queue_test.go

package queue

import (
	"reflect"
	"testing"
)

func TestQueueBasic(t *testing.T) {
	q := New[int](2)

	if q.Len() != 0 {
		t.Fatalf("len = %d", q.Len())
	}
	if _, ok := q.Pop(); ok {
		t.Fatal("pop on empty should be !ok")
	}

	for i := 1; i <= 10; i++ {
		q.Push(i)
	}
	if q.Len() != 10 {
		t.Fatalf("len = %d", q.Len())
	}
	if v, _ := q.Peek(); v != 1 {
		t.Fatalf("peek = %d", v)
	}

	want := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
	if got := q.Snapshot(); !reflect.DeepEqual(got, want) {
		t.Fatalf("snapshot = %v", got)
	}

	for _, w := range want {
		got, ok := q.Pop()
		if !ok || got != w {
			t.Fatalf("pop = %d %v, want %d", got, ok, w)
		}
	}
	if q.Len() != 0 {
		t.Fatalf("expected empty, got %d", q.Len())
	}
}

func TestQueueWrapAround(t *testing.T) {
	q := New[int](4)
	for i := 0; i < 3; i++ {
		q.Push(i)
	}
	q.Pop()
	q.Pop()
	for i := 3; i < 7; i++ {
		q.Push(i)
	}
	want := []int{2, 3, 4, 5, 6}
	if got := q.Snapshot(); !reflect.DeepEqual(got, want) {
		t.Fatalf("snapshot = %v, want %v", got, want)
	}
}

func TestQueueGrowsLinear(t *testing.T) {
	q := New[int](4)
	for i := 0; i < 100; i++ {
		q.Push(i)
	}
	for i := 0; i < 100; i++ {
		got, ok := q.Pop()
		if !ok || got != i {
			t.Fatalf("at %d got %d %v", i, got, ok)
		}
	}
}