net/http: direct server logs to test output in tests

Set a logger in newClientServerTest that directs the server
log output to the testing.T's log, so log output gets properly
associated with the test that caused it.

Change-Id: I13686ca35c3e21adae16b2fc37ce36daea3df9d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/452075
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/net/http/clientserver_test.go b/src/net/http/clientserver_test.go
index 87e34cef85..da5671d9b9 100644
--- a/src/net/http/clientserver_test.go
+++ b/src/net/http/clientserver_test.go
@@ -170,6 +170,10 @@ func newClientServerTest(t testing.TB, mode testMode, h Handler, opts ...any) *c
 		}
 	}
 
+	if cst.ts.Config.ErrorLog == nil {
+		cst.ts.Config.ErrorLog = log.New(testLogWriter{t}, "", 0)
+	}
+
 	switch mode {
 	case http1Mode:
 		cst.ts.Start()
@@ -198,6 +202,15 @@ func newClientServerTest(t testing.TB, mode testMode, h Handler, opts ...any) *c
 	return cst
 }
 
+type testLogWriter struct {
+	t testing.TB
+}
+
+func (w testLogWriter) Write(b []byte) (int, error) {
+	w.t.Logf("server log: %v", strings.TrimSpace(string(b)))
+	return len(b), nil
+}
+
 // Testing the newClientServerTest helper itself.
 func TestNewClientServerTest(t *testing.T) {
 	run(t, testNewClientServerTest, []testMode{http1Mode, https1Mode, http2Mode})