Support configurable delimiter for console encoder (#697)

It would be nice to have a configurable delimiter for console encoder, tab by default.

For our cases, we prefer to have space as element delimiter.

A custom console delimiter can be set through the `consoleSeparator` encoder configuration.

zapcore/console_encoder.go

@@ -56,6 +56,10 @@ type consoleEncoder struct {
 // encoder configuration, it will omit any element whose key is set to the empty
 // string.
 func NewConsoleEncoder(cfg EncoderConfig) Encoder {
+	if len(cfg.ConsoleSeparator) == 0 {
+		// Use a default delimiter of '\t' for backwards compatibility
+		cfg.ConsoleSeparator = "\t"
+	}
 	return consoleEncoder{newJSONEncoder(cfg, true)}
 }
 
@@ -94,15 +98,15 @@ func (c consoleEncoder) EncodeEntry(ent Entry, fields []Field) (*buffer.Buffer,
 	}
 	for i := range arr.elems {
 		if i > 0 {
-			line.AppendByte('\t')
+			line.AppendString(c.ConsoleSeparator)
 		}
 		fmt.Fprint(line, arr.elems[i])
 	}
 	putSliceEncoder(arr)
 
 	// Add the message itself.
 	if c.MessageKey != "" {
-		c.addTabIfNecessary(line)
+		c.addSeparatorIfNecessary(line)
 		line.AppendString(ent.Message)
 	}
 
@@ -134,14 +138,14 @@ func (c consoleEncoder) writeContext(line *buffer.Buffer, extra []Field) {
 		return
 	}
 
-	c.addTabIfNecessary(line)
+	c.addSeparatorIfNecessary(line)
 	line.AppendByte('{')
 	line.Write(context.buf.Bytes())
 	line.AppendByte('}')
 }
 
-func (c consoleEncoder) addTabIfNecessary(line *buffer.Buffer) {
+func (c consoleEncoder) addSeparatorIfNecessary(line *buffer.Buffer) {
 	if line.Len() > 0 {
-		line.AppendByte('\t')
+		line.AppendString(c.ConsoleSeparator)
 	}
 }

zapcore/console_encoder_test.go

@@ -0,0 +1,91 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+package zapcore_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	. "go.uber.org/zap/zapcore"
+)
+
+var (
+	testEntry = Entry{
+		LoggerName: "main",
+		Level:      InfoLevel,
+		Message:    `hello`,
+		Time:       _epoch,
+		Stack:      "fake-stack",
+		Caller:     EntryCaller{Defined: true, File: "foo.go", Line: 42},
+	}
+)
+
+func TestConsoleSeparator(t *testing.T) {
+	tests := []struct {
+		desc        string
+		separator   string
+		wantConsole string
+	}{
+		{
+			desc:        "space console separator",
+			separator:   " ",
+			wantConsole: "0 info main foo.go:42 hello\nfake-stack\n",
+		},
+		{
+			desc:        "default console separator",
+			separator:   "",
+			wantConsole: "0\tinfo\tmain\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc:        "tag console separator",
+			separator:   "\t",
+			wantConsole: "0\tinfo\tmain\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc:        "dash console separator",
+			separator:   "--",
+			wantConsole: "0--info--main--foo.go:42--hello\nfake-stack\n",
+		},
+	}
+
+	for _, tt := range tests {
+		console := NewConsoleEncoder(encoderTestEncoderConfig(tt.separator))
+		t.Run(tt.desc, func(t *testing.T) {
+			entry := testEntry
+			consoleOut, err := console.EncodeEntry(entry, nil)
+			if !assert.NoError(t, err) {
+				return
+			}
+			assert.Equal(
+				t,
+				tt.wantConsole,
+				consoleOut.String(),
+				"Unexpected console output",
+			)
+		})
+
+	}
+}
+
+func encoderTestEncoderConfig(separator string) EncoderConfig {
+	testEncoder := testEncoderConfig()
+	testEncoder.ConsoleSeparator = separator
+	return testEncoder
+}

zapcore/encoder.go

@@ -329,6 +329,9 @@ type EncoderConfig struct {
 	// Unlike the other primitive type encoders, EncodeName is optional. The
 	// zero value falls back to FullNameEncoder.
 	EncodeName NameEncoder `json:"nameEncoder" yaml:"nameEncoder"`
+	// Configures the field separator used by the console encoder. Defaults
+	// to tab.
+	ConsoleSeparator string `json:"consoleSeparator" yaml:"consoleSeparator"`
 }
 
 // ObjectEncoder is a strongly-typed, encoding-agnostic interface for adding a