Files
fastapi-traffic/tests/test_algorithms.py

476 lines
15 KiB
Python

"""Tests for rate limiting algorithms.
Comprehensive tests covering:
- Basic allow/block behavior
- Limit boundaries and edge cases
- Token refill and window reset timing
- Concurrent access patterns
- State persistence and recovery
- Different key isolation
"""
from __future__ import annotations
import asyncio
from typing import TYPE_CHECKING
import pytest
from fastapi_traffic.backends.memory import MemoryBackend
from fastapi_traffic.core.algorithms import (
Algorithm,
FixedWindowAlgorithm,
LeakyBucketAlgorithm,
SlidingWindowAlgorithm,
SlidingWindowCounterAlgorithm,
TokenBucketAlgorithm,
get_algorithm,
)
if TYPE_CHECKING:
from collections.abc import AsyncGenerator
@pytest.fixture
async def backend() -> AsyncGenerator[MemoryBackend, None]:
"""Create a memory backend for testing."""
backend = MemoryBackend()
yield backend
await backend.close()
@pytest.mark.asyncio
class TestTokenBucketAlgorithm:
"""Tests for TokenBucketAlgorithm."""
async def test_allows_requests_within_limit(self, backend: MemoryBackend) -> None:
"""Test that requests within limit are allowed."""
algo = TokenBucketAlgorithm(10, 60.0, backend)
for i in range(10):
allowed, _ = await algo.check(f"key_{i % 2}")
assert allowed, f"Request {i} should be allowed"
async def test_blocks_requests_over_limit(self, backend: MemoryBackend) -> None:
"""Test that requests over limit are blocked."""
algo = TokenBucketAlgorithm(3, 60.0, backend)
for _ in range(3):
allowed, _ = await algo.check("test_key")
assert allowed
allowed, info = await algo.check("test_key")
assert not allowed
assert info.retry_after is not None
assert info.retry_after > 0
async def test_reset(self, backend: MemoryBackend) -> None:
"""Test reset functionality."""
algo = TokenBucketAlgorithm(3, 60.0, backend)
for _ in range(3):
await algo.check("test_key")
allowed, _ = await algo.check("test_key")
assert not allowed
await algo.reset("test_key")
allowed, _ = await algo.check("test_key")
assert allowed
@pytest.mark.asyncio
class TestSlidingWindowAlgorithm:
"""Tests for SlidingWindowAlgorithm."""
async def test_allows_requests_within_limit(self, backend: MemoryBackend) -> None:
"""Test that requests within limit are allowed."""
algo = SlidingWindowAlgorithm(5, 60.0, backend)
for _ in range(5):
allowed, _ = await algo.check("test_key")
assert allowed
async def test_blocks_requests_over_limit(self, backend: MemoryBackend) -> None:
"""Test that requests over limit are blocked."""
algo = SlidingWindowAlgorithm(3, 60.0, backend)
for _ in range(3):
allowed, _ = await algo.check("test_key")
assert allowed
allowed, info = await algo.check("test_key")
assert not allowed
assert info.remaining == 0
@pytest.mark.asyncio
class TestFixedWindowAlgorithm:
"""Tests for FixedWindowAlgorithm."""
async def test_allows_requests_within_limit(self, backend: MemoryBackend) -> None:
"""Test that requests within limit are allowed."""
algo = FixedWindowAlgorithm(5, 60.0, backend)
for _ in range(5):
allowed, _ = await algo.check("test_key")
assert allowed
async def test_blocks_requests_over_limit(self, backend: MemoryBackend) -> None:
"""Test that requests over limit are blocked."""
algo = FixedWindowAlgorithm(3, 60.0, backend)
for _ in range(3):
allowed, _ = await algo.check("test_key")
assert allowed
allowed, info = await algo.check("test_key")
assert not allowed
assert info.remaining == 0
@pytest.mark.asyncio
class TestLeakyBucketAlgorithm:
"""Tests for LeakyBucketAlgorithm."""
async def test_allows_requests_within_limit(self, backend: MemoryBackend) -> None:
"""Test that requests within limit are allowed."""
algo = LeakyBucketAlgorithm(5, 60.0, backend)
for _ in range(5):
allowed, _ = await algo.check("test_key")
assert allowed
async def test_blocks_requests_over_limit(self, backend: MemoryBackend) -> None:
"""Test that requests over limit are blocked."""
algo = LeakyBucketAlgorithm(3, 60.0, backend)
# Leaky bucket allows burst_size requests initially
for _ in range(3):
allowed, _ = await algo.check("test_key")
assert allowed
# After burst, should eventually block
# Note: Leaky bucket behavior depends on leak rate
allowed, info = await algo.check("test_key")
# Just verify we get valid info back
assert info.limit == 3
@pytest.mark.asyncio
class TestSlidingWindowCounterAlgorithm:
"""Tests for SlidingWindowCounterAlgorithm."""
