set_test.go

package mapset

import "testing"

func makeSet(ints []int) Set {
	set := NewSet()
	for _, i := range ints {
		set.Add(i)
	}
	return set
}

func makeUnsafeSet(ints []int) Set {
	set := NewUnsafeSet()
	for _, i := range ints {
		set.Add(i)
	}
	return set
}

func assertEqual(a, b Set, t *testing.T) {
	if !a.Equal(b) {
		t.Errorf("%v != %v\n", a, b)
	}
}

func Test_NewSet(t *testing.T) {
	a := NewSet()
	if a.Cardinality() != 0 {
		t.Error("NewSet should start out as an empty set")
	}

	assertEqual(NewSet(), NewSet(), t)
	assertEqual(NewSet(1), NewSet(1), t)
	assertEqual(NewSet(1, 2), NewSet(1, 2), t)
	assertEqual(NewSet("a"), NewSet("a"), t)
	assertEqual(NewSet("a", "b"), NewSet("a", "b"), t)
}

func Test_NewUnsafeSet(t *testing.T) {
	a := NewUnsafeSet()

	if a.Cardinality() != 0 {
		t.Error("NewSet should start out as an empty set")
	}
}

func Test_AddSet(t *testing.T) {
	a := makeSet([]int{1, 2, 3})

	if a.Cardinality() != 3 {
		t.Error("AddSet does not have a size of 3 even though 3 items were added to a new set")
	}
}

func Test_AddUnsafeSet(t *testing.T) {
	a := makeUnsafeSet([]int{1, 2, 3})

	if a.Cardinality() != 3 {
		t.Error("AddSet does not have a size of 3 even though 3 items were added to a new set")
	}
}

func Test_AddSetNoDuplicate(t *testing.T) {
	a := makeSet([]int{7, 5, 3, 7})

	if a.Cardinality() != 3 {
		t.Error("AddSetNoDuplicate set should have 3 elements since 7 is a duplicate")
	}

	if !(a.Contains(7) && a.Contains(5) && a.Contains(3)) {
		t.Error("AddSetNoDuplicate set should have a 7, 5, and 3 in it.")
	}
}

func Test_AddUnsafeSetNoDuplicate(t *testing.T) {
	a := makeUnsafeSet([]int{7, 5, 3, 7})

	if a.Cardinality() != 3 {
		t.Error("AddSetNoDuplicate set should have 3 elements since 7 is a duplicate")
	}

	if !(a.Contains(7) && a.Contains(5) && a.Contains(3)) {
		t.Error("AddSetNoDuplicate set should have a 7, 5, and 3 in it.")
	}
}

func Test_RemoveSet(t *testing.T) {
	a := makeSet([]int{6, 3, 1})

	a.Remove(3)

	if a.Cardinality() != 2 {
		t.Error("RemoveSet should only have 2 items in the set")
	}

	if !(a.Contains(6) && a.Contains(1)) {
		t.Error("RemoveSet should have only items 6 and 1 in the set")
	}

	a.Remove(6)
	a.Remove(1)

	if a.Cardinality() != 0 {
		t.Error("RemoveSet should be an empty set after removing 6 and 1")
	}
}

func Test_RemoveUnsafeSet(t *testing.T) {
	a := makeUnsafeSet([]int{6, 3, 1})

	a.Remove(3)

	if a.Cardinality() != 2 {
		t.Error("RemoveSet should only have 2 items in the set")
	}

	if !(a.Contains(6) && a.Contains(1)) {
		t.Error("RemoveSet should have only items 6 and 1 in the set")
	}

	a.Remove(6)
	a.Remove(1)

	if a.Cardinality() != 0 {
		t.Error("RemoveSet should be an empty set after removing 6 and 1")
	}
}

func Test_ContainsSet(t *testing.T) {
	a := NewSet()

	a.Add(71)

	if !a.Contains(71) {
		t.Error("ContainsSet should contain 71")
	}

	a.Remove(71)

	if a.Contains(71) {
		t.Error("ContainsSet should not contain 71")
	}

	a.Add(13)
	a.Add(7)
	a.Add(1)

	if !(a.Contains(13) && a.Contains(7) && a.Contains(1)) {
		t.Error("ContainsSet should contain 13, 7, 1")
	}
}

