createUnsecuredJwt makes improperly padded token

[samtstern]

[REQUIRED] Describe your environment

• Operating System version: all
• Browser version: any
• Firebase SDK version: 0.11.4 (from customer setup)
• Firebase Product: testing

[REQUIRED] Describe the problem

Steps to reproduce:

1. Create a test app

const testApp = fbtest.initializeTestApp({
  projectId: "fir-dumpster",
  auth: { uid: "alice", email: "alice@example.com" }
});

2. Use this test app with a callable function (function defined elsewhere):

const testFunctions = testApp.functions();
testFunctions.useFunctionsEmulator("http://localhost:5001")

test('we are able to call the callable function', async t => {
  const result = await testFunctions.httpsCallable("helloCallable")({});
  t.deepEqual(result.data, { hello: "world" });
});

The HTTP request will include this header:

Authorization: Bearer eyJhbGciOiJub25lIiwia2lkIjoiZmFrZWtpZCJ9.eyJ1aWQiOiJhbGljZSIsImVtYWlsIjoiYWxpY2VAZXhhbXBsZS5jb20iLCJpYXQiOjAsInN1YiI6ImFsaWNlIn0=.

If you examine that ID token you will see it should not have the =:
https://jwt.io/#debugger-io?token=eyJhbGciOiJub25lIiwia2lkIjoiZmFrZWtpZCJ9.eyJ1aWQiOiJhbGljZSIsImVtYWlsIjoiYWxpY2VAZXhhbXBsZS5jb20iLCJpYXQiOjAsInN1YiI6ImFsaWNlIn0%3D.

So if you use the node jsonwebtoken module to decode it, you get null:

> const jwt = require('jsonwebtoken')
undefined
> jwt.decode("eyJhbGciOiJub25lIiwia2lkIjoiZmFrZWtpZCJ9.eyJ1aWQiOiJhbGljZSIsImVtY
WlsIjoiYWxpY2VAZXhhbXBsZS5jb20iLCJpYXQiOjAsInN1YiI6ImFsaWNlIn0=.")
null

But if you remove the trailing = it works:

> jwt.decode("eyJhbGciOiJub25lIiwia2lkIjoiZmFrZWtpZCJ9.eyJ1aWQiOiJhbGljZSIsImVtY
WlsIjoiYWxpY2VAZXhhbXBsZS5jb20iLCJpYXQiOjAsInN1YiI6ImFsaWNlIn0.")
{ uid: 'alice', email: 'alice@example.com', iat: 0, sub: 'alice' }

Relevant Code:

See above

[hsubox76]

As far as I can tell, this code no longer exists after a large rules-unit-testing rewrite in version 2.0.0 (which was released with Firebase JS SDK version 9.0.0). If a similar issue is still a problem in the current version (10.0.0 as of now) please create a new issue.