Drop support for Go 1.8

Drop support for Go 1.8. Since all supported versions of Go now have
type aliases, we can drop some duplicated code.

zaptest/writer.go

@@ -18,81 +18,27 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-// +build !go1.9
-
 package zaptest
 
-import (
-	"bytes"
-	"errors"
-	"io/ioutil"
-	"strings"
-)
-
-// A Syncer is a spy for the Sync portion of zapcore.WriteSyncer.
-type Syncer struct {
-	err    error
-	called bool
-}
-
-// SetError sets the error that the Sync method will return.
-func (s *Syncer) SetError(err error) {
-	s.err = err
-}
-
-// Sync records that it was called, then returns the user-supplied error (if
-// any).
-func (s *Syncer) Sync() error {
-	s.called = true
-	return s.err
-}
-
-// Called reports whether the Sync method was called.
-func (s *Syncer) Called() bool {
-	return s.called
-}
+import "go.uber.org/zap/internal/ztest"
 
-// A Discarder sends all writes to ioutil.Discard.
-type Discarder struct{ Syncer }
+type (
+	// A Syncer is a spy for the Sync portion of zapcore.WriteSyncer.
+	Syncer = ztest.Syncer
 
-// Write implements io.Writer.
-func (d *Discarder) Write(b []byte) (int, error) {
-	return ioutil.Discard.Write(b)
-}
+	// A Discarder sends all writes to ioutil.Discard.
+	Discarder = ztest.Discarder
 
-// FailWriter is a WriteSyncer that always returns an error on writes.
-type FailWriter struct{ Syncer }
+	// FailWriter is a WriteSyncer that always returns an error on writes.
+	FailWriter = ztest.FailWriter
 
-// Write implements io.Writer.
-func (w FailWriter) Write(b []byte) (int, error) {
-	return len(b), errors.New("failed")
-}
+	// ShortWriter is a WriteSyncer whose write method never returns an error,
+	// but always reports that it wrote one byte less than the input slice's
+	// length (thus, a "short write").
+	ShortWriter = ztest.ShortWriter
 
-// ShortWriter is a WriteSyncer whose write method never fails, but
-// nevertheless fails to the last byte of the input.
-type ShortWriter struct{ Syncer }
-
-// Write implements io.Writer.
-func (w ShortWriter) Write(b []byte) (int, error) {
-	return len(b) - 1, nil
-}
-
-// Buffer is an implementation of zapcore.WriteSyncer that sends all writes to
-// a bytes.Buffer. It has convenience methods to split the accumulated buffer
-// on newlines.
-type Buffer struct {
-	bytes.Buffer
-	Syncer
-}
-
-// Lines returns the current buffer contents, split on newlines.
-func (b *Buffer) Lines() []string {
-	output := strings.Split(b.String(), "\n")
-	return output[:len(output)-1]
-}
-
-// Stripped returns the current buffer contents with the last trailing newline
-// stripped.
-func (b *Buffer) Stripped() string {
-	return strings.TrimRight(b.String(), "\n")
-}
+	// Buffer is an implementation of zapcore.WriteSyncer that sends all writes to
+	// a bytes.Buffer. It has convenience methods to split the accumulated buffer
+	// on newlines.
+	Buffer = ztest.Buffer
+)

zaptest/writer_test.go

@@ -21,52 +21,12 @@
 package zaptest
 
 import (
-	"bufio"
 	"errors"
-	"os"
-	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
-func readCode(t testing.TB, fname string) []string {
-	f, err := os.Open(fname)
-	require.NoError(t, err, "Failed to read %s.", fname)
-	defer func() {
-		require.NoError(t, f.Close(), "Error closing file %s.", fname)
-	}()
-
-	var lines []string
-	s := bufio.NewScanner(f)
-	for s.Scan() {
-		l := s.Text()
-		if len(l) == 0 {
-			continue
-		}
-		if strings.HasPrefix(l, "//") {
-			continue
-		}
-		if strings.HasPrefix(l, "package ") {
-			continue
-		}
-		lines = append(lines, l)
-	}
-	return lines
-}
-
-func TestCopiedCodeInSync(t *testing.T) {
-	// Until we drop Go 1.8 support, we need to keep a near-exact copy of the
-	// ztest package's WriteSyncer test spies in zaptest. This test ensures that
-	// the two files stay in sync.
-	assert.Equal(t,
-		readCode(t, "../internal/ztest/writer.go"),
-		readCode(t, "writer.go"),
-		"Writer spy implementations in zaptest and internal/ztest should be identical.",
-	)
-}
-
 func TestSyncer(t *testing.T) {
 	err := errors.New("sentinel")
 	s := &Syncer{}