fix(utils): Support crypto.getRandomValues in old Chromium versions (#9251)

Here is my proposal to fix `getRandomByte` function throwing an error
due to `crypto.getRandomValues` returning `undefined` in old browser
engines like Chromium 23.

This error could be fixed as well by using a polyfill in every project
that imports and uses Sentry but, since the change of this PR only
involved keeping the `Uint8Array` reference in a variable, I thought it
would be worth it to give it a try.

Author: jghinestrosa

packages/utils/src/misc.ts

@@ -31,7 +31,15 @@ export function uuid4(): string {
       return crypto.randomUUID().replace(/-/g, '');
     }
     if (crypto && crypto.getRandomValues) {
-      getRandomByte = () => crypto.getRandomValues(new Uint8Array(1))[0];
+      getRandomByte = () => {
+        // crypto.getRandomValues might return undefined instead of the typed array
+        // in old Chromium versions (e.g. 23.0.1235.0 (151422))
+        // However, `typedArray` is still filled in-place.
+        // @see https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues#typedarray
+        const typedArray = new Uint8Array(1);
+        crypto.getRandomValues(typedArray);
+        return typedArray[0];
+      };
     }
   } catch (_) {
     // some runtimes can crash invoking crypto

packages/utils/test/misc.test.ts

@@ -343,6 +343,25 @@ describe('uuid4 generation', () => {
       expect(uuid4()).toMatch(uuid4Regex);
     }
   });
+
+  // Corner case related to crypto.getRandomValues being only
+  // semi-implemented (e.g. Chromium 23.0.1235.0 (151422))
+  it('returns valid uuid v4 even if crypto.getRandomValues does not return a typed array', () => {
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    const cryptoMod = require('crypto');
+
+    const getRandomValues = (typedArray: Uint8Array) => {
+      if (cryptoMod.getRandomValues) {
+        cryptoMod.getRandomValues(typedArray);
+      }
+    };
+
+    (global as any).crypto = { getRandomValues };
+
+    for (let index = 0; index < 1_000; index++) {
+      expect(uuid4()).toMatch(uuid4Regex);
+    }
+  });
 });
 
 describe('arrayify()', () => {