feat(naming): prevent invalid project names

hooks/pre_gen_project.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+"""
+Pre-project generation hook for validation
+"""
+
+import re
+import sys
+from logging import basicConfig, getLogger
+
+basicConfig(level="WARNING", format="%(levelname)s: %(message)s")
+LOG = getLogger("pre_generation_hook")
+
+# Cookiecutter variables
+PROJECT_NAME = "{{ cookiecutter.project_name }}"
+PROJECT_SLUG = "{{ cookiecutter.project_slug }}"
+
+
+def validate_project_name() -> None:
+    """Validate that project_name starts with an alphabetical character."""
+    # Check if project_name starts with an alphabetical character
+    if not re.match(r"^[a-zA-Z]", PROJECT_NAME):
+        LOG.error(
+            "Invalid project name '%s': Python project names must start with an alphabetical character (a-z or A-Z).",
+            PROJECT_NAME,
+        )
+        sys.exit(1)
+
+
+def validate_project_slug() -> None:
+    """Validate that project_slug is a valid Python identifier."""
+    # Check if project_slug is a valid Python identifier
+    if not PROJECT_SLUG.isidentifier():
+        LOG.error("Invalid project slug '%s': Must be a valid Python identifier.", PROJECT_SLUG)
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    validate_project_name()
+    validate_project_slug()

tests/test_cookiecutter.py

@@ -211,6 +211,53 @@ def test_autofix_hook(cookies, context):
             pytest.fail(f"stdout: {error.stdout.decode('utf-8')}, stderr: {error.stderr.decode('utf-8')}")
 
 
+@pytest.mark.unit
+@pytest.mark.parametrize(
+    "invalid_name",
+    [
+        "123invalid",  # starts with number
+        "_invalid",  # starts with underscore
+        "-invalid",  # starts with dash
+        "9project",  # starts with number
+        "!invalid",  # starts with special character
+    ],
+)
+def test_invalid_project_name_validation(cookies, invalid_name):
+    """
+    Test that project names starting with non-alphabetical characters are rejected
+    """
+    result = cookies.bake(extra_context={"project_name": invalid_name})
+
+    # The generation should fail due to validation
+    assert result.exit_code != 0, f"Expected validation failure for project name: {invalid_name}"
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize(
+    "valid_name",
+    [
+        "ValidProject",  # starts with uppercase
+        "validproject",  # starts with lowercase
+        "My Project",  # starts with uppercase, has space
+        "a1234",  # starts with lowercase, has numbers
+        "Z_project",  # starts with uppercase, has underscore
+    ],
+)
+def test_valid_project_name_validation(cookies, valid_name):
+    """
+    Test that valid project names starting with alphabetical characters are accepted
+    """
+    # Turn off the post generation hooks for faster testing
+    os.environ["RUN_POST_HOOK"] = "false"
+
+    result = cookies.bake(extra_context={"project_name": valid_name})
+
+    # The generation should succeed
+    assert result.exit_code == 0, f"Expected validation success for project name: {valid_name}"
+    assert result.exception is None
+    assert result.project_path.is_dir()
+
+
 @pytest.mark.integration
 @pytest.mark.slow
 def test_default_project(cookies):