algorithms/ring_buffer_test.go at main · rubenmeza/algorithms · GitHub

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package algorithms

import "testing"

func TestRingBufferPushPop(t *testing.T) {
	r := NewRingBuffer[int](3)
	r.Push(1)
	r.Push(2)
	r.Push(3)

	val, ok := r.Pop()
	if !ok || val != 1 {
		t.Fatalf("expected 1, got %d", val)
	}
	val, ok = r.Pop()
	if !ok || val != 2 {
		t.Fatalf("expected 2, got %d", val)
	}
}

func TestRingBufferGrow(t *testing.T) {
	r := NewRingBuffer[int](2)
	r.Push(1)
	r.Push(2)
	r.Push(3)

	if r.Len() != 3 {
		t.Fatalf("expected len 3, got %d", r.Len())
	}
	val, ok := r.Pop()
	if !ok || val != 1 {
		t.Fatalf("expected 1, got %d", val)
	}
	val, ok = r.Pop()
	if !ok || val != 2 {
		t.Fatalf("expected 2, got %d", val)
	}
	val, ok = r.Pop()
	if !ok || val != 3 {
		t.Fatalf("expected 3, got %d", val)
	}
}

func TestRingBufferGrowAfterWrap(t *testing.T) {
	r := NewRingBuffer[int](3)
	r.Push(1)
	r.Push(2)
	r.Push(3)
	r.Pop()
	r.Pop()
	r.Push(4)
	r.Push(5)
	r.Push(6)

	for _, expected := range []int{3, 4, 5, 6} {
		val, ok := r.Pop()
		if !ok || val != expected {
			t.Fatalf("expected %d, got %d", expected, val)
		}
	}
}

func TestRingBufferPopEmpty(t *testing.T) {
	r := NewRingBuffer[int](2)
	_, ok := r.Pop()
	if ok {
		t.Fatal("expected false on empty pop")
	}
}

func TestRingBufferWrapAround(t *testing.T) {
	r := NewRingBuffer[string](3)
	r.Push("a")
	r.Push("b")
	r.Push("c")
	r.Pop()
	r.Pop()
	r.Push("d")
	r.Push("e")

	val, ok := r.Pop()
	if !ok || val != "c" {
		t.Fatalf("expected c, got %s", val)
	}
	val, ok = r.Pop()
	if !ok || val != "d" {
		t.Fatalf("expected d, got %s", val)
	}
	val, ok = r.Pop()
	if !ok || val != "e" {
		t.Fatalf("expected e, got %s", val)
	}
}

func TestRingBufferPeek(t *testing.T) {
	r := NewRingBuffer[int](2)
	r.Push(1)

	val, ok := r.Peek()
	if !ok || val != 1 {
		t.Fatalf("expected 1, got %d", val)
	}
	if r.Len() != 1 {
		t.Fatal("peek should not remove elements")
	}
}

func TestRingBufferIsEmpty(t *testing.T) {
	r := NewRingBuffer[int](2)
	if !r.IsEmpty() {
		t.Fatal("new buffer should be empty")
	}
	r.Push(1)
	if r.IsEmpty() {
		t.Fatal("buffer with items should not be empty")
	}
}