fastapi-route-loader/tests/test_loader.py

"""Tests for router loader."""

import sys
from pathlib import Path

import pytest
from fastapi import APIRouter

from fastapi_route_loader.loader import RouterLoader


class TestRouterLoader:
    """Test router loader functionality."""

    def test_is_router_with_api_router(self):
        router = APIRouter()
        assert RouterLoader._is_router(router) is True

    def test_is_router_with_non_router(self):
        assert RouterLoader._is_router("not a router") is False
        assert RouterLoader._is_router(123) is False
        assert RouterLoader._is_router(None) is False

    def test_get_module_path_without_package(self):
        base_path = Path("/app/routers")
        file_path = Path("/app/routers/users/api.py")
        module_path = RouterLoader._get_module_path(file_path, base_path, None)
        assert module_path == "users.api"

    def test_get_module_path_with_package(self):
        base_path = Path("/app/routers")
        file_path = Path("/app/routers/users/api.py")
        module_path = RouterLoader._get_module_path(file_path, base_path, "myapp")
        assert module_path == "myapp.users.api"

    def test_get_module_path_single_file(self):
        base_path = Path("/app/routers")
        file_path = Path("/app/routers/api.py")
        module_path = RouterLoader._get_module_path(file_path, base_path, None)
        assert module_path == "api"

    def test_load_from_module_success(self, tmp_path):
        module_content = '''
from fastapi import APIRouter

router = APIRouter()
other_router = APIRouter()
not_a_router = "test"
'''
        module_file = tmp_path / "test_module.py"
        module_file.write_text(module_content)

        sys.path.insert(0, str(tmp_path))
        try:
            routers = RouterLoader.load_from_module("test_module")
            assert "router" in routers
            assert "other_router" in routers
            assert "not_a_router" not in routers
            assert isinstance(routers["router"], APIRouter)
        finally:
            sys.path.remove(str(tmp_path))
            if "test_module" in sys.modules:
                del sys.modules["test_module"]

    def test_load_from_module_import_error(self):
        with pytest.raises(ImportError, match="Failed to import module"):
            RouterLoader.load_from_module("nonexistent_module_xyz")

    def test_load_from_directory_success(self, tmp_path):
        routers_dir = tmp_path / "routers"
        routers_dir.mkdir()

        (routers_dir / "__init__.py").write_text("")
        (routers_dir / "users.py").write_text(
            "from fastapi import APIRouter\nuser_router = APIRouter()"
        )
        (routers_dir / "posts.py").write_text(
            "from fastapi import APIRouter\npost_router = APIRouter()"
        )
        (routers_dir / "_private.py").write_text(
            "from fastapi import APIRouter\nprivate_router = APIRouter()"
        )

        sys.path.insert(0, str(tmp_path))
        try:
            routers = RouterLoader.load_from_directory(routers_dir, "routers")
            assert "users.user_router" in routers
            assert "posts.post_router" in routers
            assert "private.private_router" not in routers
        finally:
            sys.path.remove(str(tmp_path))
            for mod in list(sys.modules.keys()):
                if mod.startswith("routers"):
                    del sys.modules[mod]

    def test_load_from_directory_not_found(self):
        with pytest.raises(FileNotFoundError, match="Directory not found"):
            RouterLoader.load_from_directory("/nonexistent/path")

    def test_load_from_directory_not_a_directory(self, tmp_path):
        file_path = tmp_path / "not_a_dir.txt"
        file_path.write_text("test")

        with pytest.raises(NotADirectoryError, match="Not a directory"):
            RouterLoader.load_from_directory(file_path)

    def test_load_from_directory_nested_structure(self, tmp_path):
        routers_dir = tmp_path / "routers"
        routers_dir.mkdir()
        api_dir = routers_dir / "api"
        api_dir.mkdir()
        v1_dir = api_dir / "v1"
        v1_dir.mkdir()

        (routers_dir / "__init__.py").write_text("")
        (api_dir / "__init__.py").write_text("")
        (v1_dir / "__init__.py").write_text("")
        (v1_dir / "users.py").write_text(
            "from fastapi import APIRouter\nusers_router = APIRouter()"
        )

        sys.path.insert(0, str(tmp_path))
        try:
            routers = RouterLoader.load_from_directory(routers_dir, "routers")
            assert "users.users_router" in routers
        finally:
            sys.path.remove(str(tmp_path))
            for mod in list(sys.modules.keys()):
                if mod.startswith("routers"):
                    del sys.modules[mod]

    def test_load_from_directory_with_import_errors(self, tmp_path):
        routers_dir = tmp_path / "routers"
        routers_dir.mkdir()

        (routers_dir / "__init__.py").write_text("")
        (routers_dir / "good.py").write_text(
            "from fastapi import APIRouter\ngood_router = APIRouter()"
        )
        (routers_dir / "bad.py").write_text(
            "import nonexistent_module\nfrom fastapi import APIRouter\nbad_router = APIRouter()"
        )

        sys.path.insert(0, str(tmp_path))
        try:
            routers = RouterLoader.load_from_directory(routers_dir, "routers")
            assert "good.good_router" in routers
            assert "bad.bad_router" not in routers
        finally:
            sys.path.remove(str(tmp_path))
            for mod in list(sys.modules.keys()):
                if mod.startswith("routers"):
                    del sys.modules[mod]

    def test_load_from_directory_empty(self, tmp_path):
        routers_dir = tmp_path / "empty_routers"
        routers_dir.mkdir()

        routers = RouterLoader.load_from_directory(routers_dir)
        assert routers == {}