slog support + Groups (#52)

Dean Karn · web-flow · commit d3a738a8e3ac · 2023-08-15T19:46:27.000-07:00
diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
@@ -8,7 +8,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.18.x]
+        go-version: [1.18.x, 1.21.x]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
@@ -32,7 +32,7 @@ jobs:
         run: go test -race -covermode=atomic -coverprofile="profile.cov" ./...
 
       - name: Send Coverage
-        if: matrix.os == 'ubuntu-latest' && matrix.go-version == '1.18.x'
+        if: matrix.os == 'ubuntu-latest' && matrix.go-version == '1.21.x'
         uses: shogo82148/actions-goveralls@v1
         with:
           path-to-profile: profile.cov
@@ -43,9 +43,9 @@ jobs:
     steps:
       - uses: actions/setup-go@v3
         with:
-          go-version: 1.18.x
+          go-version: 1.21.x
       - uses: actions/checkout@v3
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v3
         with:
-          version: v1.46.2
+          version: latest
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [8.1.0] - 2023-08-16
+### Added
+- log.G as shorthand for adding a set of Grouped fields. This ability has always been present but is now fully supported in the default logger and with helper function for ease of use.
+- slog support added in Go 1.21+ both to use as an slog.Handler or redirect.
+
+### Fixed
+- errors.Chain handling from default withErrorFn handler after dep upgrade.
+
+## [8.0.2] - 2023-06-22
+### Fixed
+- Corrected removal of default logger upon registering a custom one.
+
 ## [8.0.1] - 2022-06-23
 ### Fixed
 - Handling un-hashable tag values during dedupe process.
@@ -30,6 +42,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Removed ability to remove individual log levels externally; RemoveHandler+AddHandler can do the same.
 
 
-[Unreleased]: https://github.com/go-playground/log/compare/v8.0.1...HEAD
+[Unreleased]: https://github.com/go-playground/log/compare/v8.1.0...HEAD
+[8.1.0]: https://github.com/go-playground/log/compare/v8.0.2...v8.1.0
+[8.0.2]: https://github.com/go-playground/log/compare/v8.0.1...v8.0.2
 [8.0.1]: https://github.com/go-playground/log/compare/v8.0.0...v8.0.1
 [8.0.0]: https://github.com/go-playground/log/compare/v7.0.2...v8.0.0
diff --git a/README.md b/README.md
@@ -1,5 +1,5 @@
 ## log
-<img align="center" src="https://raw.githubusercontent.com/go-playground/log/master/logo.png">![Project status](https://img.shields.io/badge/version-8.0.1-green.svg)
+<img align="center" src="https://raw.githubusercontent.com/go-playground/log/master/logo.png">![Project status](https://img.shields.io/badge/version-8.1.0-green.svg)
 [![Test](https://github.com/go-playground/log/actions/workflows/go.yml/badge.svg)](https://github.com/go-playground/log/actions/workflows/go.yml)
 [![Coverage Status](https://coveralls.io/repos/github/go-playground/log/badge.svg?branch=master)](https://coveralls.io/github/go-playground/log?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/github.com/go-playground/log)](https://goreportcard.com/report/github.com/go-playground/log)
@@ -152,9 +152,19 @@ func main() {
 	// logging with fields can be used with any of the above
 	log.WithField("key", "value").Info("test info")
 }
-
 ```
 
+#### Go 1.21+ slog compatibility
+
+There is a compatibility layer for slog, which allows redirecting slog to this logger and ability to output to an slog.Handler+.
+
+| type                                        | Definition                                                                                                                                                                          |
+|---------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| [Handler](_examples/slog/hanlder/main.go)   | This example demonstrates how to redirect the std log and slog to this logger by using it as an slog.Handler.                                                                       |
+| [Redirect](_examples/slog/redirect/main.go) | This example demonstrates how to redirect the std log and slog to this logger and output back out to any slog.Handler, as well as any other handler(s) registered with this logger. |
+
+```go
+
 Log Level Definitions
 ---------------------
 
diff --git a/_examples/slog/handler/main.go b/_examples/slog/handler/main.go
@@ -0,0 +1,20 @@
+//go:build go1.21
+// +build go1.21
+
+package main
+
+import (
+	"github.com/go-playground/log/v8"
+	stdlog "log"
+	"log/slog"
+)
+
+func main() {
+
+	// This example demonstrates how to redirect the std log and slog to this logger by using it as
+	// an slog.Handler.
