tendermint/libs/os/os_test.go

package os

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"testing"
)

func TestCopyFile(t *testing.T) {
	tmpfile, err := ioutil.TempFile("", "example")
	if err != nil {
		t.Fatal(err)
	}
	defer os.Remove(tmpfile.Name())
	content := []byte("hello world")
	if _, err := tmpfile.Write(content); err != nil {
		t.Fatal(err)
	}

	copyfile := fmt.Sprintf("%s.copy", tmpfile.Name())
	if err := CopyFile(tmpfile.Name(), copyfile); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(copyfile); os.IsNotExist(err) {
		t.Fatal("copy should exist")
	}
	data, err := ioutil.ReadFile(copyfile)
	if err != nil {
		t.Fatal(err)
	}
	if !bytes.Equal(data, content) {
		t.Fatalf("copy file content differs: expected %v, got %v", content, data)
	}
	os.Remove(copyfile)
}