async def test_allows_requests_within_limit(self, backend: MemoryBackend) -> None:
"""Test that requests within limit are allowed."""
algo = SlidingWindowCounterAlgorithm(5, 60.0, backend)
for _ in range(5):
allowed, _ = await algo.check("test_key")
assert allowed
async def test_blocks_requests_over_limit(self, backend: MemoryBackend) -> None:
"""Test that requests over limit are blocked."""
algo = SlidingWindowCounterAlgorithm(3, 60.0, backend)
for _ in range(3):
allowed, _ = await algo.check("test_key")
assert allowed
allowed, _ = await algo.check("test_key")
assert not allowed
@pytest.mark.asyncio
class TestGetAlgorithm:
"""Tests for get_algorithm factory function."""
async def test_get_token_bucket(self, backend: MemoryBackend) -> None:
"""Test getting token bucket algorithm."""
algo = get_algorithm(Algorithm.TOKEN_BUCKET, 10, 60.0, backend)
assert isinstance(algo, TokenBucketAlgorithm)
async def test_get_sliding_window(self, backend: MemoryBackend) -> None:
"""Test getting sliding window algorithm."""
algo = get_algorithm(Algorithm.SLIDING_WINDOW, 10, 60.0, backend)
assert isinstance(algo, SlidingWindowAlgorithm)
async def test_get_fixed_window(self, backend: MemoryBackend) -> None:
"""Test getting fixed window algorithm."""
algo = get_algorithm(Algorithm.FIXED_WINDOW, 10, 60.0, backend)
assert isinstance(algo, FixedWindowAlgorithm)
async def test_get_leaky_bucket(self, backend: MemoryBackend) -> None:
"""Test getting leaky bucket algorithm."""
algo = get_algorithm(Algorithm.LEAKY_BUCKET, 10, 60.0, backend)
assert isinstance(algo, LeakyBucketAlgorithm)
async def test_get_sliding_window_counter(self, backend: MemoryBackend) -> None:
"""Test getting sliding window counter algorithm."""
algo = get_algorithm(Algorithm.SLIDING_WINDOW_COUNTER, 10, 60.0, backend)
assert isinstance(algo, SlidingWindowCounterAlgorithm)
@pytest.mark.asyncio
class TestTokenBucketAdvanced:
"""Advanced tests for TokenBucketAlgorithm."""
async def test_token_refill_over_time(self, backend: MemoryBackend) -> None:
"""Test that tokens refill after time passes."""
algo = TokenBucketAlgorithm(5, 1.0, backend)
for _ in range(5):
allowed, _ = await algo.check("refill_key")
assert allowed
allowed, _ = await algo.check("refill_key")
assert not allowed
await asyncio.sleep(0.3)
allowed, _ = await algo.check("refill_key")
assert allowed
async def test_burst_size_configuration(self, backend: MemoryBackend) -> None:
"""Test that burst_size limits initial tokens."""
algo = TokenBucketAlgorithm(100, 60.0, backend, burst_size=5)
for i in range(5):
allowed, _ = await algo.check("burst_key")
assert allowed, f"Request {i} should be allowed"
allowed, _ = await algo.check("burst_key")
assert not allowed
async def test_key_isolation(self, backend: MemoryBackend) -> None:
"""Test that different keys have separate limits."""
algo = TokenBucketAlgorithm(3, 60.0, backend)
for _ in range(3):
await algo.check("key_a")
allowed_a, _ = await algo.check("key_a")
assert not allowed_a
allowed_b, _ = await algo.check("key_b")
assert allowed_b
async def test_concurrent_requests(self, backend: MemoryBackend) -> None:
"""Test concurrent request handling."""
algo = TokenBucketAlgorithm(10, 60.0, backend)
async def make_request() -> bool:
allowed, _ = await algo.check("concurrent_key")
return allowed
results = await asyncio.gather(*[make_request() for _ in range(15)])
allowed_count = sum(results)
assert allowed_count == 10
async def test_rate_limit_info_accuracy(self, backend: MemoryBackend) -> None:
"""Test that rate limit info is accurate."""
algo = TokenBucketAlgorithm(5, 60.0, backend)
allowed, info = await algo.check("info_key")
assert allowed
assert info.limit == 5
assert info.remaining == 4
for _ in range(4):
await algo.check("info_key")
allowed, info = await algo.check("info_key")
assert not allowed
assert info.remaining == 0
assert info.retry_after is not None
assert info.retry_after > 0
@pytest.mark.asyncio
class TestSlidingWindowAdvanced:
"""Advanced tests for SlidingWindowAlgorithm."""
async def test_window_expiration(self, backend: MemoryBackend) -> None:
"""Test that old requests expire from the window."""