+	log.RedirectGoStdLog(true)
+	log.WithFields(log.G("grouped", log.F("key", "value"))).Debug("test")
+	stdlog.Println("test stdlog")
+	slog.Info("test slog", slog.Group("group", "key", "value"))
+}
diff --git a/_examples/slog/redirect/main.go b/_examples/slog/redirect/main.go
@@ -0,0 +1,24 @@
+//go:build go1.21
+// +build go1.21
+
+package main
+
+import (
+	"github.com/go-playground/log/v8"
+	slogredirect "github.com/go-playground/log/v8/handlers/slog"
+	stdlog "log"
+	"log/slog"
+	"os"
+)
+
+func main() {
+
+	// This example demonstrates how to redirect the std log and slog to this logger and output back out to any
+	// slog.Handler, as well as any other handler(s) registered with this logger.
+	log.AddHandler(slogredirect.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
+		ReplaceAttr: slogredirect.ReplaceAttrFn, // for custom log level output
+	})), log.AllLevels...)
+	log.WithFields(log.G("grouped", log.F("key", "value"))).Debug("test")
+	stdlog.Println("test stdlog")
+	slog.Info("test slog", slog.Group("group", "key", "value"))
+}
diff --git a/benchmarks/benchmark_test.go b/benchmarks/benchmark_test.go
@@ -7,7 +7,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/go-playground/log/v8"
+	log "github.com/go-playground/log/v8"
 	"github.com/go-playground/log/v8/handlers/json"
 )
 
diff --git a/default_logger.go b/default_logger.go
@@ -72,49 +72,73 @@ func (c *Logger) Log(e Entry) {
 	buff.B = append(buff.B, space)
 	buff.B = append(buff.B, e.Message...)
 
-	for _, f := range e.Fields {
-		buff.B = append(buff.B, space)
-		buff.B = append(buff.B, f.Key...)
-		buff.B = append(buff.B, equals)
+	c.addFields("", buff, e.Fields)
+	buff.B = append(buff.B, newLine)
+
+	c.m.Lock()
+	_, _ = c.writer.Write(buff.B)
+	c.m.Unlock()
+
+	BytePool().Put(buff)
+}
+
+func (c *Logger) addFields(prefix string, buff *Buffer, fields []Field) {
+	for _, f := range fields {
 
 		switch t := f.Value.(type) {
 		case string:
+			printKey(buff, prefix+f.Key)
 			buff.B = append(buff.B, t...)
 		case int:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendInt(buff.B, int64(t), base10)
 		case int8:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendInt(buff.B, int64(t), base10)
 		case int16:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendInt(buff.B, int64(t), base10)
 		case int32:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendInt(buff.B, int64(t), base10)
 		case int64:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendInt(buff.B, t, base10)
 		case uint:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendUint(buff.B, uint64(t), base10)
 		case uint8:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendUint(buff.B, uint64(t), base10)
 		case uint16:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendUint(buff.B, uint64(t), base10)
 		case uint32:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendUint(buff.B, uint64(t), base10)
 		case uint64:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendUint(buff.B, t, base10)
 		case float32:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendFloat(buff.B, float64(t), 'f', -1, 32)
 		case float64:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendFloat(buff.B, t, 'f', -1, 64)
 		case bool:
+			printKey(buff, prefix+f.Key)
 			buff.B = strconv.AppendBool(buff.B, t)
+		case []Field:
+			c.addFields(prefix+f.Key+".", buff, t)
 		default:
+			printKey(buff, prefix+f.Key)
 			buff.B = append(buff.B, fmt.Sprintf(v, f.Value)...)
 		}
 	}
-	buff.B = append(buff.B, newLine)
-
-	c.m.Lock()
-	_, _ = c.writer.Write(buff.B)
-	c.m.Unlock()
+}
 
-	BytePool().Put(buff)
+func printKey(buff *Buffer, key string) {
+	buff.B = append(buff.B, space)
+	buff.B = append(buff.B, key...)
+	buff.B = append(buff.B, equals)
 }
diff --git a/errors.go b/errors.go
@@ -102,13 +102,11 @@ func formatLink(l *errors.Link, b []byte) []byte {
 	b = extractSource(b, l.Source)
 	if l.Prefix != "" {
 		b = append(b, l.Prefix...)
