Problematic comparison in store : observe() : subscribe()

[UnsungHero97]

Auth0 Lock v10.20.0

I'm using an undocumented API method, lock.destroy(), and I encountered issue #907. After tracing the code, I think I've found a problematic comparison that leads to that issue:

lock/src/store/index.js

Lines 8 to 10 in 7f0e0b5

	const m = getEntity(newState, 'lock', id);
	const oldM = getEntity(oldState, 'lock', id);
	if (m != oldM) f(m);

Once destroy() is invoked, getEntity() returns undefined for both m and oldM, which means f(m) will be invoked with m being undefined, which then causes Uncaught TypeError: Cannot read property 'getIn' of undefined in #907.

Shouldn't this check instead be:

if (m && oldM && m != oldM) f(m);

...? Furthermore, since both m and oldM are both immutable-js Maps, shouldn't m != oldM instead be !m.equals(oldM)?

[luisrudge]

🎉 Thanks. Would you mind sending a PR to fix this?

[UnsungHero97]

@luisrudge, here you go!

#1091

[luisrudge]

fixed in #1653