Add --dry option

Author: albertas

README.md

@@ -31,6 +31,7 @@ ignore-names-in-files = ["migrations"]
 | Option                                    | Type | Meaning  |
 |-------------------------------------------|------|----------------------------------------------------------------------|
 |`--fix`                                    | -    | Automatically remove detected unused code expressions from the code base. |
+|`--dry`                                    | - or list | Show changes which would be made in files. Shows changes for provided filenames or shows all changes if no filename is specified. |
 |`--exclude`                                | list | Filenames (or path expressions), which will be completely skipped without being analysed. |
 |`--ignore-names`                           | list | Removes provided list of names from the output. Regexp expressions to match multiple names can also be provided, e.g. `*Mixin` will match all classes ending with `Mixin`. |
 |`--ignore-names-in-files`                  | list | Ignores unused names in files, which filenames match provided path expressions. |

deadcode/actions/parse_arguments.py

@@ -33,13 +33,13 @@ def parse_arguments(args: Optional[List[str]]) -> Args:
         action="store_true",
         default=False,
     )
-
     parser.add_argument(
-        "-v",
-        "--verbose",
-        help="Shows logs useful for debuging",
-        action="store_true",
-        default=False,
+        "--dry",
+        help="Show changes which would be made in files with --fix option.",
+        nargs="*",
+        action="append",
+        default=[["__all_files__"]],
+        type=str,
     )
     parser.add_argument(
         "--exclude",
@@ -160,24 +160,34 @@ def parse_arguments(args: Optional[List[str]]) -> Args:
         default=[],
         type=str,
     )
+
     parser.add_argument(
         "--no-color",
         help="Turn off colors in the output",
         action="store_true",
         default=False,
     )
+
     parser.add_argument(
         "--quiet",
         help="Does not output anything. Makefile still fails with exit code 1 if unused names are found.",
         action="store_true",
         default=False,
     )
+
     parser.add_argument(
         "--count",
         help="Provides the count of the detected unused names instead of printing them all out.",
         action="store_true",
         default=False,
     )
+    parser.add_argument(
+        "-v",
+        "--verbose",
+        help="Shows logs useful for debuging",
+        action="store_true",
+        default=False,
+    )
 
     parsed_args = parser.parse_args(args).__dict__
 
@@ -190,6 +200,14 @@ def parse_arguments(args: Optional[List[str]]) -> Args:
         if key in parsed_args:
             parsed_args[key].extend(item)
 
+    # Do not fix if dry option is provided:
+    if len(parsed_args["dry"]) > 1 or "--dry" not in args:
+        parsed_args["dry"].remove("__all_files__")
+
+    # Do not fix if dry option is provided:
+    if parsed_args["dry"]:
+        parsed_args["fix"] = False
+
     return Args(**parsed_args)
 
 

deadcode/data_types.py

@@ -13,6 +13,7 @@
 @dataclass
 class Args:
     fix: bool = False
+    dry: bool = False
     verbose: bool = False
     paths: Iterable[Pathname] = ()
     exclude: Iterable[Pathname] = ()

deadcode/tests/cli_args/test_parsing.py

@@ -20,47 +20,94 @@ def setUp(self):
         }
 
     def test_calling_with_one_paths_argument(self):
-        args = parse_arguments(["."])
+        options = "."
+        args = parse_arguments(options.split())
         self.assertEqual(args.paths, ["."])
         self.assertEqual(args.exclude, [])
         self.assertEqual(args.ignore_names, [])
         self.assertEqual(args.ignore_names_in_files, [])
 
     def test_calling_with_several_paths_argument(self):
-        args = parse_arguments([".", "tests"])
+        options = ". tests"
+        args = parse_arguments(options.split())
         self.assertEqual(args.paths, [".", "tests"])
         self.assertEqual(args.exclude, [])
         self.assertEqual(args.ignore_names, [])
         self.assertEqual(args.ignore_names_in_files, [])
 
     def test_calling_with_exclude(self):
-        args = parse_arguments([".", "--exclude=tests,venv"])
+        options = ". --exclude=tests,venv"
+        args = parse_arguments(options.split())
         self.assertEqual(args.paths, ["."])
         self.assertEqual(args.exclude, ["tests", "venv"])
         self.assertEqual(args.ignore_names, [])
         self.assertEqual(args.ignore_names_in_files, [])
 
     def test_calling_with_several_exclude_options(self):
-        args = parse_arguments([".", "--exclude=tests,venv", "--exclude=migrations"])
+        options = ". --exclude=tests,venv --exclude=migrations"
+        args = parse_arguments(options.split())
         self.assertEqual(args.paths, ["."])
         self.assertEqual(args.exclude, ["tests", "venv", "migrations"])
         self.assertEqual(args.ignore_names, [])
         self.assertEqual(args.ignore_names_in_files, [])
 
     def test_calling_with_no_color_option(self):
-        args = parse_arguments([".", "--no-color"])
+        options = ". --no-color"
+        args = parse_arguments(options.split())
         self.assertEqual(args.paths, ["."])
         self.assertEqual(args.no_color, True)
 
     def test_ignore_names_and_ignore_files_command_line_argument_parsing(self):
-        args = parse_arguments(
-            [
-                ".",
-                "--ignore-names-in-files=tests,venv",
-                "--ignore-names=BaseTestCase,lambda_handler",
-            ]
-        )
+        options = ". --ignore-names-in-files=tests,venv --ignore-names=BaseTestCase,lambda_handler"
+        args = parse_arguments(options.split())
         self.assertEqual(args.paths, ["."])
         self.assertEqual(args.exclude, [])
         self.assertEqual(args.ignore_names, ["BaseTestCase", "lambda_handler"])
         self.assertEqual(args.ignore_names_in_files, ["tests", "venv"])
+
+    def test_verbose_flag_is_on_using_long_name(self):
+        options = "--verbose ."
+        args = parse_arguments(options.split())
+        self.assertEqual(args.verbose, True)
+        self.assertEqual(args.paths, ["."])
+
+    def test_verbose_flag_is_on_using_short_name(self):
+        options = ". -v"
+        args = parse_arguments(options.split())
+        self.assertEqual(args.paths, ["."])
+        self.assertEqual(args.verbose, True)
+
+    def test_calling_with_fix(self):
+        options = ". --fix"
+        args = parse_arguments(options.split())
+        self.assertEqual(args.paths, ["."])
+        self.assertEqual(args.dry, [])
+        self.assertEqual(args.fix, True)
+
+    def test_calling_with_dry(self):
+        options = ". --dry --verbose"
+        args = parse_arguments(options.split())
+        self.assertEqual(args.paths, ["."])
+        self.assertEqual(args.dry, ["__all_files__"])
+        self.assertEqual(args.verbose, True)
+        self.assertEqual(args.fix, False)
+
+    def test_calling_with_fix_and_dry(self):
+        options = ". --dry --fix"
+        args = parse_arguments(options.split())
+        self.assertEqual(args.dry, ["__all_files__"])
+        self.assertEqual(args.fix, False)
+
+    def test_calling_with_single_dry_filename(self):
+        options = ". --dry foo.py --fix"
+        args = parse_arguments(options.split())
+        self.assertEqual(args.paths, ["."])
+        self.assertEqual(args.dry, ["foo.py"])
+        self.assertEqual(args.fix, False)
+
+    def test_calling_with_two_dry_filenames(self):
+        options = ". --fix --dry foo.py bar.py"
+        args = parse_arguments(options.split())
+        self.assertEqual(args.paths, ["."])
+        self.assertEqual(args.dry, ["foo.py", "bar.py"])
+        self.assertEqual(args.fix, False)