Rego negation question

common.rego

package common

# ---------------------------------------------------------------------------------------------------------------------
# Not Working
# ---------------------------------------------------------------------------------------------------------------------


list_should_not_contain(attributes_list, undesired_item) {
	list_item = attributes_list[_]
	list_item != undesired_item
}

# ---------------------------------------------------------------------------------------------------------------------
# Working
# ---------------------------------------------------------------------------------------------------------------------

### These ones are working ### 
# Determines if a dict/hash contains a key

list_should_contain(attributes_list, desired_item) {
	list_item = attributes_list[_]
	list_item == desired_item
}

common_test.rego

package commmon

# ---------------------------------------------------------------------------------------------------------------------
# Not working
# ---------------------------------------------------------------------------------------------------------------------

# list_should_not_contain

test_list_should_not_contain {
  attributes_list = [
    "marshall",
    "mathers",
    "haley",
    "kim"
  ]
  undesired_item := "jayz"
  list_should_not_contain(attributes_list, undesired_item)
}

test_list_should_not_contain_fail {
  attributes_list = [
    "marshall",
    "mathers",
    "haley",
    "kim"
  ]
  undesired_item := "marshall"
  not list_should_not_contain(attributes_list, undesired_item)
}


# ---------------------------------------------------------------------------------------------------------------------
# Working
# ---------------------------------------------------------------------------------------------------------------------

# list_should_contain
test_list_should_contain {
  attributes_list = [
    "marshall",
    "mathers",
    "haley",
    "kim"
  ]
  desired_item := "marshall"
  list_should_contain(attributes_list, desired_item)
}

test_list_should_contain_fail {
  attributes_list = [
    "marshall",
    "mathers",
    "haley",
    "kim"
  ]
  desired_item := "jayz"
  not list_should_contain(attributes_list, desired_item)
}

negation-question-rego.md

Hi,

I think I'm having an issue with double negation in Rego. Can I get some help on this?

Output of opa test -v . --explain fails

FAILURES
--------------------------------------------------------------------------------
data.common.test_list_should_not_contain_fail: FAIL (369.077µs)

  Enter data.common.test_list_should_not_contain_fail = _
  | Enter data.common.test_list_should_not_contain_fail
  | | Enter data.common.list_should_not_contain(attributes_list, __local13__)
  | | | Enter data.common.list_should_not_contain
  | | | | Fail neq(list_item, undesired_item)
  | | Fail not data.common.list_should_not_contain(attributes_list, __local13__)
  | Fail data.common.test_list_should_not_contain_fail = _

SUMMARY
--------------------------------------------------------------------------------
data.common.test_should_not_equal: PASS (638.863µs)
data.common.test_should_not_equal_fail: PASS (314.325µs)
data.common.test_should_equal: PASS (283.209µs)
data.common.test_should_equal_fail: PASS (286.037µs)
data.common.test_should_have_property: PASS (292.273µs)
data.common.test_should_have_property_fail: PASS (359.747µs)
data.common.test_list_should_contain: PASS (327.73µs)
data.common.test_list_should_contain_fail: PASS (331.304µs)
data.common.test_list_should_not_contain: PASS (383.242µs)
data.common.test_list_should_not_contain_fail: FAIL (369.077µs)
--------------------------------------------------------------------------------
PASS: 9/10
FAIL: 1/10