-	}
 
-	if _, ok := l.Err.(errors.Chain); !ok {
-		if l.Prefix != "" {
+		if l.Err != nil {
 			b = append(b, ": "...)
+			b = append(b, l.Err.Error()...)
 		}
-		b = append(b, l.Err.Error()...)
 	}
 	return b
 }
diff --git a/go.mod b/go.mod
@@ -3,9 +3,9 @@ module github.com/go-playground/log/v8
 go 1.18
 
 require (
-	github.com/go-playground/errors/v5 v5.2.3
-	github.com/go-playground/pkg/v5 v5.6.0
-	golang.org/x/term v0.0.0-20220526004731-065cf7ba2467
+	github.com/go-playground/errors/v5 v5.3.1
+	github.com/go-playground/pkg/v5 v5.21.2
+	golang.org/x/term v0.11.0
 )
 
-require golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 // indirect
+require golang.org/x/sys v0.11.0 // indirect
diff --git a/go.sum b/go.sum
@@ -1,8 +1,8 @@
-github.com/go-playground/errors/v5 v5.2.3 h1:RPxaFHgJZjgk/OFkUcfytJgRQKRINLtueVxgOdnfPpg=
-github.com/go-playground/errors/v5 v5.2.3/go.mod h1:DincxRGwraWmq39TZDqtnOtHGOJ+AbNbO0OmBzX6MLw=
-github.com/go-playground/pkg/v5 v5.6.0 h1:97YpRFzIcS5NFP2Uzxj8cPYz4zTuwweyXADYcA1KfUQ=
-github.com/go-playground/pkg/v5 v5.6.0/go.mod h1:TvZ2nNtNh6VfoNteY9ApA2BXt1ZwJliFZ4hzPAwLS9Y=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 h1:SrN+KX8Art/Sf4HNj6Zcz06G7VEz+7w9tdXTPOZ7+l4=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.0.0-20220526004731-065cf7ba2467 h1:CBpWXWQpIRjzmkkA+M7q9Fqnwd2mZr3AFqexg8YTfoM=
-golang.org/x/term v0.0.0-20220526004731-065cf7ba2467/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+github.com/go-playground/errors/v5 v5.3.1 h1:J2qU+9Whg863g3SATXKSJyFA91Zz85pYD3+obr5Oodk=
+github.com/go-playground/errors/v5 v5.3.1/go.mod h1:LcLhmzQ/RuEntAs9r38NSV+xtbHffhMx/1yuuEroc7M=
+github.com/go-playground/pkg/v5 v5.21.2 h1:DgVr88oMI3pfMFkEN9E6hp9YGG8NHc+019LRJfnUOfU=
+github.com/go-playground/pkg/v5 v5.21.2/go.mod h1:UgHNntEQnMJSygw2O2RQ3LAB0tprx81K90c/pOKh7cU=
+golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
+golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.11.0 h1:F9tnn/DA/Im8nCwm+fX+1/eBwi4qFjRT++MhtVC4ZX0=
+golang.org/x/term v0.11.0/go.mod h1:zC9APTIj3jG3FdV/Ons+XE1riIZXG4aZ4GTHiPZJPIU=
diff --git a/handlers/json/json.go b/handlers/json/json.go
@@ -6,7 +6,7 @@ import (
 	"io"
 	"sync"
 
-	"github.com/go-playground/log/v8"
+	log "github.com/go-playground/log/v8"
 )
 
 // Handler implementation.
diff --git a/handlers/json/json_test.go b/handlers/json/json_test.go
@@ -5,7 +5,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/go-playground/log/v8"
+	log "github.com/go-playground/log/v8"
 )
 
 func TestJSONLogger(t *testing.T) {
diff --git a/handlers/slog/slog_redirect.go b/handlers/slog/slog_redirect.go
@@ -0,0 +1,59 @@
+//go:build go1.21
+// +build go1.21
+
+package slog
+
+import (
+	"context"
+	log "github.com/go-playground/log/v8"
+	"log/slog"
+)
+
+// Handler implementation.
+type Handler struct {
+	handler slog.Handler
+}
+
+// New handler wraps an slog.Handler for log output.
+//
+// Calling this function automatically calls the slog.RedirectGoStdLog function in order to intercept and forward
+// the Go standard library log output to this handler.
