Use go.uber.org/multierr (uber-go#458)

This drops zap's custom multierror implementation in favor of
go.uber.org/multierr.

Performance should be the same because we're relying on `Append`, which
short circuits in the no-error case.

Makefile

@@ -3,7 +3,7 @@ export GO15VENDOREXPERIMENT=1
 BENCH_FLAGS ?= -cpuprofile=cpu.pprof -memprofile=mem.pprof -benchmem
 PKGS ?= $(shell glide novendor)
 # Many Go tools take file globs or directories as arguments instead of packages.
-PKG_FILES ?= *.go zapcore benchmarks buffer zapgrpc zaptest zaptest/observer internal/bufferpool internal/exit internal/multierror internal/color
+PKG_FILES ?= *.go zapcore benchmarks buffer zapgrpc zaptest zaptest/observer internal/bufferpool internal/exit internal/color
 
 # The linting tools evolve with each Go version, so run them only on the latest
 # stable release.

glide.yaml

@@ -3,6 +3,8 @@ license: MIT
 import:
 - package: go.uber.org/atomic
   version: ^1
+- package: go.uber.org/multierr
+  version: ^1
 testImport:
 - package: github.com/satori/go.uuid
 - package: github.com/sirupsen/logrus

sugar.go

@@ -23,8 +23,9 @@ package zap
 import (
 	"fmt"
 
-	"go.uber.org/zap/internal/multierror"
 	"go.uber.org/zap/zapcore"
+
+	"go.uber.org/multierr"
 )
 
 const (
@@ -286,9 +287,9 @@ func (p invalidPair) MarshalLogObject(enc zapcore.ObjectEncoder) error {
 type invalidPairs []invalidPair
 
 func (ps invalidPairs) MarshalLogArray(enc zapcore.ArrayEncoder) error {
-	var errs multierror.Error
+	var err error
 	for i := range ps {
-		errs = errs.Append(enc.AppendObject(ps[i]))
+		err = multierr.Append(err, enc.AppendObject(ps[i]))
 	}
-	return errs.AsError()
+	return err
 }

writer.go

@@ -24,8 +24,9 @@ import (
 	"io/ioutil"
 	"os"
 
-	"go.uber.org/zap/internal/multierror"
 	"go.uber.org/zap/zapcore"
+
+	"go.uber.org/multierr"
 )
 
 // Open is a high-level wrapper that takes a variadic number of paths, opens or
@@ -46,7 +47,7 @@ func Open(paths ...string) (zapcore.WriteSyncer, func(), error) {
 }
 
 func open(paths []string) ([]zapcore.WriteSyncer, func(), error) {
-	var errs multierror.Error
+	var openErr error
 	writers := make([]zapcore.WriteSyncer, 0, len(paths))
 	files := make([]*os.File, 0, len(paths))
 	close := func() {
@@ -66,16 +67,16 @@ func open(paths []string) ([]zapcore.WriteSyncer, func(), error) {
 			continue
 		}
 		f, err := os.OpenFile(path, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
-		errs = errs.Append(err)
+		openErr = multierr.Append(openErr, err)
 		if err == nil {
 			writers = append(writers, f)
 			files = append(files, f)
 		}
 	}
 
-	if err := errs.AsError(); err != nil {
+	if openErr != nil {
 		close()
-		return writers, nil, err
+		return writers, nil, openErr
 	}
 
 	return writers, close, nil

zapcore/entry.go

@@ -28,7 +28,8 @@ import (
 
 	"go.uber.org/zap/internal/bufferpool"
 	"go.uber.org/zap/internal/exit"
-	"go.uber.org/zap/internal/multierror"
+
+	"go.uber.org/multierr"
 )
 
 var (
@@ -209,12 +210,12 @@ func (ce *CheckedEntry) Write(fields ...Field) {
 	}
 	ce.dirty = true
 
