From 863bfc44d2456cfc163d6ff3db4100435258c874 Mon Sep 17 00:00:00 2001
From: Daniel Bevenius <daniel.bevenius@gmail.com>
Date: Thu, 17 Dec 2020 05:06:20 +0100
Subject: [PATCH] test: redirect stderr EnvironmentWithNoESMLoader

This commit adds a suggestion to redirect stderr for
EnvironmentTest.EnvironmentWithNoESMLoader.

The motivation for this is that currently this tests prints the
following error (which is expected):

vm:module(0):1
globalThis.importResult = import("")
^

Error: Not supported
 at vm:module(0):1:1
 at SourceTextModule.evaluate (node:internal/vm/module:229:23)
 at node:embedder_main_12:1:328
 at processTicksAndRejections (node:internal/process/task_queues:93:5)

It might not be obvious which test caused this error just by looking at
the output above and it would be nice if it was not displayed.

PR-URL: https://github.com/nodejs/node/pull/36548
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
---
 test/cctest/test_environment.cc | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/test/cctest/test_environment.cc b/test/cctest/test_environment.cc
index a2066121cd964f..862dfd5780868a 100644
--- a/test/cctest/test_environment.cc
+++ b/test/cctest/test_environment.cc
@@ -5,6 +5,8 @@
 #include <string>
 #include "gtest/gtest.h"
 #include "node_test_fixture.h"
+#include <stdio.h>
+#include <cstdio>
 
 using node::AtExit;
 using node::RunAtExit;
@@ -66,7 +68,34 @@ TEST_F(EnvironmentTest, EnvironmentWithESMLoader) {
       "})()");
 }
 
+class RedirectStdErr {
+ public:
+  explicit RedirectStdErr(const char* filename) : filename_(filename) {
+    fflush(stderr);
+    fgetpos(stderr, &pos_);
+    fd_ = dup(fileno(stderr));
+    freopen(filename_, "w", stderr);
+  }
+
+  ~RedirectStdErr() {
+    fflush(stderr);
+    dup2(fd_, fileno(stderr));
+    close(fd_);
+    remove(filename_);
+    clearerr(stderr);
+    fsetpos(stderr, &pos_);
+  }
+
+ private:
+  int fd_;
+  fpos_t pos_;
+  const char* filename_;
+};
+
 TEST_F(EnvironmentTest, EnvironmentWithNoESMLoader) {
+  // The following line will cause stderr to get redirected to avoid the
+  // error that would otherwise be printed to the console by this test.
+  RedirectStdErr redirect_scope("environment_test.log");
   const v8::HandleScope handle_scope(isolate_);
   Argv argv;
   Env env {handle_scope, argv, node::EnvironmentFlags::kNoRegisterESMLoader};