Add fuzz test for core Logger implementation

Author: kuujo

framework.go

@@ -4,15 +4,31 @@
 
 package dazl
 
+import (
+	"io"
+	"os"
+)
+
 func Register(framework Framework) {
 	var config loggingConfig
 	if err := load(&config); err != nil {
 		panic(err)
-	} else if err := configure(framework, config); err != nil {
+	} else if err := configure(framework, config, open); err != nil {
 		panic(err)
 	}
 }
 
+func open(path string) (io.Writer, error) {
+	switch path {
+	case "stdout":
+		return os.Stdout, nil
+	case "stderr":
+		return os.Stderr, nil
+	default:
+		return os.OpenFile(path, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
+	}
+}
+
 type Framework interface {
 	Name() string
 }

go.mod

@@ -3,13 +3,15 @@ module github.com/atomix/dazl
 go 1.19
 
 require (
+	github.com/AdaLogics/go-fuzz-headers v0.0.0-20230106234847-43070de90fa1
 	github.com/golang/mock v1.6.0
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/stretchr/testify v1.8.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
+	github.com/cyphar/filepath-securejoin v0.2.3 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 )

go.sum

@@ -1,3 +1,7 @@
+github.com/AdaLogics/go-fuzz-headers v0.0.0-20230106234847-43070de90fa1 h1:EKPd1INOIyr5hWOWhvpmQpY6tKjeG0hT1s3AMC/9fic=
+github.com/AdaLogics/go-fuzz-headers v0.0.0-20230106234847-43070de90fa1/go.mod h1:VzwV+t+dZ9j/H867F1M2ziD+yLHtB46oM35FxxMJ4d0=
+github.com/cyphar/filepath-securejoin v0.2.3 h1:YX6ebbZCZP7VkM3scTTokDgBL2TY741X51MTk3ycuNI=
+github.com/cyphar/filepath-securejoin v0.2.3/go.mod h1:aPGpWjXOXUn2NCNjFvBE6aRxGGx79pTxQpKOJNYHHl4=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

level.go

@@ -18,10 +18,10 @@ const (
 	WarnLevel
 	// ErrorLevel logs a message at error level
 	ErrorLevel
-	// FatalLevel logs a message, then calls os.Exit(1).
-	FatalLevel
 	// PanicLevel logs a message, then panics.
 	PanicLevel
+	// FatalLevel logs a message, then calls os.Exit(1).
+	FatalLevel
 )
 
 // Enabled indicates whether the log level is enabled
@@ -31,7 +31,7 @@ func (l Level) Enabled(level Level) bool {
 
 // String :
 func (l Level) String() string {
-	return [...]string{"", "debug", "info", "warn", "error", "fatal", "panic"}[l]
+	return [...]string{"", "debug", "info", "warn", "error", "panic", "fatal"}[l]
 }
 
 type levelConfig Level
@@ -50,10 +50,10 @@ func (c *levelConfig) UnmarshalText(text []byte) error {
 		*c = levelConfig(WarnLevel)
 	case ErrorLevel.String():
 		*c = levelConfig(ErrorLevel)
-	case FatalLevel.String():
-		*c = levelConfig(FatalLevel)
 	case PanicLevel.String():
 		*c = levelConfig(PanicLevel)
+	case FatalLevel.String():
+		*c = levelConfig(FatalLevel)
 	default:
 		*c = levelConfig(EmptyLevel)
 	}

level_test.go

@@ -19,10 +19,10 @@ func TestLevel(t *testing.T) {
 	assert.True(t, WarnLevel.Enabled(WarnLevel))
 	assert.False(t, ErrorLevel.Enabled(WarnLevel))
 	assert.True(t, ErrorLevel.Enabled(ErrorLevel))
-	assert.False(t, FatalLevel.Enabled(ErrorLevel))
-	assert.True(t, FatalLevel.Enabled(FatalLevel))
-	assert.False(t, PanicLevel.Enabled(FatalLevel))
+	assert.False(t, PanicLevel.Enabled(ErrorLevel))
 	assert.True(t, PanicLevel.Enabled(PanicLevel))
+	assert.False(t, FatalLevel.Enabled(PanicLevel))
+	assert.True(t, FatalLevel.Enabled(FatalLevel))
 }
 
