Added test for main function, template and json for running test

tests/main.py

@@ -0,0 +1,21 @@
+from docxtpl.__main__ import main
+import sys
+from pathlib import Path
+
+TEMPLATE_PATH = 'templates/template_for_main_test.docx'
+JSON_PATH = 'templates/json_for_main_test.json'
+OUTPUT_FILENAME = 'output/output_for_main_test.docx'
+OVERWRITE = '-o'
+
+
+# Simulate command line arguments, running with overwrite flag so test can be
+# run repeatedly without need for confirmation:
+sys.argv[1:] = [TEMPLATE_PATH, JSON_PATH, OUTPUT_FILENAME, OVERWRITE]
+
+main()
+
+output_path = Path(OUTPUT_FILENAME)
+
+if output_path.exists():
+    print(f'File {output_path.resolve()} exists.')
+

tests/templates/json_for_main_test.json

@@ -0,0 +1,8 @@
+{"json_dict_var" : {"json_dict_var":"successfully inserted"},
+"json_array_var": ["json","array","var","successfully", "inserted"],
+"json_string_var":"json_string_var successfully inserted",
+"json_int_var":123,
+"json_float_var":1.234,
+"json_true_var":true,
+"json_false_var":false,
+"json_none_var":null}