move implementation to internal/ directory (#828)

internal/zfs/zfscmd/zfscmd_platform_test.go

@@ -0,0 +1,125 @@
+package zfscmd
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/zrepl/zrepl/internal/util/circlog"
+)
+
+const testBin = "./zfscmd_platform_test.bash"
+
+func TestCmdStderrBehaviorOutput(t *testing.T) {
+
+	stdout, err := exec.Command(testBin, "0").Output()
+	require.NoError(t, err)
+	require.Equal(t, []byte("to stdout\n"), stdout)
+
+	stdout, err = exec.Command(testBin, "1").Output()
+	assert.Equal(t, []byte("to stdout\n"), stdout)
+	require.Error(t, err)
+	ee, ok := err.(*exec.ExitError)
+	require.True(t, ok)
+	require.Equal(t, ee.Stderr, []byte("to stderr\n"))
+}
+
+func TestCmdStderrBehaviorCombinedOutput(t *testing.T) {
+
+	stdio, err := exec.Command(testBin, "0").CombinedOutput()
+	require.NoError(t, err)
+	require.Equal(t, "to stderr\nto stdout\n", string(stdio))
+
+	stdio, err = exec.Command(testBin, "1").CombinedOutput()
+	require.Equal(t, "to stderr\nto stdout\n", string(stdio))
+	require.Error(t, err)
+	ee, ok := err.(*exec.ExitError)
+	require.True(t, ok)
+	require.Empty(t, ee.Stderr) // !!!! maybe not what one would expect
+}
+
+func TestCmdStderrBehaviorStdoutPipe(t *testing.T) {
+	cmd := exec.Command(testBin, "1")
+	stdoutPipe, err := cmd.StdoutPipe()
+	require.NoError(t, err)
+	err = cmd.Start()
+	require.NoError(t, err)
+	defer cmd.Wait()
+	var stdout bytes.Buffer
+	_, err = io.Copy(&stdout, stdoutPipe)
+	require.NoError(t, err)
+	require.Equal(t, "to stdout\n", stdout.String())
+
+	err = cmd.Wait()
+	require.Error(t, err)
+	ee, ok := err.(*exec.ExitError)
+	require.True(t, ok)
+	require.Empty(t, ee.Stderr) // !!!!! probably not what one would expect if we only redirect stdout
+}
+
+func TestCmdProcessState(t *testing.T) {
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	cmd := exec.CommandContext(ctx, "bash", "-c", "echo running; sleep 3600")
+	stdout, err := cmd.StdoutPipe()
+	require.NoError(t, err)
+	err = cmd.Start()
+	require.NoError(t, err)
+
+	r := bufio.NewReader(stdout)
+	line, err := r.ReadString('\n')
+	require.NoError(t, err)
+	require.Equal(t, "running\n", line)
+
+	// we know it's running and sleeping
+	cancel()
+	err = cmd.Wait()
+	t.Logf("wait err %T\n%s", err, err)
+	require.Error(t, err)
+	ee, ok := err.(*exec.ExitError)
+	require.True(t, ok)
+	require.NotNil(t, ee.ProcessState)
+	require.Contains(t, ee.Error(), "killed")
+}
+
+func TestSigpipe(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	cmd := CommandContext(ctx, "bash", "-c", "sleep 5; echo invalid input; exit 23")
+	r, w, err := os.Pipe()
+	require.NoError(t, err)
+	output := circlog.MustNewCircularLog(1 << 20)
+	cmd.SetStdio(Stdio{
+		Stdin:  r,
+		Stdout: output,
+		Stderr: output,
+	})
+	err = cmd.Start()
+	require.NoError(t, err)
+	err = r.Close()
+	require.NoError(t, err)
+
+	// the script doesn't read stdin, but this input is almost certainly smaller than the pipe buffer
+	const LargerThanPipeBuffer = 1 << 21
+	_, err = io.Copy(w, bytes.NewBuffer(bytes.Repeat([]byte("i"), LargerThanPipeBuffer)))
+	// => io.Copy is going to block because the pipe buffer is full and the
+	//    script is not reading from it
+	// => the script is going to exit after 5s
+	// => we should expect a broken pipe error from the copier's perspective
+	t.Logf("copy err = %T: %s", err, err)
+	require.NotNil(t, err)
+	require.True(t, strings.Contains(err.Error(), "broken pipe"))
+
+	err = cmd.Wait()
+	require.EqualError(t, err, "exit status 23")
+
+}