log/slog: restore the original log setting before test exits

Change-Id: Ib3daffb8a4cc018d62ed6e5741355b1c1a206034
Reviewed-on: https://go-review.googlesource.com/c/go/+/515775
Run-TryBot: Andy Pan <panjf2000@gmail.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>

diff --git a/src/log/slog/logger_test.go b/src/log/slog/logger_test.go
index 559b9d66b4567c74b8c299ccddd9c19c9f578edd..7d0243e415df6081fc57bceac6e4ec770d22dd7a 100644 (file)
--- a/src/log/slog/logger_test.go
+++ b/src/log/slog/logger_test.go
@@ -12,7 +12,6 @@ import (
        "io"
        "log"
        loginternal "log/internal"
-       "os"
        "path/filepath"
        "regexp"
        "runtime"
@@ -73,9 +72,13 @@ func TestConnections(t *testing.T) {
        // tests might change the default logger using SetDefault. Also ensure we
        // restore the default logger at the end of the test.
        currentLogger := Default()
+       currentLogWriter := log.Writer()
+       currentLogFlags := log.Flags()
        SetDefault(New(newDefaultHandler(loginternal.DefaultOutput)))
        t.Cleanup(func() {
                SetDefault(currentLogger)
+               log.SetOutput(currentLogWriter)
+               log.SetFlags(currentLogFlags)
        })
 
        // The default slog.Logger's handler uses the log package's default output.
@@ -598,10 +601,12 @@ func TestPanics(t *testing.T) {
        // tests might change the default logger using SetDefault. Also ensure we
        // restore the default logger at the end of the test.
        currentLogger := Default()
+       currentLogWriter := log.Writer()
+       currentLogFlags := log.Flags()
        t.Cleanup(func() {
                SetDefault(currentLogger)
-               log.SetOutput(os.Stderr)
-               log.SetFlags(log.LstdFlags)
+               log.SetOutput(currentLogWriter)
+               log.SetFlags(currentLogFlags)
        })
 
        var logBuf bytes.Buffer