func Test_ContainsUnsafeSet(t *testing.T) {
	a := NewUnsafeSet()

	a.Add(71)

	if !a.Contains(71) {
		t.Error("ContainsSet should contain 71")
	}

	a.Remove(71)

	if a.Contains(71) {
		t.Error("ContainsSet should not contain 71")
	}

	a.Add(13)
	a.Add(7)
	a.Add(1)

	if !(a.Contains(13) && a.Contains(7) && a.Contains(1)) {
		t.Error("ContainsSet should contain 13, 7, 1")
	}
}

func Test_ContainsMultipleSet(t *testing.T) {
	a := makeSet([]int{8, 6, 7, 5, 3, 0, 9})

	if !a.Contains(8, 6, 7, 5, 3, 0, 9) {
		t.Error("ContainsAll should contain Jenny's phone number")
	}

	if a.Contains(8, 6, 11, 5, 3, 0, 9) {
		t.Error("ContainsAll should not have all of these numbers")
	}
}

func Test_ContainsMultipleUnsafeSet(t *testing.T) {
	a := makeUnsafeSet([]int{8, 6, 7, 5, 3, 0, 9})

	if !a.Contains(8, 6, 7, 5, 3, 0, 9) {
		t.Error("ContainsAll should contain Jenny's phone number")
	}

	if a.Contains(8, 6, 11, 5, 3, 0, 9) {
		t.Error("ContainsAll should not have all of these numbers")
	}
}

func Test_ClearSet(t *testing.T) {
	a := makeSet([]int{2, 5, 9, 10})

	a.Clear()

	if a.Cardinality() != 0 {
		t.Error("ClearSet should be an empty set")
	}
}

func Test_ClearUnsafeSet(t *testing.T) {
	a := makeUnsafeSet([]int{2, 5, 9, 10})

	a.Clear()

	if a.Cardinality() != 0 {
		t.Error("ClearSet should be an empty set")
	}
}

func Test_CardinalitySet(t *testing.T) {
	a := NewSet()

	if a.Cardinality() != 0 {
		t.Error("set should be an empty set")
	}

	a.Add(1)

	if a.Cardinality() != 1 {
		t.Error("set should have a size of 1")
	}

	a.Remove(1)

	if a.Cardinality() != 0 {
		t.Error("set should be an empty set")
	}

	a.Add(9)

	if a.Cardinality() != 1 {
		t.Error("set should have a size of 1")
	}

	a.Clear()

	if a.Cardinality() != 0 {
		t.Error("set should have a size of 1")
	}
}

func Test_CardinalityUnsafeSet(t *testing.T) {
	a := NewUnsafeSet()

	if a.Cardinality() != 0 {
		t.Error("set should be an empty set")
	}

	a.Add(1)

	if a.Cardinality() != 1 {
		t.Error("set should have a size of 1")
	}

	a.Remove(1)

	if a.Cardinality() != 0 {
		t.Error("set should be an empty set")
	}

	a.Add(9)

	if a.Cardinality() != 1 {
		t.Error("set should have a size of 1")
	}

	a.Clear()

	if a.Cardinality() != 0 {
		t.Error("set should have a size of 1")
	}
}

func Test_SetIsSubset(t *testing.T) {
	a := makeSet([]int{1, 2, 3, 5, 7})

	b := NewSet()
	b.Add(3)
	b.Add(5)
	b.Add(7)

	if !b.IsSubset(a) {
		t.Error("set b should be a subset of set a")
	}

	b.Add(72)

	if b.IsSubset(a) {
		t.Error("set b should not be a subset of set a because it contains 72 which is not in the set of a")
	}
}

func Test_SetIsProperSubset(t *testing.T) {
	a := makeSet([]int{1, 2, 3, 5, 7})
	b := makeSet([]int{7, 5, 3, 2, 1})

	if !a.IsSubset(b) {
		t.Error("set a should be a subset of set b")
	}
	if a.IsProperSubset(b) {
		t.Error("set a should not be a proper subset of set b (they're equal)")
	}

	b.Add(72)

	if !a.IsSubset(b) {
		t.Error("set a should be a subset of set b")
	}
	if !a.IsProperSubset(b) {
		t.Error("set a should be a proper subset of set b")
	}
}

