reader_test.go

package gopherng_test

import (
	"bytes"
	_ "embed"
	"fmt"
	"io"
	"testing"

	"github.com/ethanent/gopherng/v2"
)

//go:embed testdata/seed0_out.bin
var seed0out []byte

//go:embed testdata/seed1_out.bin
var seed1out []byte

func ExampleReader() {
	// Create PseudorandomReader with a seed. Use a high entropy seed in most
	// real use cases.
	r := gopherng.NewReader([]byte{1, 2, 3, 4, 5})

	p := make([]byte, 256)
	_, err := r.Read(p)
	if err != nil {
		/* ... */
	}

	fmt.Println(p)
	// => [43 98 21 80 122 33 48 91 135 248 242 ... ]
}

func TestPseudorandomReader(t *testing.T) {
	tests := []struct {
		seed   []byte
		expect []byte
	}{
		{
			seed:   []byte("seed0"),
			expect: seed0out,
		},
		{
			seed:   []byte("seed1"),
			expect: seed1out,
		},
	}
	for _, c := range tests {
		reader := gopherng.NewReader(c.seed)
		o := make([]byte, 1024*2)
		if _, err := io.ReadFull(reader, o); err != nil {
			t.Fatal(err)
		}
		if !bytes.Equal(o, c.expect[:len(o)]) {
			t.Errorf("expect and read data were not equal")
		}
	}
}