Add 'init' command to cli with separate arg parsing

modguard/cli.py

@@ -2,6 +2,7 @@
 import os
 import sys
 from modguard.check import check, ErrorInfo
+from modguard.init import init_project
 
 
 class BCOLORS:
@@ -39,17 +40,37 @@ def print_invalid_exclude(path: str) -> None:
     )
 
 
-def build_parser() -> argparse.ArgumentParser:
-    parser = argparse.ArgumentParser(
+def parse_base_arguments(args) -> argparse.Namespace:
+    base_parser = argparse.ArgumentParser(
         prog="modguard",
-        description="Verify module boundaries are correctly implemented.",
+        add_help=True,
         epilog="Make sure modguard is run from the root of your repo that a directory is being specified. For example: `modguard .`",
     )
+    base_parser.add_argument(
+        "path",
+        type=str,
+        help="The path of the root of your project that contains all defined boundaries.",
+    )
+    base_parser.add_argument(
+        "-e",
+        "--exclude",
+        required=False,
+        type=str,
+        metavar="file_or_path,...",
+        help="Comma separated path list to exclude. tests/,ci/,etc.",
+    )
+    return base_parser.parse_args(args)
 
+
+def parse_init_arguments(args) -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        prog="modguard init",
+        description="Initialize boundaries in a repository with modguard",
+    )
     parser.add_argument(
         "path",
         type=str,
-        help="The path of the root of your project that contains all defined boundaries.",
+        help="The path of the Python project in which boundaries should be initialized.",
     )
     parser.add_argument(
         "-e",
@@ -59,10 +80,11 @@ def build_parser() -> argparse.ArgumentParser:
         metavar="file_or_path,...",
         help="Comma separated path list to exclude. tests/,ci/,etc.",
     )
-    return parser
+
+    return parser.parse_args(args)
 
 
-def main(args: argparse.Namespace):
+def handle_shared_arguments(args: argparse.Namespace):
     path = args.path
     if not os.path.isdir(path):
         print_invalid_path(path)
@@ -80,19 +102,46 @@ def main(args: argparse.Namespace):
                 print_invalid_exclude(exclude_path)
         if has_error:
             sys.exit(1)
-    result: list[ErrorInfo] = check(path, exclude_paths=exclude_paths)
+
+    return argparse.Namespace(path=path, exclude_paths=exclude_paths)
+
+
+def modguard(args: argparse.Namespace):
+    shared_args = handle_shared_arguments(args)
+    try:
+        result: list[ErrorInfo] = check(
+            shared_args.path, exclude_paths=shared_args.exclude_paths
+        )
+    except Exception as e:
+        print(str(e))
+        sys.exit(1)
+
     if result:
         print_errors(result)
         sys.exit(1)
     print(f"✅ {BCOLORS.OKGREEN}All modules safely guarded!")
     sys.exit(0)
 
 
-def modguard() -> None:
-    parser = build_parser()
-    args = parser.parse_args()
-    main(args)
+def modguard_init(args: argparse.Namespace):
+    shared_args = handle_shared_arguments(args)
+
+    try:
+        init_project(shared_args.path, exclude_paths=shared_args.exclude_paths)
+    except Exception as e:
+        print(str(e))
+        sys.exit(1)
+
+    print(f"✅ {BCOLORS.OKGREEN}Modguard initialized.")
+    sys.exit(0)
+
+
+def main() -> None:
+    if len(sys.argv) > 1 and sys.argv[1] == "init":
+        modguard_init(parse_init_arguments(sys.argv[2:]))
+    else:
+        modguard(parse_base_arguments(sys.argv[1:]))
 
 
 if __name__ == "__main__":
-    modguard()
+    main()

modguard/init.py

@@ -1,5 +1,5 @@
 import os
-import errors
+from . import errors
 from .check import check_import
 from .core import PublicMember
 from .parsing import utils
@@ -21,7 +21,9 @@ def init_project(root: str, exclude_paths: list[str] = None):
     exclude_paths = list(map(utils.canonical, exclude_paths)) if exclude_paths else None
 
     boundary_trie = build_boundary_trie(root, exclude_paths=exclude_paths)
-    initial_boundary_paths = [boundary.full_path for boundary in boundary_trie]
+    initial_boundary_paths = [
+        boundary.full_path for boundary in boundary_trie if boundary.full_path
+    ]
 
     for dirpath in utils.walk_pypackages(root, exclude_paths=exclude_paths):
         added_boundary = ensure_boundary(dirpath + "/__init__.py")
@@ -58,5 +60,10 @@ def init_project(root: str, exclude_paths: list[str] = None):
                 continue
 
             file_path, member_name = utils.module_to_file_path(import_mod_path)
-            mark_as_public(file_path, member_name)
-            violated_boundary.add_public_member(PublicMember(name=import_mod_path))
+            try:
+                mark_as_public(file_path, member_name)
+                violated_boundary.add_public_member(PublicMember(name=import_mod_path))
+            except errors.ModguardParseError:
+                print(
+                    f"Skipping member {member_name} in {file_path}; could not mark as public"
+                )

modguard/parsing/public.py

@@ -171,7 +171,7 @@ def _public_module_prelude(should_import: bool = True) -> str:
 
 
 IMPORT_MODGUARD = "import modguard"
-PUBLIC_DECORATOR = "@public"
+PUBLIC_DECORATOR = "@modguard.public"
 
 
 @public
@@ -204,13 +204,13 @@ def mark_as_public(file_path: str, member_name: str = ""):
         )
 
     with open(file_path, "w") as file:
-        file_lines = file_content.splitlines()
+        file_lines = file_content.splitlines(keepends=True)
         lines_to_write = [
             *file_lines[: member_finder.matched_lineno - 1],
-            PUBLIC_DECORATOR,
+            PUBLIC_DECORATOR + "\n",
             *file_lines[member_finder.matched_lineno - 1 :],
         ]
         if not modguard_public_is_imported:
-            lines_to_write = [IMPORT_MODGUARD, *lines_to_write]
+            lines_to_write = [IMPORT_MODGUARD + "\n", *lines_to_write]
 
-        file.write("\n".join(lines_to_write))
+        file.write("".join(lines_to_write))

modguard/parsing/utils.py

@@ -73,7 +73,7 @@ def module_to_file_path(
     last_sep_index = fs_path.rfind(os.path.sep)
     file_path = fs_path[:last_sep_index] + ".py"
     if os.path.exists(file_path):
-        member_name = fs_path[last_sep_index:]
+        member_name = fs_path[last_sep_index + 1 :]
         return file_path, member_name
 
     raise errors.ModguardParseError(

pyproject.toml

@@ -37,4 +37,4 @@ requires = ["setuptools>=61.0"]
 build-backend = "setuptools.build_meta"
 
 [project.scripts]
-modguard = "modguard.cli:modguard"
+modguard = "modguard.cli:main"