func Test_UnsafeSetIsSubset(t *testing.T) {
	a := makeUnsafeSet([]int{1, 2, 3, 5, 7})

	b := NewUnsafeSet()
	b.Add(3)
	b.Add(5)
	b.Add(7)

	if !b.IsSubset(a) {
		t.Error("set b should be a subset of set a")
	}

	b.Add(72)

	if b.IsSubset(a) {
		t.Error("set b should not be a subset of set a because it contains 72 which is not in the set of a")
	}
}

func Test_UnsafeSetIsProperSubset(t *testing.T) {
	a := makeUnsafeSet([]int{1, 2, 3, 5, 7})
	b := NewUnsafeSet()
	b.Add(7)
	b.Add(1)
	b.Add(5)
	b.Add(3)
	b.Add(2)

	if !a.IsSubset(b) {
		t.Error("set a should be a subset of set b")
	}
	if a.IsProperSubset(b) {
		t.Error("set a should not be a proper subset of set b (they're equal)")
	}

	b.Add(72)

	if !a.IsSubset(b) {
		t.Error("set a should be a subset of set b")
	}
	if !a.IsProperSubset(b) {
		t.Error("set a should be a proper subset of set b because set b has 72")
	}
}

func Test_SetIsSuperset(t *testing.T) {
	a := NewSet()
	a.Add(9)
	a.Add(5)
	a.Add(2)
	a.Add(1)
	a.Add(11)

	b := NewSet()
	b.Add(5)
	b.Add(2)
	b.Add(11)

	if !a.IsSuperset(b) {
		t.Error("set a should be a superset of set b")
	}

	b.Add(42)

	if a.IsSuperset(b) {
		t.Error("set a should not be a superset of set b because set b has a 42")
	}
}

func Test_SetIsProperSuperset(t *testing.T) {
	a := NewSet()
	a.Add(5)
	a.Add(2)
	a.Add(11)

	b := NewSet()
	b.Add(2)
	b.Add(5)
	b.Add(11)

	if !a.IsSuperset(b) {
		t.Error("set a should be a superset of set b")
	}
	if a.IsProperSuperset(b) {
		t.Error("set a should not be a proper superset of set b (they're equal)")
	}

	a.Add(9)

	if !a.IsSuperset(b) {
		t.Error("set a should be a superset of set b")
	}
	if !a.IsProperSuperset(b) {
		t.Error("set a not be a proper superset of set b because set a has a 9")
	}

	b.Add(42)

	if a.IsSuperset(b) {
		t.Error("set a should not be a superset of set b because set b has a 42")
	}
	if a.IsProperSuperset(b) {
		t.Error("set a should not be a proper superset of set b because set b has a 42")
	}
}

func Test_UnsafeSetIsSuperset(t *testing.T) {
	a := NewUnsafeSet()
	a.Add(9)
	a.Add(5)
	a.Add(2)
	a.Add(1)
	a.Add(11)

	b := NewUnsafeSet()
	b.Add(5)
	b.Add(2)
	b.Add(11)

	if !a.IsSuperset(b) {
		t.Error("set a should be a superset of set b")
	}

	b.Add(42)

	if a.IsSuperset(b) {
		t.Error("set a should not be a superset of set b because set a has a 42")
	}
}

func Test_UnsafeSetIsProperSuperset(t *testing.T) {
	a := NewUnsafeSet()
	a.Add(5)
	a.Add(2)
	a.Add(11)

	b := NewUnsafeSet()
	b.Add(2)
	b.Add(5)
	b.Add(11)

	if !a.IsSuperset(b) {
		t.Error("set a should be a superset of set b")
	}
	if a.IsProperSuperset(b) {
		t.Error("set a should not be a proper superset of set b (they're equal)")
	}

	a.Add(9)

	if !a.IsSuperset(b) {
		t.Error("set a should be a superset of set b")
	}
	if !a.IsProperSuperset(b) {
		t.Error("set a not be a proper superset of set b because set a has a 9")
	}

	b.Add(42)

	if a.IsSuperset(b) {
		t.Error("set a should not be a superset of set b because set b has a 42")
	}
	if a.IsProperSuperset(b) {
		t.Error("set a should not be a proper superset of set b because set b has a 42")
	}
}

