hashmap_test.go

package hashmap

import (
	"fmt"
	"testing"
)

func TestPutGet(t *testing.T) {
	m := New[string, int]()
	if _, ok := m.Get("missing"); ok {
		t.Fatal("expected !ok")
	}

	if _, existed := m.Put("a", 1); existed {
		t.Fatal("did not expect existed=true")
	}
	if _, existed := m.Put("b", 2); existed {
		t.Fatal("did not expect existed=true")
	}
	if old, existed := m.Put("a", 10); !existed || old != 1 {
		t.Fatalf("Put existing key: old=%d existed=%v", old, existed)
	}

	if v, ok := m.Get("a"); !ok || v != 10 {
		t.Errorf("Get a = %d %v", v, ok)
	}
	if v, ok := m.Get("b"); !ok || v != 2 {
		t.Errorf("Get b = %d %v", v, ok)
	}
	if m.Len() != 2 {
		t.Errorf("Len = %d", m.Len())
	}
}

func TestDelete(t *testing.T) {
	m := New[string, int]()
	m.Put("a", 1)
	m.Put("b", 2)
	if old, ok := m.Delete("a"); !ok || old != 1 {
		t.Fatalf("delete a: %d %v", old, ok)
	}
	if _, ok := m.Get("a"); ok {
		t.Error("expected a to be gone")
	}
	if _, ok := m.Delete("nope"); ok {
		t.Error("expected delete missing -> !ok")
	}
	if m.Len() != 1 {
		t.Errorf("Len = %d", m.Len())
	}
}

func TestResize(t *testing.T) {
	m := New[int, int]()
	const n = 1000
	for i := 0; i < n; i++ {
		m.Put(i, i*i)
	}
	if m.Len() != n {
		t.Fatalf("Len = %d", m.Len())
	}
	for i := 0; i < n; i++ {
		v, ok := m.Get(i)
		if !ok || v != i*i {
			t.Fatalf("Get(%d) = %d %v", i, v, ok)
		}
	}
}

func TestRange(t *testing.T) {
	m := New[string, int]()
	for i := 0; i < 5; i++ {
		m.Put(fmt.Sprintf("k%d", i), i)
	}
	count := 0
	m.Range(func(_ string, _ int) bool {
		count++
		return true
	})
	if count != 5 {
		t.Errorf("Range visited %d, want 5", count)
	}
}