From 47fefda4d545132d8d28fbf4e0a62ff53e6c5262 Mon Sep 17 00:00:00 2001
From: Giulio Vaccari <io@giuliovaccari.it>
Date: Sat, 11 Apr 2026 15:22:00 +0200
Subject: [PATCH] test(fingerprint): add unit tests for fingerprint generation
 and session helpers

Co-Authored-By: Giulio Vaccari <io@giuliovaccari.it>
---
 src/plugin/fingerprint.test.ts | 170 +++++++++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)
 create mode 100644 src/plugin/fingerprint.test.ts

diff --git a/src/plugin/fingerprint.test.ts b/src/plugin/fingerprint.test.ts
new file mode 100644
index 0000000..d30869b
--- /dev/null
+++ b/src/plugin/fingerprint.test.ts
@@ -0,0 +1,170 @@
+import { describe, expect, it, vi, beforeEach } from "vitest";
+import {
+  generateFingerprint,
+  collectCurrentFingerprint,
+  updateFingerprintVersion,
+  buildFingerprintHeaders,
+  getSessionFingerprint,
+  regenerateSessionFingerprint,
+  type Fingerprint,
+} from "./fingerprint";
+
+// ─── generateFingerprint ──────────────────────────────────────────────────────
+
+describe("generateFingerprint", () => {
+  it("returns an object with all required Fingerprint fields", () => {
+    const fp = generateFingerprint();
+    expect(fp).toHaveProperty("deviceId");
+    expect(fp).toHaveProperty("sessionToken");
+    expect(fp).toHaveProperty("userAgent");
+    expect(fp).toHaveProperty("apiClient");
+    expect(fp).toHaveProperty("clientMetadata");
+    expect(fp).toHaveProperty("createdAt");
+  });
+
+  it("deviceId is a valid UUID", () => {
+    const fp = generateFingerprint();
+    expect(fp.deviceId).toMatch(
+      /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i,
+    );
+  });
+
+  it("sessionToken is a hex string of 32 chars", () => {
+    const fp = generateFingerprint();
+    expect(fp.sessionToken).toMatch(/^[0-9a-f]{32}$/);
+  });
+
+  it("clientMetadata.pluginType is GEMINI", () => {
+    const fp = generateFingerprint();
+    expect(fp.clientMetadata.pluginType).toBe("GEMINI");
+  });
+
+  it("clientMetadata.platform is WINDOWS or MACOS", () => {
+    const fp = generateFingerprint();
+    expect(["WINDOWS", "MACOS"]).toContain(fp.clientMetadata.platform);
+  });
+
+  it("clientMetadata.ideType is ANTIGRAVITY", () => {
+    const fp = generateFingerprint();
+    expect(fp.clientMetadata.ideType).toBe("ANTIGRAVITY");
+  });
+
+  it("userAgent contains antigravity/ prefix", () => {
+    const fp = generateFingerprint();
+    expect(fp.userAgent).toMatch(/^antigravity\//);
+  });
+
+  it("createdAt is a recent timestamp", () => {
+    const before = Date.now();
+    const fp = generateFingerprint();
+    const after = Date.now();
+    expect(fp.createdAt).toBeGreaterThanOrEqual(before);
+    expect(fp.createdAt).toBeLessThanOrEqual(after);
+  });
+
+  it("each call produces a different deviceId", () => {
+    const ids = new Set(Array.from({ length: 10 }, () => generateFingerprint().deviceId));
+    expect(ids.size).toBe(10);
+  });
+});
+
+// ─── collectCurrentFingerprint ────────────────────────────────────────────────
+
+describe("collectCurrentFingerprint", () => {
+  it("returns a valid Fingerprint shape", () => {
+    const fp = collectCurrentFingerprint();
+    expect(fp.deviceId).toBeTruthy();
+    expect(fp.sessionToken).toBeTruthy();
+    expect(fp.userAgent).toBeTruthy();
+    expect(fp.clientMetadata.pluginType).toBe("GEMINI");
+  });
+
+  it("ideType is always ANTIGRAVITY", () => {
+    const fp = collectCurrentFingerprint();
+    expect(fp.clientMetadata.ideType).toBe("ANTIGRAVITY");
+  });
+
+  it("platform is WINDOWS or MACOS", () => {
+    const fp = collectCurrentFingerprint();
+    expect(["WINDOWS", "MACOS"]).toContain(fp.clientMetadata.platform);
+  });
+});
+
+// ─── updateFingerprintVersion ─────────────────────────────────────────────────
+
+describe("updateFingerprintVersion", () => {
+  function makeFp(userAgent: string): Fingerprint {
+    return {
+      deviceId: "d",
+      sessionToken: "s",
+      userAgent,
+      apiClient: "a",
+      clientMetadata: { ideType: "ANTIGRAVITY", platform: "MACOS", pluginType: "GEMINI" },
+      createdAt: Date.now(),
+    };
+  }
+
+  it("returns false when version matches current", () => {
+    const fp = makeFp("antigravity/1.18.3 darwin/arm64");
+    // We don't know current version, but if already correct it returns false
+    const result = updateFingerprintVersion(fp);
+    // Either false (same) or true (updated) — just verify no throw
+    expect(typeof result).toBe("boolean");
+  });
+
+  it("updates userAgent when version differs and returns true", () => {
+    const fp = makeFp("antigravity/0.0.1 darwin/arm64");
+    const updated = updateFingerprintVersion(fp);
+    expect(updated).toBe(true);
+    expect(fp.userAgent).not.toContain("0.0.1");
+    expect(fp.userAgent).toMatch(/^antigravity\//);
+  });
+
+  it("preserves everything after the version in userAgent", () => {
+    const fp = makeFp("antigravity/0.0.1 darwin/arm64");
+    updateFingerprintVersion(fp);
+    expect(fp.userAgent).toContain("darwin/arm64");
+  });
+
+  it("does not modify userAgent when it has no version prefix", () => {
+    const fp = makeFp("some-other-agent/1.0");
+    const updated = updateFingerprintVersion(fp);
+    expect(updated).toBe(false);
+    expect(fp.userAgent).toBe("some-other-agent/1.0");
+  });
+});
+
+// ─── buildFingerprintHeaders ──────────────────────────────────────────────────
+
+describe("buildFingerprintHeaders", () => {
+  it("returns empty object for null fingerprint", () => {
+    expect(buildFingerprintHeaders(null)).toEqual({});
+  });
+
+  it("returns User-Agent header from fingerprint", () => {
+    const fp = generateFingerprint();
+    const headers = buildFingerprintHeaders(fp);
+    expect(headers["User-Agent"]).toBe(fp.userAgent);
+  });
+});
+
+// ─── session fingerprint ──────────────────────────────────────────────────────
+
+describe("getSessionFingerprint / regenerateSessionFingerprint", () => {
+  it("getSessionFingerprint returns the same object on repeated calls", () => {
+    const a = getSessionFingerprint();
+    const b = getSessionFingerprint();
+    expect(a).toBe(b);
+  });
+
+  it("regenerateSessionFingerprint returns a new object", () => {
+    const before = getSessionFingerprint();
+    const next = regenerateSessionFingerprint();
+    expect(next).not.toBe(before);
+  });
+
+  it("after regeneration, getSessionFingerprint returns the new fingerprint", () => {
+    const next = regenerateSessionFingerprint();
+    expect(getSessionFingerprint()).toBe(next);
+  });
+});