func Test_SetUnion(t *testing.T) {
	a := NewSet()

	b := NewSet()
	b.Add(1)
	b.Add(2)
	b.Add(3)
	b.Add(4)
	b.Add(5)

	c := a.Union(b)

	if c.Cardinality() != 5 {
		t.Error("set c is unioned with an empty set and therefore should have 5 elements in it")
	}

	d := NewSet()
	d.Add(10)
	d.Add(14)
	d.Add(0)

	e := c.Union(d)
	if e.Cardinality() != 8 {
		t.Error("set e should should have 8 elements in it after being unioned with set c to d")
	}

	f := NewSet()
	f.Add(14)
	f.Add(3)

	g := f.Union(e)
	if g.Cardinality() != 8 {
		t.Error("set g should still have 8 elements in it after being unioned with set f that has duplicates")
	}
}

func Test_UnsafeSetUnion(t *testing.T) {
	a := NewUnsafeSet()

	b := NewUnsafeSet()
	b.Add(1)
	b.Add(2)
	b.Add(3)
	b.Add(4)
	b.Add(5)

	c := a.Union(b)

	if c.Cardinality() != 5 {
		t.Error("set c is unioned with an empty set and therefore should have 5 elements in it")
	}

	d := NewUnsafeSet()
	d.Add(10)
	d.Add(14)
	d.Add(0)

	e := c.Union(d)
	if e.Cardinality() != 8 {
		t.Error("set e should should have 8 elements in it after being unioned with set c to d")
	}

	f := NewUnsafeSet()
	f.Add(14)
	f.Add(3)

	g := f.Union(e)
	if g.Cardinality() != 8 {
		t.Error("set g should still have 8 elements in it after being unioned with set f that has duplicates")
	}
}

func Test_SetIntersect(t *testing.T) {
	a := NewSet()
	a.Add(1)
	a.Add(3)
	a.Add(5)

	b := NewSet()
	a.Add(2)
	a.Add(4)
	a.Add(6)

	c := a.Intersect(b)

	if c.Cardinality() != 0 {
		t.Error("set c should be the empty set because there is no common items to intersect")
	}

	a.Add(10)
	b.Add(10)

	d := a.Intersect(b)

	if !(d.Cardinality() == 1 && d.Contains(10)) {
		t.Error("set d should have a size of 1 and contain the item 10")
	}
}

func Test_UnsafeSetIntersect(t *testing.T) {
	a := NewUnsafeSet()
	a.Add(1)
	a.Add(3)
	a.Add(5)

	b := NewUnsafeSet()
	a.Add(2)
	a.Add(4)
	a.Add(6)

	c := a.Intersect(b)

	if c.Cardinality() != 0 {
		t.Error("set c should be the empty set because there is no common items to intersect")
	}

	a.Add(10)
	b.Add(10)

	d := a.Intersect(b)

	if !(d.Cardinality() == 1 && d.Contains(10)) {
		t.Error("set d should have a size of 1 and contain the item 10")
	}
}

func Test_SetDifference(t *testing.T) {
	a := NewSet()
	a.Add(1)
	a.Add(2)
	a.Add(3)

	b := NewSet()
	b.Add(1)
	b.Add(3)
	b.Add(4)
	b.Add(5)
	b.Add(6)
	b.Add(99)

	c := a.Difference(b)

	if !(c.Cardinality() == 1 && c.Contains(2)) {
		t.Error("the difference of set a to b is the set of 1 item: 2")
	}
}

func Test_UnsafeSetDifference(t *testing.T) {
	a := NewUnsafeSet()
	a.Add(1)
	a.Add(2)
	a.Add(3)

	b := NewUnsafeSet()
	b.Add(1)
	b.Add(3)
	b.Add(4)
	b.Add(5)
	b.Add(6)
	b.Add(99)

	c := a.Difference(b)

	if !(c.Cardinality() == 1 && c.Contains(2)) {
		t.Error("the difference of set a to b is the set of 1 item: 2")
	}
}

func Test_SetSymmetricDifference(t *testing.T) {
	a := NewSet()
	a.Add(1)
	a.Add(2)
	a.Add(3)
	a.Add(45)

