Add --allow-nested flag to permit nested dummy repos and refactor tangential code

Signed-off-by: Jacob Stopak <jacob@initialcommit.io>

Author: initialcommit-io

README.md

@@ -66,7 +66,8 @@ Available options and flags include:
 `--merge`: A comma separated list of branch postfix ids to merge back into `main`.  
 `--git-dir`: The path at which to store the dummy Git repo, defaults to current directory.  
 `--no-subdir`: Initialize the dummy Git repo in the current directory instead of in a subdirectory.  
-`--constant_sha`: Use constant values for commit author, email, and commit date parameters to yield consistent sha1 values across git-dummy runs.
+`--constant_sha`: Use constant values for commit author, email, and commit date parameters to yield consistent sha1 values across git-dummy runs.  
+`--allow-nested`: Allow dummy repo creation within an existing Git repo, as long as it's not at the level of an existing .git/ folder.
 
 ## Command examples
 Generate a dummy Git repo called "cheese" on your Desktop, with 2 branches and 10 commits on each branch:

git_dummy/__main__.py

@@ -6,6 +6,12 @@
 import sys
 
 from git_dummy.settings import settings
+from git_dummy.util import (
+    is_dir_exist,
+    is_git_dir,
+    is_inside_git_dir,
+    is_valid_folder_name,
+)
 
 
 app = typer.Typer(context_settings={"help_option_names": ["-h", "--help"]})
@@ -16,6 +22,7 @@ def main(
     name: str = typer.Option(
         settings.name,
         help="Name of the dummy repo",
+        callback=is_valid_folder_name,
     ),
     git_dir: pathlib.Path = typer.Option(
         settings.git_dir,
@@ -45,6 +52,10 @@ def main(
         settings.constant_sha,
         help="Use constant values for commit author, email, and commit date parameters to yield consistent sha1 values across git-dummy runs",
     ),
+    allow_nested: bool = typer.Option(
+        settings.allow_nested,
+        help="Allow dummy repo creation within an existing Git repo, as long as it's not at the level of an existing .git/ folder",
+    ),
 ):
     settings.name = name
     settings.commits = commits
@@ -53,28 +64,25 @@ def main(
     settings.merge = merge
     settings.no_subdir = no_subdir
     settings.constant_sha = constant_sha
+    settings.allow_nested = allow_nested
 
     settings.git_dir = os.path.expanduser(git_dir)
     if not settings.no_subdir:
         settings.git_dir = os.path.join(settings.git_dir, settings.name)
 
-    try:
-        git.Repo(settings.git_dir, search_parent_directories=True)
+    if is_git_dir(settings.git_dir):
+        print(f"git-dummy error: Git repository already exists at {settings.git_dir}")
+        sys.exit(1)
+
+    if not settings.allow_nested and is_inside_git_dir(settings.git_dir):
         print(
-            f"git-dummy error: Git repository already exists at {settings.git_dir} or parent"
+            f"git-dummy error: Git repository already exists at {settings.git_dir} or parent: use --allow-nested flag to override"
         )
         sys.exit(1)
-    except (git.exc.InvalidGitRepositoryError, git.exc.NoSuchPathError):
-        try:
-            git.Repo(pathlib.Path().cwd(), search_parent_directories=True)
-            print(
-                f"git-dummy error: Git repository already exists at {settings.git_dir} or parent"
-            )
-            sys.exit(1)
-        except git.exc.InvalidGitRepositoryError:
-            print(
-                f"git-dummy: Generating dummy Git repo at {settings.git_dir} with {settings.branches} branch(es) and {settings.commits} commit(s)."
-            )
+
+    print(
+        f"git-dummy: Generating dummy Git repo at {settings.git_dir} with {settings.branches} branch(es) and {settings.commits} commit(s)."
+    )
 
     repo = git.Repo.init(settings.git_dir, initial_branch="main")
 

git_dummy/settings.py

@@ -11,6 +11,7 @@ class Settings(BaseSettings):
     merge: str = ""
     no_subdir: bool = False
     constant_sha: bool = False
+    allow_nested: bool = False
 
     class Config:
         env_prefix = "git_dummy_"

git_dummy/util.py

@@ -0,0 +1,44 @@
+import git
+import os
+import typer
+
+
+def is_dir_exist(path):
+    if os.path.exists(path) and os.path.isdir(path):
+        return True
+    return False
+
+
+def is_git_dir(path):
+    try:
+        git.Repo(path)
+        return True
+    except (git.exc.InvalidGitRepositoryError, git.exc.NoSuchPathError):
+        return False
+
+
+def is_inside_git_dir(path):
+    while not is_dir_exist(path):
+        try:
+            git.Repo(path, search_parent_directories=True)
+            return True
+        except (git.exc.InvalidGitRepositoryError, git.exc.NoSuchPathError):
+            path = os.path.dirname(path)
+    else:
+        try:
+            git.Repo(path, search_parent_directories=True)
+            return True
+        except (git.exc.InvalidGitRepositoryError, git.exc.NoSuchPathError):
+            return False
+
+
+def is_valid_folder_name(name):
+    allowed_characters = (
+        "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_"
+    )
+    is_valid = all(char in set(allowed_characters) for char in name)
+    if not is_valid:
+        raise typer.BadParameter(
+            f"only the following characters are permitted in the directory name: {allowed_characters}"
+        )
+    return name