refactor test_return_codes

... so works in a similar way as test_exit_codes.

src/borg/testsuite/archiver/return_codes_test.py

@@ -3,28 +3,28 @@ import os
 from ...constants import *  # NOQA
 from ...helpers import IncludePatternNeverMatchedWarning
 from ...repository import Repository
-from . import cmd, cmd_fixture, changedir, generate_archiver_tests  # NOQA
+from . import cmd, changedir, generate_archiver_tests  # NOQA
 
 pytest_generate_tests = lambda metafunc: generate_archiver_tests(metafunc, kinds="local,remote,binary")  # NOQA
 
 
-def test_return_codes(cmd_fixture, tmpdir):
-    repo = tmpdir / "repo"  # borg creates the directory
-    input = tmpdir.mkdir("input")
-    output = tmpdir.mkdir("output")
-    input.join("test_file").write("content")
-    rc, out = cmd_fixture("--repo=%s" % str(repo), "repo-create", "--encryption=none")
-    assert rc == EXIT_SUCCESS
-    rc, out = cmd_fixture("--repo=%s" % repo, "create", "archive", str(input))
-    assert rc == EXIT_SUCCESS
-    with changedir(str(output)):
-        rc, out = cmd_fixture("--repo=%s" % repo, "extract", "archive")
-        assert rc == EXIT_SUCCESS
-    rc, out = cmd_fixture("--repo=%s" % repo, "extract", "archive", "does/not/match")
-    assert rc == IncludePatternNeverMatchedWarning().exit_code
+def test_return_codes(archivers, request):
+    archiver = request.getfixturevalue(archivers)
+    cmd(archiver, "repo-create", "--encryption=none")
+    cmd(archiver, "create", "archive", "input")
+    with changedir("output"):
+        cmd(archiver, "extract", "archive")
+    cmd(
+        archiver,
+        "extract",
+        "archive",
+        "does/not/match",
+        fork=True,
+        exit_code=IncludePatternNeverMatchedWarning().exit_code,
+    )
 
 
-def test_exit_codes(archivers, request, tmpdir, monkeypatch):
+def test_exit_codes(archivers, request, monkeypatch):
     archiver = request.getfixturevalue(archivers)
     # we create the repo path, but do NOT initialize the borg repo,
     # so the borg create commands are expected to fail with DoesNotExist (was: InvalidRepository in borg 1.4).