-	var errs multierror.Error
+	var err error
 	for i := range ce.cores {
-		errs = errs.Append(ce.cores[i].Write(ce.Entry, fields))
+		err = multierr.Append(err, ce.cores[i].Write(ce.Entry, fields))
 	}
 	if ce.ErrorOutput != nil {
-		if err := errs.AsError(); err != nil {
+		if err != nil {
 			fmt.Fprintf(ce.ErrorOutput, "%v write error: %v\n", time.Now(), err)
 			ce.ErrorOutput.Sync()
 		}

zapcore/hook.go

@@ -20,7 +20,7 @@
 
 package zapcore
 
-import "go.uber.org/zap/internal/multierror"
+import "go.uber.org/multierr"
 
 type hooked struct {
 	Core
@@ -60,9 +60,9 @@ func (h *hooked) With(fields []Field) Core {
 func (h *hooked) Write(ent Entry, _ []Field) error {
 	// Since our downstream had a chance to register itself directly with the
 	// CheckedMessage, we don't need to call it here.
-	var errs multierror.Error
+	var err error
 	for i := range h.funcs {
-		errs = errs.Append(h.funcs[i](ent))
+		err = multierr.Append(err, h.funcs[i](ent))
 	}
-	return errs.AsError()
+	return err
 }

zapcore/json_encoder_impl_test.go

@@ -31,9 +31,9 @@ import (
 	"time"
 
 	"go.uber.org/zap/internal/bufferpool"
-	"go.uber.org/zap/internal/multierror"
 
 	"github.com/stretchr/testify/assert"
+	"go.uber.org/multierr"
 )
 
 func TestJSONClone(t *testing.T) {
@@ -370,12 +370,12 @@ func (t turducken) MarshalLogObject(enc ObjectEncoder) error {
 type turduckens int
 
 func (t turduckens) MarshalLogArray(enc ArrayEncoder) error {
-	var errs multierror.Error
+	var err error
 	tur := turducken{}
 	for i := 0; i < int(t); i++ {
-		errs = errs.Append(enc.AppendObject(tur))
+		err = multierr.Append(err, enc.AppendObject(tur))
 	}
-	return errs.AsError()
+	return err
 }
 
 type loggable struct{ bool }

zapcore/tee.go

@@ -20,7 +20,7 @@
 
 package zapcore
 
-import "go.uber.org/zap/internal/multierror"
+import "go.uber.org/multierr"
 
 type multiCore []Core
 
@@ -65,17 +65,17 @@ func (mc multiCore) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
 }
 
 func (mc multiCore) Write(ent Entry, fields []Field) error {
-	var errs multierror.Error
+	var err error
 	for i := range mc {
-		errs = errs.Append(mc[i].Write(ent, fields))
+		err = multierr.Append(err, mc[i].Write(ent, fields))
 	}
-	return errs.AsError()
+	return err
 }
 
 func (mc multiCore) Sync() error {
-	var errs multierror.Error
+	var err error
 	for i := range mc {
-		errs = errs.Append(mc[i].Sync())
+		err = multierr.Append(err, mc[i].Sync())
 	}
-	return errs.AsError()
+	return err
 }

zapcore/write_syncer.go

@@ -24,7 +24,7 @@ import (
 	"io"
 	"sync"
 
-	"go.uber.org/zap/internal/multierror"
+	"go.uber.org/multierr"
 )
 
 // A WriteSyncer is an io.Writer that can also flush any buffered data. Note
@@ -100,24 +100,24 @@ func NewMultiWriteSyncer(ws ...WriteSyncer) WriteSyncer {
 // the smallest number is returned even though Write() is called on
 // all of them.
 func (ws multiWriteSyncer) Write(p []byte) (int, error) {
-	var errs multierror.Error
+	var writeErr error
 	nWritten := 0
 	for _, w := range ws {
 		n, err := w.Write(p)
-		errs = errs.Append(err)
+		writeErr = multierr.Append(writeErr, err)
 		if nWritten == 0 && n != 0 {
 			nWritten = n
 		} else if n < nWritten {
 			nWritten = n
 		}
 	}
-	return nWritten, errs.AsError()
+	return nWritten, writeErr
 }
 
 func (ws multiWriteSyncer) Sync() error {
-	var errs multierror.Error
+	var err error
 	for _, w := range ws {
-		errs = errs.Append(w.Sync())
+		err = multierr.Append(err, w.Sync())
 	}
-	return errs.AsError()
+	return err
 }