Show --check-status warning with --quiet as well. (#1026)

Fixes #1028

CHANGELOG.rst

@@ -9,7 +9,7 @@ This project adheres to `Semantic Versioning <https://semver.org/>`_.
 
 `2.4.0-dev`_ (unreleased)
 -------------------------
-
+* Show a ``--check-status`` warning with ``--quiet`` as well, not only when the output si redirected. (`#1026`_)
 * Fixed upload with ``--session`` (`#1020`_).
 * Fixed a missing blank line between request and response (`#1006`_).
 
@@ -488,3 +488,4 @@ This project adheres to `Semantic Versioning <https://semver.org/>`_.
 .. _#963: https://github.com/httpie/httpie/issues/963
 .. _#1006: https://github.com/httpie/httpie/issues/1006
 .. _#1020: https://github.com/httpie/httpie/issues/1020
+.. _#1026: https://github.com/httpie/httpie/issues/1026

README.rst

@@ -1292,7 +1292,7 @@ Quiet output
 ------------
 
 ``--quiet`` redirects all output that would otherwise go to ``stdout``
-and ``stderr``  (except for error messages) to ``/dev/null``.
+and ``stderr`` to ``/dev/null`` (except for errors and warnings).
 This doesn’t affect output to a file via ``--output`` or ``--download``.
 
 .. code-block:: bash

httpie/core.py

@@ -185,7 +185,7 @@ def request_body_read_callback(chunk: bytes):
                 final_response = message
                 if args.check_status or downloader:
                     exit_status = http_status_to_exit_status(http_status=message.status_code, follow=args.follow)
-                    if not env.stdout_isatty and exit_status != ExitStatus.SUCCESS:
+                    if exit_status != ExitStatus.SUCCESS and (not env.stdout_isatty or args.quiet):
                         env.log_error(f'HTTP {message.raw.status} {message.raw.reason}', level='warning')
             write_message(requests_message=message, env=env, args=args, with_headers=with_headers,
                           with_body=do_write_body)

tests/test_output.py

@@ -54,6 +54,21 @@ def test_quiet(self, httpbin, argument_name):
         assert r == ''
         assert r.stderr == ''
 
+    def test_quiet_with_check_status_non_zero(self, httpbin):
+        r = http(
+            '--quiet', '--check-status', httpbin + '/status/500',
+            tolerate_error_exit_status=True,
+        )
+        assert 'http: warning: HTTP 500' in r.stderr
+
+    def test_quiet_with_check_status_non_zero_pipe(self, httpbin):
+        r = http(
+            '--quiet', '--check-status', httpbin + '/status/500',
+            tolerate_error_exit_status=True,
+            env=MockEnvironment(stdout_isatty=False)
+        )
+        assert 'http: warning: HTTP 500' in r.stderr
+
     @mock.patch('httpie.cli.argtypes.AuthCredentials._getpass',
                 new=lambda self, prompt: 'password')
     def test_quiet_with_password_prompt(self, httpbin):