Initial Commit

packages/api-stack/api/api-plugin-audit/tests/integration/sampling.test.ts

@@ -0,0 +1,71 @@
+import { AuditLogger, MemoryAuditAdapter } from "@suaveplan/audit-logging";
+import { describe, expect, it } from "@suaveplan/testing/runner";
+import { Hono } from "hono";
+import { createAuditMiddleware } from "../../src/middleware/audit-middleware.js";
+import type { AuditPluginConfig } from "../../src/types/types.js";
+
+const noopHostLogger = {
+    debug: () => undefined,
+    info: () => undefined,
+    warn: () => undefined,
+    error: () => undefined,
+};
+
+/**
+ * Deterministic Mulberry32 RNG so the test is reproducible across
+ * Bun + Node runtime engines.
+ */
+function mulberry32(seed: number): () => number {
+    let t = seed >>> 0;
+    return () => {
+        t = (t + 0x6d2b79f5) >>> 0;
+        let r = t;
+        r = Math.imul(r ^ (r >>> 15), r | 1);
+        r ^= r + Math.imul(r ^ (r >>> 7), r | 61);
+        return ((r ^ (r >>> 14)) >>> 0) / 4294967296;
+    };
+}
+
+describe("sampling integration", () => {
+    it("50% sample rate over 1000 requests sits in [400, 600] band", {
+        timeout: 30000,
+    }, async () => {
+        const storage = new MemoryAuditAdapter();
+        const logger = new AuditLogger({
+            storage,
+            secretKey: "x".repeat(32),
+        });
+        const config: AuditPluginConfig = {
+            sink: storage,
+            secretKey: "x".repeat(32),
+            samplingRate: 0.5,
+            excludePaths: [],
+            redactQueryParams: [],
+            redactHeaders: [],
+            redactBodyFields: [],
+            recordResponseSize: false,
+            recordRequestBody: false,
+            enableChainIntegrity: false,
+            rng: mulberry32(1234567),
+        };
+
+        const app = new Hono();
+        app.use(
+            "*",
+            createAuditMiddleware({
+                logger,
+                config,
+                hostLogger: noopHostLogger,
+            })
+        );
+        app.get("/x", (c) => c.text("ok"));
+
+        for (let i = 0; i < 1000; i += 1) {
+            await app.request(`/x?i=${i}`);
+        }
+
+        const count = storage.snapshot().length;
+        expect(count).toBeGreaterThanOrEqual(400);
+        expect(count).toBeLessThanOrEqual(600);
+    });
+});