gds/queue_test.go at main · renaldid/gds · GitHub

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package gds

import (
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestQueue_Empty(t *testing.T) {
	q := NewQueue[int]()
	assert.Equal(t, 0, q.Len())
	assert.True(t, q.IsEmpty())
}

func TestQueue_Enqueue_And_Dequeue(t *testing.T) {
	q := NewQueue[int]()
	q.Enqueue(1, 2, 3)
	v, ok := q.Dequeue()
	assert.True(t, ok)
	assert.Equal(t, 1, v)
	assert.Equal(t, 2, q.Len())
}

func TestQueue_Dequeue_Empty(t *testing.T) {
	q := NewQueue[int]()
	v, ok := q.Dequeue()
	assert.False(t, ok)
	assert.Zero(t, v)
}

func TestQueue_Peek(t *testing.T) {
	q := NewQueue[string]()
	q.Enqueue("a", "b")
	v, ok := q.Peek()
	assert.True(t, ok)
	assert.Equal(t, "a", v)
	assert.Equal(t, 2, q.Len()) // not removed
}

func TestQueue_Peek_Empty(t *testing.T) {
	q := NewQueue[string]()
	v, ok := q.Peek()
	assert.False(t, ok)
	assert.Empty(t, v)
}

func TestQueue_FIFO_Order(t *testing.T) {
	q := NewQueue[int]()
	q.Enqueue(1, 2, 3)
	var got []int
	for !q.IsEmpty() {
		v, _ := q.Dequeue()
		got = append(got, v)
	}
	assert.Equal(t, []int{1, 2, 3}, got)
}

func TestQueue_Compaction(t *testing.T) {
	// dequeue enough to trigger the compaction path (head >= len/2)
	q := NewQueue[int]()
	for i := range 10 {
		q.Enqueue(i)
	}
	for range 6 {
		q.Dequeue()
	}
	// after compaction head resets to 0; remaining elements still correct
	v, ok := q.Dequeue()
	assert.True(t, ok)
	assert.Equal(t, 6, v)
	assert.Equal(t, 3, q.Len())
}

func TestQueue_Clear(t *testing.T) {
	q := NewQueue[int]()
	q.Enqueue(1, 2, 3)
	q.Clear()
	assert.True(t, q.IsEmpty())
	assert.Equal(t, 0, q.Len())
}