test: Add test for export-roles --indent's argument “duck casting” to int

flask_appbuilder/cli.py

@@ -28,6 +28,21 @@ def echo_header(title):
     click.echo(click.style("-" * len(title), fg="green"))
 
 
+def cast_int_like_to_int(cli_arg: Union[None, str, int]) -> Union[None, str, int]:
+    """Cast int-like objects to int if possible
+
+    If the arg cannot be cast to an integer, return the unmodified object instead."""
+    try:
+        cli_arg_int = int(cli_arg)
+        return cli_arg_int
+    except TypeError:
+        # Don't cast if None
+        return cli_arg
+    except ValueError:
+        # Don't cast non-int-like strings
+        return cli_arg
+
+
 @click.group()
 def fab():
     """ FAB flask group commands"""
@@ -155,17 +170,9 @@ def export_roles(
     path: Optional[str] = None, indent: Optional[Union[int, str]] = None
 ) -> None:
     """Exports roles with permissions and view menus to JSON file"""
-    # Cast negative numbers to int (as they're passed as str from CLI)
-    try:
-        indent = int(indent)
-    except TypeError:
-        # Don't cast None
-        pass
-    except ValueError:
-        # Don't cast non-int-like strings
-        pass
-
-    current_app.appbuilder.sm.export_roles(path=path, indent=indent)
+    # Cast negative numbers to int (as they are passed as str from CLI)
+    cast_indent = cast_int_like_to_int(indent)
+    current_app.appbuilder.sm.export_roles(path=path, indent=cast_indent)
 
 
 @fab.command("import-roles")

flask_appbuilder/tests/test_fab_cli.py

@@ -9,6 +9,7 @@
 from flask import Flask
 from flask_appbuilder import AppBuilder, SQLA
 from flask_appbuilder.cli import (
+    cast_int_like_to_int,
     create_app,
     create_permissions,
     create_user,
@@ -79,6 +80,22 @@ def test_list_views(self):
             self.assertIn("List of registered views", result.output)
             self.assertIn(" Route:/api/v1/security", result.output)
 
+    def test_cast_int_like_to_int(self):
+        scenarii = {
+            -1: -1,
+            0: 0,
+            1: 1,
+            "-1": -1,
+            "0": 0,
+            "1": 1,
+            "+1": 1,
+            "foo": "foo",
+            None: None,
+        }
+
+        for input, expected_output in scenarii.items():
+            self.assertEqual(cast_int_like_to_int(input), expected_output)
+
 
 class SQLAlchemyImportExportTestCase(FABTestCase):
     def setUp(self):