	b := NewSet()
	b.Add(1)
	b.Add(3)
	b.Add(4)
	b.Add(5)
	b.Add(6)
	b.Add(99)

	c := a.SymmetricDifference(b)

	if !(c.Cardinality() == 6 && c.Contains(2) && c.Contains(45) && c.Contains(4) && c.Contains(5) && c.Contains(6) && c.Contains(99)) {
		t.Error("the symmetric difference of set a to b is the set of 6 items: 2, 45, 4, 5, 6, 99")
	}
}

func Test_UnsafeSetSymmetricDifference(t *testing.T) {
	a := NewUnsafeSet()
	a.Add(1)
	a.Add(2)
	a.Add(3)
	a.Add(45)

	b := NewUnsafeSet()
	b.Add(1)
	b.Add(3)
	b.Add(4)
	b.Add(5)
	b.Add(6)
	b.Add(99)

	c := a.SymmetricDifference(b)

	if !(c.Cardinality() == 6 && c.Contains(2) && c.Contains(45) && c.Contains(4) && c.Contains(5) && c.Contains(6) && c.Contains(99)) {
		t.Error("the symmetric difference of set a to b is the set of 6 items: 2, 45, 4, 5, 6, 99")
	}
}

func Test_SetEqual(t *testing.T) {
	a := NewSet()
	b := NewSet()

	if !a.Equal(b) {
		t.Error("Both a and b are empty sets, and should be equal")
	}

	a.Add(10)

	if a.Equal(b) {
		t.Error("a should not be equal to b because b is empty and a has item 1 in it")
	}

	b.Add(10)

	if !a.Equal(b) {
		t.Error("a is now equal again to b because both have the item 10 in them")
	}

	b.Add(8)
	b.Add(3)
	b.Add(47)

	if a.Equal(b) {
		t.Error("b has 3 more elements in it so therefore should not be equal to a")
	}

	a.Add(8)
	a.Add(3)
	a.Add(47)

	if !a.Equal(b) {
		t.Error("a and b should be equal with the same number of elements")
	}
}

func Test_SetEqual_Subset(t *testing.T) {
	a := NewSet()
	b := NewSet()

	if !a.Equal(b) {
		t.Error("Both a and b are empty sets, and should be equal")
	}

	a.Add(NewUnsafeSet(10))

	if a.Equal(b) {
		t.Error("a should not be equal to b because b is empty and a has item 1 in it")
	}

	b.Add(NewSet(10))

	if !a.Equal(b) {
		t.Error("a is now equal again to b because both have the item 10 in them")
	}

	b.Add(8)
	b.Add(3)
	b.Add(47)

	if a.Equal(b) {
		t.Error("b has 3 more elements in it so therefore should not be equal to a")
	}

	a.Add(3)
	a.Add(8)
	a.Add(47)

	if !a.Equal(b) {
		t.Error("a and b should be equal with the same number of elements")
	}
}

func Test_UnsafeSetEqual(t *testing.T) {
	a := NewUnsafeSet()
	b := NewUnsafeSet()

	if !a.Equal(b) {
		t.Error("Both a and b are empty sets, and should be equal")
	}

	a.Add(10)

	if a.Equal(b) {
		t.Error("a should not be equal to b because b is empty and a has item 1 in it")
	}

	b.Add(10)

	if !a.Equal(b) {
		t.Error("a is now equal again to b because both have the item 10 in them")
	}

	b.Add(8)
	b.Add(3)
	b.Add(47)

	if a.Equal(b) {
		t.Error("b has 3 more elements in it so therefore should not be equal to a")
	}

	a.Add(8)
	a.Add(3)
	a.Add(47)

	if !a.Equal(b) {
		t.Error("a and b should be equal with the same number of elements")
	}
}

func Test_SetHash(t *testing.T) {
	a := NewSet()
	b := NewSet()

	a.Add("test")
	a.Remove("test")

	if a.Hash() != b.Hash() {
		t.Error("Both a and b are empty sets, and should have the same hashes")
	}

	a.Add(10)

	if a.Hash() == b.Hash() {
		t.Error("a should not be equal to b because b is empty and a has item 1 in it")
	}

	b.Add(10)

