From 3a907af08bb8c338c00f48c3032f15c82ed297bf Mon Sep 17 00:00:00 2001
From: mstrasinskis <98811342+mstrasinskis@users.noreply.github.com>
Date: Fri, 3 Jun 2022 10:17:33 +0200
Subject: [PATCH] fix: add setBigUint64 polyfill (#577)

* fix: add setBigUint64 polyfill

* test: makeNonce setBigUint64 polyfill

* test: update makeNonce polyfill test (should create same value)
---
 packages/agent/src/agent/http/http.test.ts | 48 +++++++++++++++++++---
 packages/agent/src/agent/http/types.ts     |  9 +++-
 2 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/packages/agent/src/agent/http/http.test.ts b/packages/agent/src/agent/http/http.test.ts
index e68ddfd43..21cf8d002 100644
--- a/packages/agent/src/agent/http/http.test.ts
+++ b/packages/agent/src/agent/http/http.test.ts
@@ -362,10 +362,46 @@ describe('replace identity', () => {
     expect(mockFetch).toBeCalledTimes(1);
   });
 });
-describe('makeNonce should create unique values', () => {
-  const nonces = new Set();
-  for (let i = 0; i < 100; i++) {
-    nonces.add(toHexString(makeNonce()));
-  }
-  expect(nonces.size).toBe(100);
+
+describe('makeNonce', () => {
+  it('should create unique values', () => {
+    const nonces = new Set();
+    for (let i = 0; i < 100; i++) {
+      nonces.add(toHexString(makeNonce()));
+    }
+    expect(nonces.size).toBe(100);
+  });
+
+  describe('setBigUint64 polyfill', () => {
+    const DataViewConstructor = DataView;
+    let spyOnSetUint32: jest.SpyInstance;
+    let usePolyfill = false;
+
+    beforeAll(() => {
+      jest.spyOn(Math, 'random').mockImplementation(() => 0.5);
+      jest.spyOn(globalThis, 'DataView').mockImplementation(buffer => {
+        const view: DataView = new DataViewConstructor(buffer);
+        view.setBigUint64 = usePolyfill ? undefined : view.setBigUint64;
+        spyOnSetUint32 = jest.spyOn(view, 'setUint32');
+        return view;
+      });
+    });
+
+    afterAll(() => {
+      jest.clearAllMocks();
+      jest.restoreAllMocks();
+    });
+
+    it('should create same value using polyfill', () => {
+      const originalNonce = toHexString(makeNonce());
+      expect(spyOnSetUint32).toBeCalledTimes(2);
+
+      usePolyfill = true;
+
+      const nonce = toHexString(makeNonce());
+      expect(spyOnSetUint32).toBeCalledTimes(4);
+
+      expect(nonce).toBe(originalNonce);
+    });
+  });
 });
diff --git a/packages/agent/src/agent/http/types.ts b/packages/agent/src/agent/http/types.ts
index ff8e3da92..e0dcfc489 100644
--- a/packages/agent/src/agent/http/types.ts
+++ b/packages/agent/src/agent/http/types.ts
@@ -110,7 +110,14 @@ export function makeNonce(): Nonce {
   const now = BigInt(+Date.now());
   const randHi = Math.floor(Math.random() * 0xffffffff);
   const randLo = Math.floor(Math.random() * 0xffffffff);
-  view.setBigUint64(0, now);
+  // Fix for IOS < 14.8 setBigUint64 absence
+  if (typeof view.setBigUint64 === 'function') {
+    view.setBigUint64(0, now);
+  } else {
+    const TWO_TO_THE_32 = BigInt(1) << BigInt(32);
+    view.setUint32(0, Number(now >> BigInt(32)));
+    view.setUint32(4, Number(now % TWO_TO_THE_32));
+  }
   view.setUint32(8, randHi);
   view.setUint32(12, randLo);