test: logStream() behaves correctly like a good kiddo

Co-authored-by: Roberto Abdelkader Martínez Pérez <robertomartinezp@gmail.com>

internal/server/user/mux/handlerbuilder.go

@@ -20,6 +20,7 @@ import (
 	"bufio"
 	"log"
 	"net/http"
+	"io"
 	"os"
 
 	"github.com/google/uuid"
@@ -31,6 +32,7 @@ import (
 
 var spawner = spawn.Spawn
 var idGenerator = uuid.NewUUID
+var logHandler io.Writer = os.Stdout
 
 func handlerBuilder(route model.Route) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -77,7 +79,7 @@ func handlerBuilder(route model.Route) http.Handler {
 
 func logStream(handlerId string, streamName string, stream *os.File) {
 	defer stream.Close()
-	execLog := log.New(os.Stdout, "", log.Ldate|log.Ltime|log.LUTC|log.Lmicroseconds)
+	execLog := log.New(logHandler, "", log.Ldate|log.Ltime|log.LUTC|log.Lmicroseconds)
 	scanner := bufio.NewScanner(stream)
 	for scanner.Scan() {
 		execLog.Printf("%s %s: %s", handlerId, streamName, scanner.Text())