	if a.Hash() != b.Hash() {
		t.Error("a is now equal again to b because both have the item 10 in them")
	}

	b.Add(8)
	b.Add(3)
	b.Add(47)

	if a.Hash() == b.Hash() {
		t.Error("b has 3 more elements in it so therefore should not be equal to a")
	}

	a.Add(3, 8, 47)

	if a.Hash() != b.Hash() {
		t.Error("a and b should be equal with the same number of elements")
	}
}

func Test_UnsafeSetHash(t *testing.T) {
	a := NewUnsafeSet()
	b := NewUnsafeSet()

	a.Add("test")
	a.Remove("test")

	if a.Hash() != b.Hash() {
		t.Error("Both a and b are empty sets, and should have the same hashes")
	}

	a.Add(10)

	if a.Hash() == b.Hash() {
		t.Error("a should not be equal to b because b is empty and a has item 1 in it")
	}

	b.Add(10)

	if a.Hash() != b.Hash() {
		t.Error("a is now equal again to b because both have the item 10 in them")
	}

	b.Add(8)
	b.Add(3)
	b.Add(47)

	if a.Hash() == b.Hash() {
		t.Error("b has 3 more elements in it so therefore should not be equal to a")
	}

	a.Add(3, 8, 47)

	if a.Hash() != b.Hash() {
		t.Error("a and b should be equal with the same number of elements")
	}
}

func Test_SetUpdateHash(t *testing.T) {
	a := NewSet()
	b := NewSet()

	a.Add("test")
	a.Remove("test")

	if a.Hash() != b.Hash() {
		t.Error("Both a and b are empty sets, and should have the same hashes")
	}

	subSetA := NewSet("foo")
	subSetB := NewSet("foo")

	a.Add(subSetA)

	if a.Hash() == b.Hash() {
		t.Error("a should not be equal to b because b is empty and a has item Set{foo} in it")
	}

	b.Add(subSetB)

	if a.Hash() != b.Hash() {
		t.Error("a is now equal again to b because both have the item Set{foo} in them")
	}

	subSetA.Add("bar")

	if a.Hash() != b.Hash() {
		t.Error("both sets should be equal since the change in the subset should not be recognized implicitly")
	}

	updatedA := a.UpdateHash()

	if a.Hash() == b.Hash() || updatedA != 1 {
		t.Error("a has been updated now and the change in Set{foo, bar} should be recognized")
	}

	subSetB.Add("bar")
	updatedB := b.UpdateHash()

	if a.Hash() != b.Hash() || updatedB != 1 {
		t.Error("a and b should be equal with the same number of elements")
	}
}

func Test_UnsafeSetUpdateHash(t *testing.T) {
	a := NewUnsafeSet()
	b := NewUnsafeSet()

	a.Add("test")
	a.Remove("test")

	if a.Hash() != b.Hash() {
		t.Error("Both a and b are empty sets, and should have the same hashes")
	}

	subSetA := NewSet("foo")
	subSetB := NewSet("foo")

	a.Add(subSetA)

	if a.Hash() == b.Hash() {
		t.Error("a should not be equal to b because b is empty and a has item Set{foo} in it")
	}

	b.Add(subSetB)

	if a.Hash() != b.Hash() {
		t.Error("a is now equal again to b because both have the item Set{foo} in them")
	}

	subSetA.Add("bar")

	if a.Hash() != b.Hash() {
		t.Error("both sets should be equal since the change in the subset should not be recognized implicitly")
	}

	updatedA := a.UpdateHash()

	if a.Hash() == b.Hash() || updatedA != 1 {
		t.Error("a has been updated now and the change in Set{foo, bar} should be recognized")
	}

	subSetB.Add("bar")
	updatedB := b.UpdateHash()

	if a.Hash() != b.Hash() || updatedB != 1 {
		t.Error("a and b should be equal with the same number of elements")
	}
}

func Test_SetClone(t *testing.T) {
	a := NewSet()
	a.Add(1)
	a.Add(2)

	b := a.Clone()

	if !a.Equal(b) {
		t.Error("Clones should be equal")
	}

	a.Add(3)
	if a.Equal(b) {
		t.Error("a contains one more element, they should not be equal")
	}

	c := a.Clone()
	c.Remove(1)

