test : add unit tests for metricsCacheKey param serialization edge cases

package.json

@@ -8,6 +8,7 @@
     "start": "next start",
     "lint": "next lint",
     "type-check": "tsc --noEmit",
+    "test": "vitest run",
     "test:e2e": "playwright test"
   },
   "dependencies": {

test/metrics-cache.test.ts

@@ -0,0 +1,27 @@
+import { describe, it, expect } from "vitest";
+import { metricsCacheKey } from "@/lib/metrics-cache";
+
+describe("metricsCacheKey param serialization edge cases", () => {
+  it("filters out null and undefined values", () => {
+    const key = metricsCacheKey("user-1", "prs", {
+      page: null,
+      limit: undefined,
+      githubLogin: "test"
+    });
+    expect(key).toBe("metrics:user-1:prs:githubLogin=test");
+  });
+
+  it("includes numeric zero in cache key", () => {
+    const key = metricsCacheKey("user-1", "contributions", {
+      page: 0
+    });
+    expect(key).toBe("metrics:user-1:contributions:page=0");
+  });
+
+  it("serializes false boolean values", () => {
+    const key = metricsCacheKey("user-1", "repos", {
+      active: false
+    });
+    expect(key).toBe("metrics:user-1:repos:active=false");
+  });
+});

vitest.config.ts

@@ -0,0 +1,15 @@
+import { defineConfig } from "vitest/config";
+import path from "path";
+
+export default defineConfig({
+  test: {
+    include: ["test/**/*.test.ts"],
+    environment: "node",
+    globals: true,
+  },
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname, "./src"),
+    },
+  },
+});