Improve stderr logging for PostCSS and simlilar

Fixes #7584

common/loggers/loggers.go

@@ -39,6 +39,23 @@ func init() {
 	jww.SetLogListeners(jww.LogCounter(GlobalErrorCounter, jww.LevelError))
 }
 
+func LoggerToWriterWithPrefix(logger *log.Logger, prefix string) io.Writer {
+	return prefixWriter{
+		logger: logger,
+		prefix: prefix,
+	}
+}
+
+type prefixWriter struct {
+	logger *log.Logger
+	prefix string
+}
+
+func (w prefixWriter) Write(p []byte) (n int, err error) {
+	w.logger.Printf("%s: %s", w.prefix, p)
+	return len(p), nil
+}
+
 // Logger wraps a *loggers.Logger and some other related logging state.
 type Logger struct {
 	*jww.Notepad
@@ -93,17 +110,32 @@ func NewLogger(stdoutThreshold, logThreshold jww.Threshold, outHandle, logHandle
 
 // NewDebugLogger is a convenience function to create a debug logger.
 func NewDebugLogger() *Logger {
-	return newBasicLogger(jww.LevelDebug)
+	return NewBasicLogger(jww.LevelDebug)
 }
 
 // NewWarningLogger is a convenience function to create a warning logger.
 func NewWarningLogger() *Logger {
-	return newBasicLogger(jww.LevelWarn)
+	return NewBasicLogger(jww.LevelWarn)
+}
+
+// NewInfoLogger is a convenience function to create a info logger.
+func NewInfoLogger() *Logger {
+	return NewBasicLogger(jww.LevelInfo)
 }
 
 // NewErrorLogger is a convenience function to create an error logger.
 func NewErrorLogger() *Logger {
-	return newBasicLogger(jww.LevelError)
+	return NewBasicLogger(jww.LevelError)
+}
+
+// NewBasicLogger creates a new basic logger writing to Stdout.
+func NewBasicLogger(t jww.Threshold) *Logger {
+	return newLogger(t, jww.LevelError, os.Stdout, ioutil.Discard, false)
+}
+
+// NewBasicLoggerForWriter creates a new basic logger writing to w.
+func NewBasicLoggerForWriter(t jww.Threshold, w io.Writer) *Logger {
+	return newLogger(t, jww.LevelError, w, ioutil.Discard, false)
 }
 
 var (
@@ -215,7 +247,3 @@ func newLogger(stdoutThreshold, logThreshold jww.Threshold, outHandle, logHandle
 		errors:       errorBuff,
 	}
 }
-
-func newBasicLogger(t jww.Threshold) *Logger {
-	return newLogger(t, jww.LevelError, os.Stdout, ioutil.Discard, false)
-}

common/loggers/loggers_test.go

@@ -14,6 +14,9 @@
 package loggers
 
 import (
+	"bytes"
+	"fmt"
+	"log"
 	"testing"
 
 	qt "github.com/frankban/quicktest"
@@ -30,3 +33,17 @@ func TestLogger(t *testing.T) {
 	c.Assert(l.ErrorCounter.Count(), qt.Equals, uint64(2))
 
 }
+
+func TestLoggerToWriterWithPrefix(t *testing.T) {
+	c := qt.New(t)
+
+	var b bytes.Buffer
+
+	logger := log.New(&b, "", 0)
+
+	w := LoggerToWriterWithPrefix(logger, "myprefix")
+
+	fmt.Fprint(w, "Hello Hugo!")
+
+	c.Assert(b.String(), qt.Equals, "myprefix: Hello Hugo!\n")
+}

hugolib/resource_chain_babel_test.go

@@ -14,12 +14,15 @@
 package hugolib
 
 import (
+	"bytes"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"runtime"
 	"testing"
 
+	jww "github.com/spf13/jwalterweatherman"
+
 	"github.com/gohugoio/hugo/htesting"
 
 	"github.com/spf13/viper"
@@ -80,10 +83,13 @@ class Car {
 	c.Assert(err, qt.IsNil)
 	defer clean()
 
+	var logBuf bytes.Buffer
+	logger := loggers.NewBasicLoggerForWriter(jww.LevelInfo, &logBuf)
+
 	v := viper.New()
 	v.Set("workingDir", workDir)
 	v.Set("disableKinds", []string{"taxonomy", "term", "page"})
-	b := newTestSitesBuilder(t).WithLogger(loggers.NewWarningLogger())
+	b := newTestSitesBuilder(t).WithLogger(logger)
 
