test that explicit bool works for tapify

Author: martinjm97

src/tap/tapify.py

@@ -300,6 +300,7 @@ def tapify(
     known_only: bool = False,
     command_line_args: Optional[list[str]] = None,
     explicit_bool: bool = False,
+    underscores_to_dashes: bool = False,
     description: Optional[str] = None,
     **func_kwargs,
 ) -> OutputType:
@@ -312,6 +313,7 @@ def tapify(
     :param explicit_bool: Booleans can be specified on the command line as `--arg True` or `--arg False` rather than
                           `--arg`. Additionally, booleans can be specified by prefixes of True and False with any
                           capitalization as well as 1 or 0.
+    :param underscores_to_dashes: If True, convert underscores in flag names to dashes.
     :param description: The description displayed in the help message—the same description passed in
                         `argparse.ArgumentParser(description=...)`. By default, it's extracted from `class_or_function`'s
                         docstring.
@@ -327,7 +329,7 @@ def tapify(
     # Create a Tap object
     if description is None:
         description = "\n".join(filter(None, (docstring.short_description, docstring.long_description)))
-    tap = tap_class(description=description, explicit_bool=explicit_bool)
+    tap = tap_class(description=description, explicit_bool=explicit_bool, underscores_to_dashes=underscores_to_dashes)
 
     # If any func_kwargs remain, they are not used in the function, so raise an error
     known_only = known_only or tap_data.known_only

tests/test_tapify.py

@@ -1521,5 +1521,41 @@ def test_tapify_has_kwargs_replace_default(self) -> None:
             self.assertEqual(output, "1_5_c=3-d=4")
 
 
+class TestTapifyUnderscoresToDashes(unittest.TestCase):
+    def setUp(self) -> None:
+        class MyClass:
+            def __init__(self, my_arg: str):
+                self.my_arg = my_arg
+
+            def __eq__(self, other: str) -> bool:
+                return self.my_arg == other
+
+        @dataclass
+        class DataClassTarget:
+            my_arg: str
+
+            def __eq__(self, other: str) -> bool:
+                return self.my_arg == other
+
+        def my_function(my_arg: str) -> str:
+            return my_arg
+
+        self.class_or_functions = [my_function, MyClass, DataClassTarget]
+
+    def test_underscores_to_dashes(self) -> None:
+        for target in self.class_or_functions:
+            # With underscores_to_dashes True and using dashes in the args.
+            instance = tapify(target, command_line_args=["--my-arg", "value"], underscores_to_dashes=True)
+            self.assertEqual(instance, "value")
+
+            # With underscores_to_dashes False and using underscore in the args.
+            instance = tapify(target, command_line_args=["--my_arg", "value"], underscores_to_dashes=False)
+            self.assertEqual(instance, "value")
+
+            # Using underscore when dashes are expected causes a parse error.
+            with self.assertRaises(SystemExit):
+                tapify(target, command_line_args=["--my_arg", "value"], underscores_to_dashes=True)
+
+
 if __name__ == "__main__":
     unittest.main()