	if a.Equal(c) {
		t.Error("C contains one element less, they should not be equal")
	}
}

func Test_UnsafeSetClone(t *testing.T) {
	a := NewUnsafeSet()
	a.Add(1)
	a.Add(2)

	b := a.Clone()

	if !a.Equal(b) {
		t.Error("Clones should be equal")
	}

	a.Add(3)
	if a.Equal(b) {
		t.Error("a contains one more element, they should not be equal")
	}

	c := a.Clone()
	c.Remove(1)

	if a.Equal(c) {
		t.Error("C contains one element less, they should not be equal")
	}
}

func Test_Each(t *testing.T) {
	a := NewSet()

	a.Add("Z")
	a.Add("Y")
	a.Add("X")
	a.Add("W")

	b := NewSet()
	a.Each(func(elem interface{}) bool {
		b.Add(elem)
		return false
	})

	if !a.Equal(b) {
		t.Error("The sets are not equal after iterating (Each) through the first set")
	}

	var count int
	a.Each(func(elem interface{}) bool {
		if count == 2 {
			return true
		}
		count++
		return false
	})
	if count != 2 {
		t.Error("Iteration should stop on the way")
	}
}

func Test_Iter(t *testing.T) {
	a := NewSet()

	a.Add("Z")
	a.Add("Y")
	a.Add("X")
	a.Add("W")

	b := NewSet()
	for val := range a.Iter() {
		b.Add(val)
	}

	if !a.Equal(b) {
		t.Error("The sets are not equal after iterating (Iter) through the first set")
	}
}

func Test_UnsafeIter(t *testing.T) {
	a := NewUnsafeSet()

	a.Add("Z")
	a.Add("Y")
	a.Add("X")
	a.Add("W")

	b := NewUnsafeSet()
	for val := range a.Iter() {
		b.Add(val)
	}

	if !a.Equal(b) {
		t.Error("The sets are not equal after iterating (Iter) through the first set")
	}
}

func Test_Iterator(t *testing.T) {
	a := NewSet()

	a.Add("Z")
	a.Add("Y")
	a.Add("X")
	a.Add("W")

	b := NewSet()
	for val := range a.Iterator().C {
		b.Add(val)
	}

	if !a.Equal(b) {
		t.Error("The sets are not equal after iterating (Iterator) through the first set")
	}
}

func Test_UnsafeIterator(t *testing.T) {
	a := NewUnsafeSet()

	a.Add("Z")
	a.Add("Y")
	a.Add("X")
	a.Add("W")

	b := NewUnsafeSet()
	for val := range a.Iterator().C {
		b.Add(val)
	}

	if !a.Equal(b) {
		t.Error("The sets are not equal after iterating (Iterator) through the first set")
	}
}

func Test_IteratorStop(t *testing.T) {
	a := NewSet()

	a.Add("Z")
	a.Add("Y")
	a.Add("X")
	a.Add("W")

	it := a.Iterator()
	it.Stop()
	for range it.C {
		t.Error("The iterating (Iterator) did not stop after Stop() has been called")
	}
}

func Test_PopSafe(t *testing.T) {
	a := NewSet()

	a.Add("a")
	a.Add("b")
	a.Add("c")
	a.Add("d")

	captureSet := NewSet()
	captureSet.Add(a.Pop())
	captureSet.Add(a.Pop())
	captureSet.Add(a.Pop())
	captureSet.Add(a.Pop())
	finalNil := a.Pop()

	if captureSet.Cardinality() != 4 {
		t.Error("unexpected captureSet cardinality; should be 4")
	}

	if a.Cardinality() != 0 {
		t.Error("unepxected a cardinality; should be zero")
	}

	if !captureSet.Contains("c", "a", "d", "b") {
		t.Error("unexpected result set; should be a,b,c,d (any order is fine")
	}

	if finalNil != nil {
		t.Error("when original set is empty, further pops should result in nil")
	}
}

func Test_PopUnsafe(t *testing.T) {
	a := NewUnsafeSet()

	a.Add("a")
	a.Add("b")
	a.Add("c")
	a.Add("d")

	captureSet := NewUnsafeSet()
	captureSet.Add(a.Pop())
	captureSet.Add(a.Pop())
	captureSet.Add(a.Pop())
	captureSet.Add(a.Pop())
	finalNil := a.Pop()