 	// Need to use OS fs for this.
 	b.Fs = hugofs.NewDefault(v)
@@ -108,12 +114,10 @@ Transpiled: {{ $transpiled.Content | safeJS }}
 	_, err = exec.Command("npm", "install").CombinedOutput()
 	b.Assert(err, qt.IsNil)
 
-	out, err := captureStderr(func() error {
-		return b.BuildE(BuildCfg{})
+	b.Build(BuildCfg{})
 
-	})
 	// Make sure Node sees this.
-	b.Assert(out, qt.Contains, "Hugo Environment: production")
+	b.Assert(logBuf.String(), qt.Contains, "babel: Hugo Environment: production")
 	b.Assert(err, qt.IsNil)
 
 	b.AssertFileContent("public/index.html", `

hugolib/resource_chain_test.go

@@ -14,10 +14,15 @@
 package hugolib
 
 import (
+	"bytes"
+
+	jww "github.com/spf13/jwalterweatherman"
+
 	"fmt"
 	"io"
 	"math/rand"
 	"os"
+
 	"os/exec"
 	"path/filepath"
 	"runtime"
@@ -893,10 +898,13 @@ h1 {
 	c.Assert(err, qt.IsNil)
 	defer clean()
 
+	var logBuf bytes.Buffer
+
 	newTestBuilder := func(v *viper.Viper) *sitesBuilder {
 		v.Set("workingDir", workDir)
 		v.Set("disableKinds", []string{"taxonomy", "term", "page"})
-		b := newTestSitesBuilder(t).WithLogger(loggers.NewWarningLogger())
+		logger := loggers.NewBasicLoggerForWriter(jww.LevelInfo, &logBuf)
+		b := newTestSitesBuilder(t).WithLogger(logger)
 		// Need to use OS fs for this.
 		b.Fs = hugofs.NewDefault(v)
 		b.WithWorkingDir(workDir)
@@ -942,14 +950,10 @@ class-in-b {
 	b.Assert(os.Chdir(workDir), qt.IsNil)
 	_, err = exec.Command("npm", "install").CombinedOutput()
 	b.Assert(err, qt.IsNil)
-
-	out, _ := captureStderr(func() error {
 	b.Build(BuildCfg{})
-		return nil
-	})
 
 	// Make sure Node sees this.
-	b.Assert(out, qt.Contains, "Hugo Environment: production")
+	b.Assert(logBuf.String(), qt.Contains, "Hugo Environment: production")
 
 	b.AssertFileContent("public/index.html", `
 Styles RelPermalink: /css/styles.css

modules/client.go

@@ -531,8 +531,6 @@ func (c *Client) runGo(
 		return nil
 	}
 
-	//defer c.logger.PrintTimer(time.Now(), fmt.Sprint(args))
-
 	stderr := new(bytes.Buffer)
 	cmd := exec.CommandContext(ctx, "go", args...)
 

resources/resource_transformers/babel/babel.go

@@ -15,11 +15,12 @@ package babel
 
 import (
 	"io"
-	"os"
 	"os/exec"
 	"path/filepath"
 	"strconv"
 
+	"github.com/gohugoio/hugo/common/loggers"
+
 	"github.com/gohugoio/hugo/common/hugo"
 	"github.com/gohugoio/hugo/resources/internal"
 
@@ -157,7 +158,7 @@ func (t *babelTransformation) Transform(ctx *resources.ResourceTransformationCtx
 	cmd := exec.Command(binary, cmdArgs...)
 
 	cmd.Stdout = ctx.To
-	cmd.Stderr = os.Stderr
+	cmd.Stderr = loggers.LoggerToWriterWithPrefix(logger.INFO, "babel")
 	cmd.Env = hugo.GetExecEnviron(t.rs.Cfg)
 
 	stdin, err := cmd.StdinPipe()

resources/resource_transformers/postcss/postcss.go

@@ -36,7 +36,6 @@ import (
 	"github.com/gohugoio/hugo/hugofs"
 	"github.com/pkg/errors"
 
-	"os"
 	"os/exec"
 
 	"github.com/mitchellh/mapstructure"
@@ -199,9 +198,10 @@ func (t *postcssTransformation) Transform(ctx *resources.ResourceTransformationC
 	cmd := exec.Command(binary, cmdArgs...)
 
 	var errBuf bytes.Buffer
+	infoW := loggers.LoggerToWriterWithPrefix(logger.INFO, "postcss")
 
 	cmd.Stdout = ctx.To
-	cmd.Stderr = io.MultiWriter(os.Stderr, &errBuf)
+	cmd.Stderr = io.MultiWriter(infoW, &errBuf)
 	cmd.Env = hugo.GetExecEnviron(t.rs.Cfg)
 
 	stdin, err := cmd.StdinPipe()