feat: Add support for optional LICENSE file in project generation

Author: kpatryk

.github/instructions/copier.instructions.md

@@ -15,6 +15,9 @@ Quick reference for the `copier` project templating tool.
 - **Settings:** https://copier.readthedocs.io/en/stable/settings/
 - **FAQ:** https://copier.readthedocs.io/en/stable/faq/
 
+# LICENSE file
+- The type of LICENSEs supported can be found here: https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/licensing-a-repository#choosing-the-right-license
+
 ## Key Concepts
 - Use `copier copy` to generate projects from templates
 - Use `copier update` to sync existing projects with template changes

copier.yaml

@@ -34,6 +34,11 @@ dev_deps:
     help: "Enter development dependencies as a JSON array"
     default: ["pytest", "pytest-cov", "ruff"]
 
+include_license:
+    type: bool
+    help: "Include a LICENSE file in the project?"
+    default: false
+
 _templates_suffix: .jinja
 _envops:
     block_start_string: "{%"

my_tests/test_optional_license.py

@@ -0,0 +1,47 @@
+"""Test LICENSE file is optional and excluded by default."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+from conftest import _make_data, _run_copy
+
+
+@pytest.fixture(scope="module")
+def generated_without_license() -> Path:
+    """Generate project without LICENSE file (default behavior)."""
+    data = _make_data({"project_name": "no_license_proj", "include_license": False})
+    return _run_copy(data, dst_name="no_license")
+
+
+@pytest.fixture(scope="module")
+def generated_with_license() -> Path:
+    """Generate project with LICENSE file explicitly requested."""
+    data = _make_data(
+        {
+            "project_name": "with_license_proj",
+            "include_license": True,
+        }
+    )
+    return _run_copy(data, dst_name="with_license")
+
+
+def test_license_excluded_by_default(generated_without_license: Path):
+    """Test that LICENSE file is NOT included when include_license=false (default)."""
+    license_path = generated_without_license / "LICENSE"
+    assert not license_path.exists(), "LICENSE should not exist when include_license=false (default)"
+
+
+def test_license_included_when_requested(generated_with_license: Path):
+    """Test that LICENSE file IS included when include_license=true."""
+    license_path = generated_with_license / "LICENSE"
+    assert license_path.is_file(), "LICENSE should exist when include_license=true"
+
+
+def test_license_content_matches_template(generated_with_license: Path):
+    """Test that generated LICENSE file contains expected content."""
+    license_path = generated_with_license / "LICENSE"
+    content = license_path.read_text()
+    assert "MIT License" in content, "LICENSE should contain MIT License header"
+    assert "Copyright" in content, "LICENSE should contain copyright notice"