Enhance: Add dummy function w/ parametrized tests (#161)

* fix #35
* Enhance: Add dummy function w/ parametrized tests
* Update CHANGELOG

Author: ojeda-e

CHANGELOG.md

@@ -31,6 +31,7 @@ The rules for this file:
 
 ### Added
 <!-- New added features -->
+- Add example of API import with unit tests using pytest parametrize (PR #161)
 - Extend license options to MIT (default), GPLv3+, BSD 3-clause and Apache 2 (PR #156)
 - Add black configurartion to `pyproject.toml` (Issue #73, PR #75)
 - Cookiecutter version dependency (Issue #33, PR #46)

{{cookiecutter.repo_name}}/{{cookiecutter.package_name}}/example_api.py

@@ -0,0 +1,3 @@
+def example_function(number: float) -> float:
+    """Return `2*number`. This is and example for tests."""
+    return 2 * number

{{cookiecutter.repo_name}}/{{cookiecutter.package_name}}/tests/test_{{cookiecutter.package_name}}.py

@@ -6,6 +6,7 @@
 import sys
 import pytest
 import {{cookiecutter.package_name}}
+from {{cookiecutter.package_name}}.example_api import example_function
 
 
 def test_{{cookiecutter.package_name}}_imported():
@@ -17,3 +18,16 @@ def test_mdanalysis_logo_length(mdanalysis_logo_text):
     """Example test using a fixture defined in conftest.py"""
     logo_lines = mdanalysis_logo_text.split("\n")
     assert len(logo_lines) == 46, "Logo file does not have 46 lines!"
+
+@pytest.mark.parametrize(
+    "value, expected",
+    [
+        (0, 0),
+        (1, 2),
+        (-5, -10),
+        (1.5, 3.0),
+        (-2.0, -4.0)
+    ],
+)
+def test_double_value(value, expected):
+    assert example_function(value) == expected