	if captureSet.Cardinality() != 4 {
		t.Error("unexpected captureSet cardinality; should be 4")
	}

	if a.Cardinality() != 0 {
		t.Error("unepxected a cardinality; should be zero")
	}

	if !captureSet.Contains("c", "a", "d", "b") {
		t.Error("unexpected result set; should be a,b,c,d (any order is fine")
	}

	if finalNil != nil {
		t.Error("when original set is empty, further pops should result in nil")
	}
}

func Test_PowerSet(t *testing.T) {
	a := NewSet()

	a.Add(1)
	a.Add("delta")
	a.Add("chi")
	a.Add(4)

	b := a.PowerSet()
	if b.Cardinality() != 16 {
		t.Error("unexpected PowerSet cardinality")
	}
}

func Test_PowerSetThreadSafe(t *testing.T) {
	set := NewSet().PowerSet()
	_, setIsThreadSafe := set.(*threadSafeSet)
	if !setIsThreadSafe {
		t.Error("result of PowerSet should be thread safe")
	}

	subset := set.Pop()
	_, subsetIsThreadSafe := subset.(*threadSafeSet)
	if !subsetIsThreadSafe {
		t.Error("subsets in PowerSet result should be thread safe")
	}
}

func Test_EmptySetProperties(t *testing.T) {
	empty := NewSet()

	a := NewSet()
	a.Add(1)
	a.Add("foo")
	a.Add("bar")

	b := NewSet()
	b.Add("one")
	b.Add("two")
	b.Add(3)
	b.Add(4)

	if !empty.IsSubset(a) || !empty.IsSubset(b) {
		t.Error("The empty set is supposed to be a subset of all sets")
	}

	if !a.IsSuperset(empty) || !b.IsSuperset(empty) {
		t.Error("All sets are supposed to be a superset of the empty set")
	}

	if !empty.IsSubset(empty) || !empty.IsSuperset(empty) {
		t.Error("The empty set is supposed to be a subset and a superset of itself")
	}

	c := a.Union(empty)
	if !c.Equal(a) {
		t.Error("The union of any set with the empty set is supposed to be equal to itself")
	}

	c = a.Intersect(empty)
	if !c.Equal(empty) {
		t.Error("The intesection of any set with the empty set is supposed to be the empty set")
	}

	c = a.CartesianProduct(empty)
	if c.Cardinality() != 0 {
		t.Error("Cartesian product of any set and the empty set must be the empty set")
	}

	if empty.Cardinality() != 0 {
		t.Error("Cardinality of the empty set is supposed to be zero")
	}

	c = empty.PowerSet()
	if c.Cardinality() != 1 {
		t.Error("Cardinality of the power set of the empty set is supposed to be one { {} }")
	}
}

func Test_CartesianProduct(t *testing.T) {
	a := NewSet()
	b := NewSet()
	empty := NewSet()

	a.Add(1)
	a.Add(2)
	a.Add(3)

	b.Add("one")
	b.Add("two")
	b.Add("three")
	b.Add("alpha")
	b.Add("gamma")

	c := a.CartesianProduct(b)
	d := b.CartesianProduct(a)

	if c.Cardinality() != d.Cardinality() {
		t.Error("Cardinality of AxB must be equal to BxA")
	}

	if c.Cardinality() != (a.Cardinality() * b.Cardinality()) {
		t.Error("Unexpected cardinality for cartesian product set")
	}

	c = a.CartesianProduct(empty)
	d = empty.CartesianProduct(b)

	if c.Cardinality() != 0 || d.Cardinality() != 0 {
		t.Error("Cartesian product of any set and the empty set Ax0 || 0xA must be the empty set")
	}
}

func Test_ToSliceUnthreadsafe(t *testing.T) {
	s := makeUnsafeSet([]int{1, 2, 3})
	setAsSlice := s.ToSlice()
	if len(setAsSlice) != s.Cardinality() {
		t.Errorf("Set length is incorrect: %v", len(setAsSlice))
	}

	for _, i := range setAsSlice {
		if !s.Contains(i) {
			t.Errorf("Set is missing element: %v", i)
		}
	}
}