assembly item \'' . $assembly2_item->part->partnumber . '\' is also an assembly');
+my $assembly3_items = $assembly2_item->part->find_assemblies() || die "can't find assembly_item";
+is( scalar @{$assembly3_items}, 4, 'assembly3 consists of four parts' );
+
+
+
+# check loop to itself
+$retval = validate_assembly($assembly_part,$assembly_part);
+is( $retval,"The assembly '19000' cannot be a part from itself.", 'assembly loops to itself' );
+if (!$retval && $assembly_part->add_assemblies( SL::DB::Assembly->new(parts_id => $assembly_part->id, qty => 8, bom => 1))) {
+ $assembly_part->save;
+}
+is( scalar @{$assembly_part->assemblies}, 4, 'assembly consists of four parts' );
+
+# check indirekt loop
+$retval = validate_assembly($assembly2_part,$assembly_part);
+ok( $retval, 'assembly indirect loop' );
+if (!$retval && $assembly_part->add_assemblies( SL::DB::Assembly->new(parts_id => $assembly2_part->id, qty => 9, bom => 1))) {
+ $assembly_part->save;
+}
+is( scalar @{$assembly_part->assemblies}, 4, 'assembly consists of four parts' );