Merge pull request #2603 from johannaengland/bugfix/nav-command-no-ar…

…guments

Show help text when running nav command without arguments

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 This changelog format was introduced in NAV 5.4.0. Older changelogs can be
 found in the [HISTORY](HISTORY) file.
 
+## Unreleased
+
+### Fixed
+
+#### User-visible fixes
+- Show help text when running nav command without arguments instead of error ([#2601](https://github.com/Uninett/nav/issues/2601), [#2603](https://github.com/Uninett/nav/pull/2603))
+
 ## [5.6.1] - 2023-03-23
 
 ### Fixed

bin/nav

@@ -47,8 +47,13 @@ except (OSError, CrontabError) as _error:
 
 def main(args):
     """Main execution point"""
-    args = make_argparser().parse_args()
-    args.func(args)
+    parser = make_argparser()
+    args = parser.parse_args()
+    try:
+        args.func(args)
+    except AttributeError:
+        parser.print_help(sys.stderr)
+        sys.exit(0)
 
 
 def make_argparser():

tests/integration/bin_test.py

@@ -36,3 +36,25 @@ def test_naventity_runs_without_error_with_arguments(localhost, snmpsim):
         print(fail.decode('utf-8'))
 
     assert retcode == 0
+
+
+def test_nav_runs_without_error_without_arguments():
+    """
+    Verifies that nav runs with a zero exit code when given no arguments
+
+    Added in regards to: https://github.com/Uninett/nav/issues/2601
+    """
+    proc = subprocess.Popen(
+        ["./bin/nav"],
+        stderr=subprocess.STDOUT,
+        stdout=subprocess.PIPE,
+    )
+    (done, fail) = proc.communicate()
+    retcode = proc.wait()
+
+    if done:
+        print(done.decode('utf-8'))
+    if fail:
+        print(fail.decode('utf-8'))
+
+    assert retcode == 0