Helper method to simplify passing Logger as io.Writer (#25)

* Make Logger comply with io.Writer

Alternative to #24

* Fixed SimpleRenderer

* Format message upon log entry creation

* Reorder fields

* Introduce AsWriter method

Author: fkorotkov

go.mod

@@ -4,6 +4,6 @@ go 1.14
 
 require (
 	github.com/stretchr/testify v1.6.1
-	golang.org/x/sys v0.0.0-20200817155316-9781c653f443
-	golang.org/x/text v0.3.3
+	golang.org/x/sys v0.0.0-20220928140112-f11e5e49a4ec
+	golang.org/x/text v0.3.7
 )

go.sum

@@ -7,8 +7,12 @@ github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 golang.org/x/sys v0.0.0-20200817155316-9781c653f443 h1:X18bCaipMcoJGm27Nv7zr4XYPKGUy92GtqboKC2Hxaw=
 golang.org/x/sys v0.0.0-20200817155316-9781c653f443/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20220928140112-f11e5e49a4ec h1:BkDtF2Ih9xZ7le9ndzTA7KJow28VbQW3odyk/8drmuI=
+golang.org/x/sys v0.0.0-20220928140112-f11e5e49a4ec/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

log_entry.go

@@ -52,23 +52,25 @@ func (entry *LogScopeFinished) GetScopes() []string {
 }
 
 type LogEntryMessage struct {
-	Level     LogLevel
-	format    string
-	arguments []interface{}
-	scopes    []string
+	Level   LogLevel
+	scopes  []string
+	message string
+	raw     bool
 }
 
-func NewLogEntryMessage(scopes []string, level LogLevel, format string, a ...interface{}) *LogEntryMessage {
+func NewLogEntryMessage(scopes []string, level LogLevel, format string, arguments ...interface{}) *LogEntryMessage {
 	return &LogEntryMessage{
-		Level:     level,
-		format:    format,
-		arguments: a,
-		scopes:    scopes,
+		Level:   level,
+		scopes:  scopes,
+		message: fmt.Sprintf(format, arguments...),
 	}
 }
 
 func (entry *LogEntryMessage) GetMessage() string {
-	return fmt.Sprintf(entry.format, entry.arguments...)
+	if entry.raw {
+		return entry.message
+	}
+	return entry.message + "\n"
 }
 
 func (entry *LogEntryMessage) GetScopes() []string {

logger.go

@@ -1,5 +1,7 @@
 package echelon
 
+import "io"
+
 type genericLogEntry struct {
 	LogStarted  *LogScopeStarted
 	LogFinished *LogScopeFinished
@@ -13,12 +15,26 @@ type LogRendered interface {
 }
 
 type Logger struct {
-	level          LogLevel
+	maxLogLevel    LogLevel
 	scopes         []string
 	entriesChannel chan *genericLogEntry
 	renderer       LogRendered
 }
 
+type loggerAsWriter struct {
+	logger *Logger
+	level  LogLevel
+}
+
+func (w *loggerAsWriter) Write(p []byte) (n int, err error) {
+	if w.logger.IsLogLevelEnabled(w.level) {
+		logEntryMessage := NewLogEntryMessage(w.logger.scopes, w.level, string(p))
+		logEntryMessage.raw = true
+		w.logger.entriesChannel <- &genericLogEntry{LogEntry: logEntryMessage}
+	}
+	return len(p), err
+}
+
 type FinishType int
 
 const (
@@ -29,7 +45,7 @@ const (
 
 func NewLogger(level LogLevel, renderer LogRendered) *Logger {
 	logger := &Logger{
-		level:          level,
+		maxLogLevel:    level,
 		entriesChannel: make(chan *genericLogEntry),
 		renderer:       renderer,
 	}
@@ -43,7 +59,7 @@ func (logger *Logger) Renderer() LogRendered {
 
 func (logger *Logger) Scoped(scope string) *Logger {
 	result := &Logger{
-		level:          logger.level,
+		maxLogLevel:    logger.maxLogLevel,
 		scopes:         append(logger.scopes, scope),
 		entriesChannel: logger.entriesChannel,
 	}
@@ -96,6 +112,10 @@ func (logger *Logger) Logf(level LogLevel, format string, args ...interface{}) {
 	}
 }
 
+func (logger *Logger) AsWriter(level LogLevel) io.Writer {
+	return &loggerAsWriter{logger: logger, level: level}
+}
+
 func (logger *Logger) Finish(success bool) {
 	var finishType FinishType
 
@@ -115,5 +135,5 @@ func (logger *Logger) FinishWithType(finishType FinishType) {
 }
 
 func (logger *Logger) IsLogLevelEnabled(level LogLevel) bool {
-	return level <= logger.level
+	return level <= logger.maxLogLevel
 }

renderers/interactive.go

@@ -74,7 +74,7 @@ func (r *InteractiveRenderer) RenderScopeFinished(entry *echelon.LogScopeFinishe
 }
 
 func (r *InteractiveRenderer) RenderMessage(entry *echelon.LogEntryMessage) {
-	findScopedNode(entry.GetScopes(), r).AppendDescription(entry.GetMessage() + "\n")
+	findScopedNode(entry.GetScopes(), r).AppendDescription(entry.GetMessage())
 }
 
 func (r *InteractiveRenderer) StartDrawing() {

renderers/simple.go

@@ -46,7 +46,7 @@ func (r SimpleRenderer) RenderScopeStarted(entry *echelon.LogScopeStarted) {
 	r.startTimes[timeKey] = time.Now()
 	lastScope := scopes[level-1]
 	message := terminal.GetColoredText(r.colors.NeutralColor, fmt.Sprintf("Started %s", quotedIfNeeded(lastScope)))
-	r.RenderRawMessage(message)
+	r.RenderRawMessage(message + "\n")
 }
 
 func (r SimpleRenderer) RenderScopeFinished(entry *echelon.LogScopeFinished) {
@@ -68,15 +68,15 @@ func (r SimpleRenderer) RenderScopeFinished(entry *echelon.LogScopeFinished) {
 	case echelon.FinishTypeSucceeded:
 		message := fmt.Sprintf("%s succeeded in %s!", quotedIfNeeded(lastScope), formatedDuration)
 		coloredMessage := terminal.GetColoredText(r.colors.SuccessColor, message)
-		r.RenderRawMessage(coloredMessage)
+		r.RenderRawMessage(coloredMessage + "\n")
 	case echelon.FinishTypeFailed:
 		message := fmt.Sprintf("%s failed in %s!", quotedIfNeeded(lastScope), formatedDuration)
 		coloredMessage := terminal.GetColoredText(r.colors.FailureColor, message)
-		r.RenderRawMessage(coloredMessage)
+		r.RenderRawMessage(coloredMessage + "\n")
 	case echelon.FinishTypeSkipped:
 		message := fmt.Sprintf("%s skipped in %s!", quotedIfNeeded(lastScope), formatedDuration)
 		coloredMessage := terminal.GetColoredText(r.colors.NeutralColor, message)
-		r.RenderRawMessage(coloredMessage)
+		r.RenderRawMessage(coloredMessage + "\n")
 	}
 }
 
@@ -85,7 +85,7 @@ func (r SimpleRenderer) RenderMessage(entry *echelon.LogEntryMessage) {
 }
 
 func (r SimpleRenderer) RenderRawMessage(message string) {
-	_, _ = r.out.Write([]byte(message + "\n"))
+	_, _ = r.out.Write([]byte(message))
 }
 
 func (r SimpleRenderer) ScopeHasStarted(scopes []string) bool {