algo = SlidingWindowAlgorithm(3, 0.5, backend)
for _ in range(3):
allowed, _ = await algo.check("expire_key")
assert allowed
allowed, _ = await algo.check("expire_key")
assert not allowed
await asyncio.sleep(0.6)
allowed, _ = await algo.check("expire_key")
assert allowed
async def test_sliding_behavior(self, backend: MemoryBackend) -> None:
"""Test that window slides correctly."""
algo = SlidingWindowAlgorithm(2, 1.0, backend)
allowed, _ = await algo.check("slide_key")
assert allowed
await asyncio.sleep(0.3)
allowed, _ = await algo.check("slide_key")
assert allowed
allowed, _ = await algo.check("slide_key")
assert not allowed
await asyncio.sleep(0.8)
allowed, _ = await algo.check("slide_key")
assert allowed
@pytest.mark.asyncio
class TestFixedWindowAdvanced:
"""Advanced tests for FixedWindowAlgorithm."""
async def test_window_boundary_reset(self, backend: MemoryBackend) -> None:
"""Test that counter resets at window boundary."""
algo = FixedWindowAlgorithm(3, 0.5, backend)
for _ in range(3):
allowed, _ = await algo.check("boundary_key")
assert allowed
allowed, _ = await algo.check("boundary_key")
assert not allowed
await asyncio.sleep(0.6)
allowed, _ = await algo.check("boundary_key")
assert allowed
async def test_multiple_windows(self, backend: MemoryBackend) -> None:
"""Test behavior across multiple windows."""
algo = FixedWindowAlgorithm(2, 0.3, backend)
for _ in range(2):
allowed, _ = await algo.check("multi_key")
assert allowed
allowed, _ = await algo.check("multi_key")
assert not allowed
await asyncio.sleep(0.35)
for _ in range(2):
allowed, _ = await algo.check("multi_key")
assert allowed
@pytest.mark.asyncio
class TestLeakyBucketAdvanced:
"""Advanced tests for LeakyBucketAlgorithm."""
async def test_leak_rate(self, backend: MemoryBackend) -> None:
"""Test that bucket leaks over time."""
algo = LeakyBucketAlgorithm(3, 1.0, backend)
# Make initial requests
for _ in range(3):
allowed, _ = await algo.check("leak_key")
assert allowed
# Wait for some leaking to occur
await asyncio.sleep(0.5)
# Should be able to make another request after leak
allowed, info = await algo.check("leak_key")
assert info.limit == 3
async def test_steady_rate_enforcement(self, backend: MemoryBackend) -> None:
"""Test that leaky bucket tracks requests."""
algo = LeakyBucketAlgorithm(5, 1.0, backend)
# Make several requests
for _ in range(5):
allowed, info = await algo.check("steady_key")
assert allowed
assert info.limit == 5
@pytest.mark.asyncio
class TestSlidingWindowCounterAdvanced:
"""Advanced tests for SlidingWindowCounterAlgorithm."""
async def test_weighted_counting(self, backend: MemoryBackend) -> None:
"""Test weighted counting between windows."""
algo = SlidingWindowCounterAlgorithm(10, 1.0, backend)
for _ in range(8):
allowed, _ = await algo.check("weighted_key")
assert allowed
await asyncio.sleep(0.6)
allowed, info = await algo.check("weighted_key")
assert allowed
assert info.remaining > 0
async def test_precision_vs_fixed_window(self, backend: MemoryBackend) -> None:
"""Test that sliding window counter is more precise than fixed window."""
algo = SlidingWindowCounterAlgorithm(4, 1.0, backend)
for _ in range(4):
allowed, _ = await algo.check("precision_key")
assert allowed
allowed, _ = await algo.check("precision_key")
assert not allowed
# Wait for the full window to pass to ensure tokens are fully replenished
await asyncio.sleep(1.1)
allowed, _ = await algo.check("precision_key")
assert allowed
@pytest.mark.asyncio
class TestAlgorithmStateManagement:
"""Tests for algorithm state management."""
async def test_get_state_without_consuming(self, backend: MemoryBackend) -> None:
"""Test getting state without consuming tokens."""
algo = TokenBucketAlgorithm(5, 60.0, backend)
await algo.check("state_key")
await algo.check("state_key")
state = await algo.get_state("state_key")
assert state is not None
assert state.remaining == 3
state2 = await algo.get_state("state_key")
assert state2 is not None
assert state2.remaining == 3
async def test_get_state_nonexistent_key(self, backend: MemoryBackend) -> None:
"""Test getting state for nonexistent key."""
algo = TokenBucketAlgorithm(5, 60.0, backend)
state = await algo.get_state("nonexistent_key")
assert state is None
async def test_reset_restores_full_capacity(self, backend: MemoryBackend) -> None:
"""Test that reset restores full capacity."""
algo = TokenBucketAlgorithm(5, 60.0, backend)
for _ in range(5):
await algo.check("reset_key")
allowed, _ = await algo.check("reset_key")
assert not allowed
await algo.reset("reset_key")
allowed, info = await algo.check("reset_key")
assert allowed
assert info.remaining == 4