+func New(handler slog.Handler) *Handler {
+	log.RedirectGoStdLog(true)
+	return &Handler{handler: handler}
+}
+
+// Log handles the log entry
+func (h *Handler) Log(e log.Entry) {
+	r := slog.NewRecord(e.Timestamp, slog.Level(e.Level), e.Message, 0)
+	r.AddAttrs(h.convertFields(e.Fields)...)
+	_ = h.handler.Handle(context.Background(), r)
+}
+
+func (h *Handler) convertFields(fields []log.Field) []slog.Attr {
+	attrs := make([]slog.Attr, 0, len(fields))
+	for _, f := range fields {
+		switch t := f.Value.(type) {
+		case []log.Field:
+			a := h.convertFields(t)
+			arr := make([]any, 0, len(a))
+			for _, v := range a {
+				arr = append(arr, v)
+			}
+			attrs = append(attrs, slog.Group(f.Key, arr...))
+		default:
+			attrs = append(attrs, slog.Any(f.Key, f.Value))
+		}
+	}
+	return attrs
+}
+
+// ReplaceAttrFn can be used with slog.HandlerOptions to replace attributes.
+// This function replaces the "level" attribute to get the custom log levels of this package.
+var ReplaceAttrFn = func(groups []string, a slog.Attr) slog.Attr {
+	if a.Key == slog.LevelKey {
+		level := log.Level(a.Value.Any().(slog.Level))
+		a.Value = slog.StringValue(level.String())
+	}
+	return a
+}
diff --git a/handlers/slog/slog_redirect_test.go b/handlers/slog/slog_redirect_test.go
@@ -0,0 +1,46 @@
+//go:build go1.21
+// +build go1.21
+
+package slog
+
+import (
+	"bytes"
+	"encoding/json"
+	"github.com/go-playground/log/v8"
+	"log/slog"
+	"strings"
+	"testing"
+	"testing/slogtest"
+)
+
+func TestSlogRedirect(t *testing.T) {
+	var buff bytes.Buffer
+	log.AddHandler(New(slog.NewJSONHandler(&buff, &slog.HandlerOptions{
+		ReplaceAttr: ReplaceAttrFn, // for custom log level output
+	})), log.AllLevels...)
+	h := slog.Default().Handler()
+
+	results := func() []map[string]any {
+		var ms []map[string]any
+		for _, line := range bytes.Split(buff.Bytes(), []byte{'\n'}) {
+			if len(line) == 0 {
+				continue
+			}
+			var m map[string]any
+			if err := json.Unmarshal(line, &m); err != nil {
+				panic(err) // In a real test, use t.Fatal.
+			}
+			ms = append(ms, m)
+		}
+		return ms
+	}
+	err := slogtest.TestHandler(h, results)
+	if err != nil {
+		// if a single error and is time key errors, is ok this logger always sets that.
+		// sad this its the only way to hook into these errors because none of concrete and
+		// Joined errors has no way to reach into them when not.
+		if strings.Count(err.Error(), "\n") != 0 || !strings.Contains(err.Error(), "unexpected key \"time\": a Handler should ignore a zero Record.Time") {
+			t.Fatal(err)
+		}
+	}
+}
diff --git a/log.go b/log.go
diff --git a/log_pre_1.21.go b/log_pre_1.21.go
diff --git a/log_test.go b/log_test.go
diff --git a/slog.go b/slog.go

Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ import (`
`7`	`7`	`"testing"`
`8`	`8`	`"time"`
`9`	`9`
`10`		`- "github.com/go-playground/log/v8"`
	`10`	`+ log "github.com/go-playground/log/v8"`
`11`	`11`	`"github.com/go-playground/log/v8/handlers/json"`
`12`	`12`	`)`
`13`	`13`
Original file line number	Diff line number	Diff line change
`@@ -102,13 +102,11 @@ func formatLink(l *errors.Link, b []byte) []byte {`
`102`	`102`	`b = extractSource(b, l.Source)`
`103`	`103`	`if l.Prefix != "" {`
`104`	`104`	`b = append(b, l.Prefix...)`
`105`		`- }`
`106`	`105`
`107`		`- if _, ok := l.Err.(errors.Chain); !ok {`
`108`		`- if l.Prefix != "" {`
	`106`	`+ if l.Err != nil {`
`109`	`107`	`b = append(b, ": "...)`
	`108`	`+ b = append(b, l.Err.Error()...)`
`110`	`109`	`}`
`111`		`- b = append(b, l.Err.Error()...)`
`112`	`110`	`}`
`113`	`111`	`return b`
`114`	`112`	`}`