Background Prefetching for Kavita+ (#2707)

API.Tests/Helpers/RateLimiterTests.cs

@@ -0,0 +1,79 @@
+using System;
+using API.Helpers;
+using Xunit;
+
+namespace API.Tests.Helpers;
+
+public class RateLimiterTests
+{
+    [Fact]
+    public void AcquireTokens_Successful()
+    {
+        // Arrange
+        var limiter = new RateLimiter(3, TimeSpan.FromSeconds(1));
+
+        // Act & Assert
+        Assert.True(limiter.TryAcquire("test_key"));
+        Assert.True(limiter.TryAcquire("test_key"));
+        Assert.True(limiter.TryAcquire("test_key"));
+    }
+
+    [Fact]
+    public void AcquireTokens_ExceedLimit()
+    {
+        // Arrange
+        var limiter = new RateLimiter(2, TimeSpan.FromSeconds(10), false);
+
+        // Act
+        limiter.TryAcquire("test_key");
+        limiter.TryAcquire("test_key");
+
+        // Assert
+        Assert.False(limiter.TryAcquire("test_key"));
+    }
+
+    [Fact]
+    public void AcquireTokens_Refill()
+    {
+        // Arrange
+        var limiter = new RateLimiter(2, TimeSpan.FromSeconds(1));
+
+        // Act
+        limiter.TryAcquire("test_key");
+        limiter.TryAcquire("test_key");
+
+        // Wait for refill
+        System.Threading.Thread.Sleep(1100);
+
+        // Assert
+        Assert.True(limiter.TryAcquire("test_key"));
+    }
+
+    [Fact]
+    public void AcquireTokens_Refill_WithOff()
+    {
+        // Arrange
+        var limiter = new RateLimiter(2, TimeSpan.FromSeconds(10), false);
+
+        // Act
+        limiter.TryAcquire("test_key");
+        limiter.TryAcquire("test_key");
+
+        // Wait for refill
+        System.Threading.Thread.Sleep(2100);
+
+        // Assert
+        Assert.False(limiter.TryAcquire("test_key"));
+    }
+
+    [Fact]
+    public void AcquireTokens_MultipleKeys()
+    {
+        // Arrange
+        var limiter = new RateLimiter(2, TimeSpan.FromSeconds(1));
+
+        // Act & Assert
+        Assert.True(limiter.TryAcquire("key1"));
+        Assert.True(limiter.TryAcquire("key2"));
+    }
+}