Fixed #1356: return status when arguments are passed in without files…

… or a content stream.

CHANGELOG.md

@@ -3,6 +3,9 @@ Changelog
 
 NOTE: isort follows the [semver](https://semver.org/) versioning standard.
 
+### 5.2.2 July 30, 2020
+  - Fixed #1356: return status when arguments are passed in without files or a content stream.
+
 ### 5.2.1 July 28, 2020
   - Update precommit to default to filtering files that are defined in skip.
   - Improved relative path detection for `skip` config usage.

isort/main.py

@@ -739,7 +739,10 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
     file_names = arguments.pop("files", [])
     if not file_names and not show_config:
         print(QUICK_GUIDE)
-        return
+        if arguments:
+            sys.exit(f"Error: arguments passed in without any paths or content.")
+        else:
+            return
     elif file_names == ["-"] and not show_config:
         arguments.setdefault("settings_path", os.getcwd())
         api.sort_stream(

tests/test_main.py

@@ -99,12 +99,18 @@ def test_main(capsys, tmpdir):
     ]
     tmpdir.mkdir(".git")
 
-    # If no files are passed in the quick guide is returned
-    main.main(base_args)
+    # If nothing is passed in the quick guide is returned without erroring
+    main.main([])
     out, error = capsys.readouterr()
     assert main.QUICK_GUIDE in out
     assert not error
 
+    # If no files are passed in but arguments are the quick guide is returned, alongside an error.
+    with pytest.raises(SystemExit):
+        main.main(base_args)
+    out, error = capsys.readouterr()
+    assert main.QUICK_GUIDE in out
+
     # Unless the config is requested, in which case it will be returned alone as JSON
     main.main(base_args + ["--show-config"])
     out, error = capsys.readouterr()