Initial commit: fastapi-traffic rate limiting library

- Core rate limiting with multiple algorithms (sliding window, token bucket, etc.)
- SQLite and memory backends
- Decorator and dependency injection patterns
- Middleware support
- Example usage files

tests/test_backends.py

@@ -0,0 +1,143 @@
+"""Tests for rate limit backends."""
+
+from __future__ import annotations
+
+import asyncio
+from typing import AsyncGenerator
+
+import pytest
+
+from fastapi_traffic.backends.memory import MemoryBackend
+from fastapi_traffic.backends.sqlite import SQLiteBackend
+
+
+class TestMemoryBackend:
+    """Tests for MemoryBackend."""
+
+    @pytest.fixture
+    async def backend(self) -> AsyncGenerator[MemoryBackend, None]:
+        """Create a memory backend for testing."""
+        backend = MemoryBackend(max_size=100, cleanup_interval=1.0)
+        yield backend
+        await backend.close()
+
+    async def test_set_and_get(self, backend: MemoryBackend) -> None:
+        """Test basic set and get operations."""
+        await backend.set("test_key", {"count": 5}, ttl=60.0)
+        result = await backend.get("test_key")
+        assert result is not None
+        assert result["count"] == 5
+
+    async def test_get_nonexistent(self, backend: MemoryBackend) -> None:
+        """Test getting a nonexistent key."""
+        result = await backend.get("nonexistent")
+        assert result is None
+
+    async def test_delete(self, backend: MemoryBackend) -> None:
+        """Test delete operation."""
+        await backend.set("test_key", {"count": 5}, ttl=60.0)
+        await backend.delete("test_key")
+        result = await backend.get("test_key")
+        assert result is None
+
+    async def test_exists(self, backend: MemoryBackend) -> None:
+        """Test exists operation."""
+        assert not await backend.exists("test_key")
+        await backend.set("test_key", {"count": 5}, ttl=60.0)
+        assert await backend.exists("test_key")
+
+    async def test_increment(self, backend: MemoryBackend) -> None:
+        """Test increment operation."""
+        await backend.set("test_key", {"count": 5}, ttl=60.0)
+        result = await backend.increment("test_key", 3)
+        assert result == 8
+
+    async def test_clear(self, backend: MemoryBackend) -> None:
+        """Test clear operation."""
+        await backend.set("key1", {"count": 1}, ttl=60.0)
+        await backend.set("key2", {"count": 2}, ttl=60.0)
+        await backend.clear()
+        assert not await backend.exists("key1")
+        assert not await backend.exists("key2")
+
+    async def test_ttl_expiration(self, backend: MemoryBackend) -> None:
+        """Test that entries expire after TTL."""
+        await backend.set("test_key", {"count": 5}, ttl=0.1)
+        await asyncio.sleep(0.2)
+        result = await backend.get("test_key")
+        assert result is None
+
+    async def test_lru_eviction(self) -> None:
+        """Test LRU eviction when max size is reached."""
+        backend = MemoryBackend(max_size=3)
+        try:
+            await backend.set("key1", {"v": 1}, ttl=60.0)
+            await backend.set("key2", {"v": 2}, ttl=60.0)
+            await backend.set("key3", {"v": 3}, ttl=60.0)
+            await backend.set("key4", {"v": 4}, ttl=60.0)
+
+            assert not await backend.exists("key1")
+            assert await backend.exists("key2")
+            assert await backend.exists("key3")
+            assert await backend.exists("key4")
+        finally:
+            await backend.close()
+
+
+class TestSQLiteBackend:
+    """Tests for SQLiteBackend."""
+
+    @pytest.fixture
+    async def backend(self) -> AsyncGenerator[SQLiteBackend, None]:
+        """Create an in-memory SQLite backend for testing."""
+        backend = SQLiteBackend(":memory:", cleanup_interval=1.0)
+        await backend.initialize()
+        yield backend
+        await backend.close()
+
+    async def test_set_and_get(self, backend: SQLiteBackend) -> None:
+        """Test basic set and get operations."""
+        await backend.set("test_key", {"count": 5}, ttl=60.0)
+        result = await backend.get("test_key")
+        assert result is not None
+        assert result["count"] == 5
+
+    async def test_get_nonexistent(self, backend: SQLiteBackend) -> None:
+        """Test getting a nonexistent key."""
+        result = await backend.get("nonexistent")
+        assert result is None
+
+    async def test_delete(self, backend: SQLiteBackend) -> None:
+        """Test delete operation."""
+        await backend.set("test_key", {"count": 5}, ttl=60.0)
+        await backend.delete("test_key")
+        result = await backend.get("test_key")
+        assert result is None
+
+    async def test_exists(self, backend: SQLiteBackend) -> None:
+        """Test exists operation."""
+        assert not await backend.exists("test_key")
+        await backend.set("test_key", {"count": 5}, ttl=60.0)
+        assert await backend.exists("test_key")
+
+    async def test_increment(self, backend: SQLiteBackend) -> None:
+        """Test increment operation."""
+        await backend.set("test_key", {"count": 5}, ttl=60.0)
+        result = await backend.increment("test_key", 3)
+        assert result == 8
+
+    async def test_clear(self, backend: SQLiteBackend) -> None:
+        """Test clear operation."""
+        await backend.set("key1", {"count": 1}, ttl=60.0)
+        await backend.set("key2", {"count": 2}, ttl=60.0)
+        await backend.clear()
+        assert not await backend.exists("key1")
+        assert not await backend.exists("key2")
+
+    async def test_get_stats(self, backend: SQLiteBackend) -> None:
+        """Test get_stats operation."""
+        await backend.set("key1", {"count": 1}, ttl=60.0)
+        await backend.set("key2", {"count": 2}, ttl=60.0)
+        stats = await backend.get_stats()
+        assert stats["total_entries"] == 2
+        assert stats["active_entries"] == 2