Implement production-dotenv-files-to-dotenv-file merge script

{{cookiecutter.project_slug}}/merge_production_dotenvs_in_dotenv.py

@@ -0,0 +1,65 @@
+import os
+import pytest
+
+PROJECT_DIR_PATH = os.path.dirname(os.path.realpath(__file__))
+PRODUCTION_DOTENV_DIR_PATH = os.path.join(PROJECT_DIR_PATH, '.envs', '.production')
+PRODUCTION_DOTENV_FILE_PATHS = [
+    os.path.join(PRODUCTION_DOTENV_DIR_PATH, '.django'),
+    os.path.join(PRODUCTION_DOTENV_DIR_PATH, '.postgres'),
+    os.path.join(PRODUCTION_DOTENV_DIR_PATH, '.caddy'),
+]
+DOTENV_FILE_PATH = os.path.join(PROJECT_DIR_PATH, '.env')
+
+
+def merge(output_file_path, merged_file_paths, append_linesep=True):
+    with open(output_file_path, 'w+') as output_file:
+        for merged_file_path in merged_file_paths:
+            with open(merged_file_path, 'r') as merged_file:
+                merged_file_content = merged_file.read()
+                output_file.write(merged_file_content)
+                if append_linesep:
+                    output_file.write(os.linesep)
+
+
+def main():
+    merge(DOTENV_FILE_PATH, PRODUCTION_DOTENV_FILE_PATHS)
+
+
+@pytest.mark.parametrize('merged_file_count', range(3))
+@pytest.mark.parametrize('append_linesep', [True, False])
+def test_when_merging_given_valid_arguments_should_succeed(tmpdir_factory,
+                                                           merged_file_count,
+                                                           append_linesep):
+    tmp_dir_path = str(tmpdir_factory.getbasetemp())
+
+    output_file_path = os.path.join(tmp_dir_path, '.env')
+
+    expected_output_file_content = ''
+    merged_file_paths = []
+    for i in range(merged_file_count):
+        merged_file_ord = i + 1
+
+        merged_filename = '.service{}'.format(merged_file_ord)
+        merged_file_path = os.path.join(tmp_dir_path, merged_filename)
+
+        merged_file_content = merged_filename * merged_file_ord
+
+        with open(merged_file_path, 'w+') as file:
+            file.write(merged_file_content)
+
+        expected_output_file_content += merged_file_content
+        if append_linesep:
+            expected_output_file_content += os.linesep
+
+        merged_file_paths.append(merged_file_path)
+
+    merge(output_file_path, merged_file_paths, append_linesep)
+
+    with open(output_file_path, 'r') as output_file:
+        actual_output_file_content = output_file.read()
+
+    assert actual_output_file_content == expected_output_file_content
+
+
+if __name__ == '__main__':
+    main()