 const testLevel = "info"

logger.go

@@ -6,7 +6,7 @@ package dazl
 
 import (
 	"fmt"
-	"os"
+	"io"
 	"runtime"
 	"strings"
 	"sync"
@@ -107,8 +107,8 @@ func getCallerPackage() (string, bool) {
 	return pkg, true
 }
 
-func configure(framework Framework, config loggingConfig) error {
-	context, err := newLoggingContext(framework, config)
+func configure(framework Framework, config loggingConfig, opener func(path string) (io.Writer, error)) error {
+	context, err := newLoggingContext(framework, config, opener)
 	if err != nil {
 		return err
 	}
@@ -230,7 +230,7 @@ func newLogger(context *loggingContext, parent *dazlLogger, name string) (*dazlL
 	return logger, nil
 }
 
-func newLoggingContext(framework Framework, config loggingConfig) (*loggingContext, error) {
+func newLoggingContext(framework Framework, config loggingConfig, opener func(path string) (io.Writer, error)) (*loggingContext, error) {
 	encoders := make(map[Encoding]Encoder)
 	if consoleEncodingFramework, ok := framework.(ConsoleEncodingFramework); ok {
 		encoder, err := configureConsoleEncoder(config.Encoders.Console, consoleEncodingFramework.ConsoleEncoder())
@@ -250,12 +250,14 @@ func newLoggingContext(framework Framework, config loggingConfig) (*loggingConte
 		framework: framework,
 		config:    config,
 		encoders:  encoders,
+		opener:    opener,
 	}, nil
 }
 
 type loggingContext struct {
 	framework Framework
 	config    loggingConfig
+	opener    func(path string) (io.Writer, error)
 	encoders  map[Encoding]Encoder
 	writers   sync.Map
 	mu        sync.Mutex
@@ -294,7 +296,11 @@ func (c *loggingContext) newWriter(name string) (Writer, error) {
 		if !ok {
 			return nil, fmt.Errorf("%s framework does not support %s encoding", c.framework.Name(), c.config.Writers.Stdout.Encoder)
 		}
-		return encoder.NewWriter(os.Stdout)
+		writer, err := c.opener("stdout")
+		if err != nil {
+			return nil, err
+		}
+		return encoder.NewWriter(writer)
 	case "stderr":
 		if c.config.Writers.Stderr == nil {
 			return nil, fmt.Errorf("'%s' writer is not configured", name)
@@ -303,21 +309,25 @@ func (c *loggingContext) newWriter(name string) (Writer, error) {
 		if !ok {
 			return nil, fmt.Errorf("%s framework does not support %s encoding", c.framework.Name(), c.config.Writers.Stderr.Encoder)
 		}
-		return encoder.NewWriter(os.Stderr)
+		writer, err := c.opener("stderr")
+		if err != nil {
+			return nil, err
+		}
+		return encoder.NewWriter(writer)
 	default:
 		config, ok := c.config.Writers.getFile(name)
 		if !ok {
 			return nil, fmt.Errorf("'%s' writer is not configured", name)
 		}
-		file, err := os.OpenFile(config.Path, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
+		writer, err := c.opener(config.Path)
 		if err != nil {
 			return nil, err
 		}
 		encoder, ok := c.encoders[config.Encoder]
 		if !ok {
 			return nil, fmt.Errorf("%s framework does not support %s encoding", c.framework.Name(), config.Encoder)
 		}
-		return encoder.NewWriter(file)
+		return encoder.NewWriter(writer)
 	}
 }