test(cli): add tests for the CLI

tests/integration/cli/test_cli.py

@@ -0,0 +1,34 @@
+# Copyright 2026 jCloud
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import subprocess
+import sys
+
+def test_cli():
+    result = subprocess.run(
+        [
+            sys.executable,
+            '-m',
+            'jcloud_docsgen',
+            '--help'
+        ],
+        capture_output = True,
+        text = True
+    )
+    stdout = result.stdout.lower()
+    assert \
+        'usage:' in stdout and \
+        'positional arguments' in stdout and \
+        'options' in stdout and \
+        '--help' in stdout

tests/unit/cli/python_project/expected/pkg/module.md

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+# Module `pkg.module`
+
+## Function `f`
+
+Does something.
+
+
+### Parameters
+
+| Parameter | Type | Kind | Default value | Description |
+| --- | --- | --- | --- | --- |
+| `a` | `int` | normal | `42` | A parameter. |
+
+<details><summary><h3 style="display:inline">Docstring</h3></summary>Does something.
+
+:param a: A parameter.
+:type a: int
+
+:return: A string.
+:rtype: str</details>

tests/unit/cli/python_project/project/src/pkg/module.py

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+def f(a: int = 42) -> str:
+    '''
+    Does something.
+
+    :param a: A parameter.
+    :type a: int
+
+    :return: A string.
+    :rtype: str
+    '''
+    ...

tests/unit/cli/test_parser.py

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+# Copyright 2026 jCloud
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pytest
+from jcloud_docsgen.cli.cli import create_argument_parser
+
+@pytest.mark.parametrize('lang', [
+    'javascript',
+    'Python',
+    'PYTHON'
+])
+def test_language_error(lang):
+    parser = create_argument_parser()
+
+    with pytest.raises(SystemExit):
+        parser.parse_args([lang])
+
+@pytest.mark.parametrize('lang', [
+    'python'
+])
+def test_language_success(lang):
+    parser = create_argument_parser()
+    parser.parse_args([lang])

tests/unit/cli/test_python.py

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+# Copyright 2026 jCloud
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pathlib
+import pytest
+from jcloud_docsgen.cli.cli import create_argument_parser, main as cli_main
+
+def test_sections_error():
+    parser = create_argument_parser()
+
+    with pytest.raises(SystemExit):
+        parser.parse_args([
+            'python',
+            '-s',
+            'param' # correct: `params`
+        ])
+
+    with pytest.raises(SystemExit):
+        parser.parse_args([
+            'python',
+            '-s',
+            'params',
+            'docstrng' # correct: `docstring`
+        ])
+
+def test_sections_success():
+    parser = create_argument_parser()
+
+    parser.parse_args([
+        'python',
+        '-s',
+        'params'
+    ])
+    parser.parse_args([
+        'python',
+        '-s',
+        'params',
+        'docstring'
+    ])
+
+def test_docs_generation(expectdir):
+    with expectdir('python_project') as output_dir:
+        output_dir: pathlib.Path
+        input_dir = pathlib.Path(__file__).parent / 'python_project/project'
+        cli_main([
+            'python',
+            '-s',
+            'params',
+            'docstring',
+            '-HTo',
+            str(output_dir),
+            str(input_dir)
+        ])