Implement Close() for zerolog.FilteredLevelWriter (#715)

console_test.go

@@ -2,9 +2,11 @@ package zerolog_test
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 	"time"
@@ -315,16 +317,33 @@ func TestConsoleWriter(t *testing.T) {
 
 		ts := time.Unix(0, 0)
 		d := ts.UTC().Format(time.RFC3339)
-		evt := `{"time": "` + d + `", "level": "debug", "message": "Foobar", "foo": "bar", "caller": "` + cwd + `/foo/bar.go"}`
-		// t.Log(evt)
 
-		_, err = w.Write([]byte(evt))
+		fields := map[string]interface{}{
+			"time":    d,
+			"level":   "debug",
+			"message": "Foobar",
+			"foo":     "bar",
+			"caller":  filepath.Join(cwd, "foo", "bar.go"),
+		}
+
+		evt, err := json.Marshal(fields)
+		if err != nil {
+			t.Fatalf("Cannot marshal fields: %s", err)
+		}
+
+		_, err = w.Write(evt)
 		if err != nil {
 			t.Errorf("Unexpected error when writing output: %s", err)
 		}
 
+		// Define the expected output with forward slashes
 		expectedOutput := ts.Format(time.Kitchen) + " DBG foo/bar.go > Foobar foo=bar\n"
+
+		// Get the actual output and normalize path separators to forward slashes
 		actualOutput := buf.String()
+		actualOutput = strings.ReplaceAll(actualOutput, string(os.PathSeparator), "/")
+
+		// Compare the normalized actual output to the expected output
 		if actualOutput != expectedOutput {
 			t.Errorf("Unexpected output %q, want: %q", actualOutput, expectedOutput)
 		}
@@ -451,7 +470,7 @@ func TestConsoleWriterConfiguration(t *testing.T) {
 	})
 
 	t.Run("Sets TimeFormat and TimeLocation", func(t *testing.T) {
-		locs := []*time.Location{ time.Local, time.UTC }
+		locs := []*time.Location{time.Local, time.UTC}
 
 		for _, location := range locs {
 			buf := &bytes.Buffer{}

diode/diode_test.go

@@ -76,6 +76,58 @@ func TestFatal(t *testing.T) {
 	}
 }
 
+type SlowWriter struct{}
+
+func (rw *SlowWriter) Write(p []byte) (n int, err error) {
+	time.Sleep(200 * time.Millisecond)
+	fmt.Print(string(p))
+	return len(p), nil
+}
+
+func TestFatalWithFilteredLevelWriter(t *testing.T) {
+	if os.Getenv("TEST_FATAL_SLOW") == "1" {
+		slowWriter := SlowWriter{}
+		diodeWriter := diode.NewWriter(&slowWriter, 500, 0, func(missed int) {
+			fmt.Printf("Missed %d logs\n", missed)
+		})
+		leveledDiodeWriter := zerolog.LevelWriterAdapter{
+			Writer: &diodeWriter,
+		}
+		filteredDiodeWriter := zerolog.FilteredLevelWriter{
+			Writer: &leveledDiodeWriter,
+			Level:  zerolog.InfoLevel,
+		}
+		logger := zerolog.New(&filteredDiodeWriter)
+		logger.Fatal().Msg("test")
+		return
+	}
+
+	cmd := exec.Command(os.Args[0], "-test.run=TestFatalWithFilteredLevelWriter")
+	cmd.Env = append(os.Environ(), "TEST_FATAL_SLOW=1")
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = cmd.Start()
+	if err != nil {
+		t.Fatal(err)
+	}
+	slurp, err := io.ReadAll(stdout)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = cmd.Wait()
+	if err == nil {
+		t.Error("Expected log.Fatal to exit with non-zero status")
+	}
+
+	got := cbor.DecodeIfBinaryToString(slurp)
+	want := "{\"level\":\"fatal\",\"message\":\"test\"}\n"
+	if got != want {
+		t.Errorf("Expected output %q, got: %q", want, got)
+	}
+}
+
 func Benchmark(b *testing.B) {
 	log.SetOutput(io.Discard)
 	defer log.SetOutput(os.Stderr)

writer.go

@@ -213,6 +213,15 @@ func (w *FilteredLevelWriter) WriteLevel(level Level, p []byte) (int, error) {
 	return len(p), nil
 }
 
+// Call the underlying writer's Close method if it is an io.Closer. Otherwise
+// does nothing.
+func (w *FilteredLevelWriter) Close() error {
+	if closer, ok := w.Writer.(io.Closer); ok {
+		return closer.Close()
+	}
+	return nil
+}
+
 var triggerWriterPool = &sync.Pool{
 	New: func() interface{} {
 		return bytes.NewBuffer(make([]byte, 0, 1024))