Began implementing the stack and the stack stack

pkg/stack/stack_test.go

@@ -0,0 +1,83 @@
+package stack
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewStack(t *testing.T) {
+	require.Equal(t, NewStack(), &Stack{
+		size:   32,
+		height: 0,
+		data:   make([]int, 32),
+		next:   nil,
+	})
+}
+
+func TestClear(t *testing.T) {
+	s := NewStack()
+	s.Clear()
+	require.Equal(t, s.height, 0)
+}
+
+func TestDupicate(t *testing.T) {
+	s := NewStack()
+	s2 := NewStack()
+	s.Duplicate()
+	require.Equal(t, s.height, s2.height)
+	s.Push(12)
+	s.Duplicate()
+	s2.Push(12)
+	s2.Push(12)
+	require.Equal(t, s.height, s2.height)
+	require.Equal(t, s.data, s2.data)
+}
+
+func TestPop(t *testing.T) {
+	s := NewStack()
+	v := s.Pop()
+	require.Equal(t, v, 0)
+	s.Push(12)
+	s.Push(14)
+	v = s.Pop()
+	require.Equal(t, v, 14)
+	v = s.Pop()
+	require.Equal(t, v, 12)
+	v = s.Pop()
+	require.Equal(t, v, 0)
+}
+
+func TestPush(t *testing.T) {
+	s := NewStack()
+	for i := 0; i < 32; i++ {
+		s.Push(i)
+	}
+	require.Equal(t, s.size, 32)
+	s.Push(-1)
+	require.Equal(t, s.size, 64)
+}
+
+func TestSwap(t *testing.T) {
+	s := NewStack()
+	s2 := NewStack()
+	s.Swap()
+	s2.Push(0)
+	s2.Push(0)
+	require.Equal(t, s, s2)
+	s.Clear()
+	s.Push(1)
+	s.Swap()
+	s2.Clear()
+	s2.Push(1)
+	s2.Push(0)
+	require.Equal(t, s, s2)
+	s.Clear()
+	s.Push(1)
+	s.Push(2)
+	s2.Clear()
+	s2.Push(2)
+	s2.Push(1)
+	s.Swap()
+	require.Equal(t, s, s2)
+}