murmur3_32_test.gno

  1package murmur3_test
  2
  3import (
  4	"testing"
  5
  6	"gno.land/p/jeronimoalbi/murmur3"
  7)
  8
  9func TestHash32Sum32(t *testing.T) {
 10	// Test cases -> https://en.wikipedia.org/wiki/MurmurHash#Algorithm
 11	tests := []struct {
 12		name string
 13		data string
 14		seed uint32
 15		want uint32
 16	}{
 17		{"empty with seed 0", "", 0, 0},
 18		{"empty with seed 1", "", 1, 0x514e28b7},
 19		{"empty with seed max", "", 0xffffffff, 0x81f16f39},
 20		{"test", "test", 0, 0xba6bd213},
 21		{"test with seed", "test", 0x9747b28c, 0x704b81dc},
 22		{"hello", "Hello, world!", 0, 0xc0363e43},
 23		{"hello with seed", "Hello, world!", 42, 0x2c8c8533},
 24		{"hello with seed 0x9747b28c", "Hello, world!", 0x9747b28c, 0x24884cba},
 25		{"pangram", "The quick brown fox jumps over the lazy dog", 0, 0x2e4ff723},
 26		{"pangram with seed", "The quick brown fox jumps over the lazy dog", 0x9747b28c, 0x2fa826cd},
 27	}
 28
 29	for _, tt := range tests {
 30		t.Run(tt.name, func(t *testing.T) {
 31			got := murmur3.Sum32WithSeed([]byte(tt.data), tt.seed)
 32			if got != tt.want {
 33				t.Errorf("Sum32WithSeed(%q, %d) = 0x%08x, want 0x%08x", tt.data, tt.seed, got, tt.want)
 34			}
 35		})
 36	}
 37}
 38
 39func TestHash32InterfaceSizes(t *testing.T) {
 40	h := murmur3.New32()
 41	if h.Size() != 4 {
 42		t.Errorf("Size() = %d, want 4", h.Size())
 43	}
 44	if h.BlockSize() != 4 {
 45		t.Errorf("BlockSize() = %d, want 4", h.BlockSize())
 46	}
 47}
 48
 49func TestHash32IncrementalWrite(t *testing.T) {
 50	want := uint32(3224780355)
 51	data := []byte("Hello, world!")
 52
 53	// Hash one byte at a time
 54	h := murmur3.New32()
 55	for _, b := range data {
 56		h.Write([]byte{b})
 57	}
 58
 59	if got := h.Sum32(); got != want {
 60		t.Errorf("incremental Write got 0x%08x, want 0x%08x", got, want)
 61	}
 62
 63	// Hash in two parts
 64	h.Reset()
 65	h.Write(data[:5])
 66	h.Write(data[5:])
 67	if got := h.Sum32(); got != want {
 68		t.Errorf("two-part Write got 0x%08x, want 0x%08x", got, want)
 69	}
 70}
 71
 72func TestHash32Sum(t *testing.T) {
 73	h := murmur3.New32()
 74	h.Write([]byte("Hello, world!"))
 75	b := h.Sum(nil)
 76	if len(b) != 4 {
 77		t.Fatalf("Sum(nil) returned %d bytes, want 4", len(b))
 78	}
 79
 80	got := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
 81	want := uint32(3224780355)
 82	if got != want {
 83		t.Errorf("Sum got 0x%08x, want 0x%08x", got, want)
 84	}
 85}
 86
 87func TestHash32SumDoesNotChangeState(t *testing.T) {
 88	h := murmur3.New32()
 89	h.Write([]byte("Hello"))
 90	s1 := h.Sum32()
 91	s2 := h.Sum32()
 92	if s1 != s2 {
 93		t.Errorf("Sum32 changed state: first 0x%08x, second 0x%08x", s1, s2)
 94	}
 95}
 96
 97func TestHash32Reset(t *testing.T) {
 98	h := murmur3.New32()
 99	h.Write([]byte("some data"))
100	h.Reset()
101	h.Write([]byte("Hello, world!"))
102	got := h.Sum32()
103	want := uint32(3224780355)
104	if got != want {
105		t.Errorf("after Reset got 0x%08x, want 0x%08x", got, want)
106	}
107}