problems

problems/hard/rate-limiter/tests.py

@@ -0,0 +1,70 @@
+"""Tests for rate-limiter."""
+import pytest
+from solution import RateLimiter
+
+
+class TestBasicCases:
+    """Test basic functionality with typical inputs."""
+
+    def test_allow_within_limit(self):
+        """Test requests within the limit are allowed."""
+        limiter = RateLimiter(max_requests=3, window_seconds=60)
+        assert limiter.allow_request("user1", 0) == True
+        assert limiter.allow_request("user1", 30) == True
+        assert limiter.allow_request("user1", 45) == True
+
+    def test_block_over_limit(self):
+        """Test requests over limit are blocked."""
+        limiter = RateLimiter(max_requests=2, window_seconds=60)
+        assert limiter.allow_request("user1", 0) == True
+        assert limiter.allow_request("user1", 30) == True
+        assert limiter.allow_request("user1", 45) == False
+
+    def test_multiple_users_independent(self):
+        """Test each user has independent limits."""
+        limiter = RateLimiter(max_requests=1, window_seconds=60)
+        assert limiter.allow_request("user1", 0) == True
+        assert limiter.allow_request("user2", 0) == True
+        assert limiter.allow_request("user1", 30) == False
+        assert limiter.allow_request("user2", 30) == False
+
+    def test_get_remaining_basic(self):
+        """Test remaining count decreases with requests."""
+        limiter = RateLimiter(max_requests=3, window_seconds=60)
+        assert limiter.get_remaining("user1", 0) == 3
+        limiter.allow_request("user1", 0)
+        assert limiter.get_remaining("user1", 0) == 2
+
+
+class TestEdgeCases:
+    """Test edge cases and boundary conditions."""
+
+    def test_window_expiration(self):
+        """Test old requests expire from window."""
+        limiter = RateLimiter(max_requests=2, window_seconds=60)
+        assert limiter.allow_request("user1", 0) == True
+        assert limiter.allow_request("user1", 30) == True
+        assert limiter.allow_request("user1", 45) == False
+        assert limiter.allow_request("user1", 61) == True
+
+    def test_single_request_limit(self):
+        """Test with limit of 1 request."""
+        limiter = RateLimiter(max_requests=1, window_seconds=10)
+        assert limiter.allow_request("user1", 0) == True
+        assert limiter.allow_request("user1", 5) == False
+        assert limiter.allow_request("user1", 11) == True
+
+    def test_new_user_full_allowance(self):
+        """Test new users start with full allowance."""
+        limiter = RateLimiter(max_requests=5, window_seconds=60)
+        limiter.allow_request("user1", 0)
+        assert limiter.get_remaining("new_user", 20) == 5
+
+    def test_rapid_same_timestamp(self):
+        """Test multiple requests at same timestamp."""
+        limiter = RateLimiter(max_requests=3, window_seconds=1)
+        assert limiter.allow_request("user1", 0) == True
+        assert limiter.allow_request("user1", 0) == True
+        assert limiter.allow_request("user1", 0) == True
+        assert limiter.allow_request("user1", 0) == False
+