Minecraft Version

1.20.1

Version

1.109.6

Details

The documentation says that the ReadHandle.readAll (docs) returns nil when the cursor is at the end of the file.
In fact, in this case, the method returns an empty string.
So

handler.readAll()
print(type(handler.readAll()))

Prints string, when it should print nil

So there's probably a mistake in the documentation or a bug.

ReadWriteHandle.readAll seems to be affected too

Thanks for the report! I have corrected the docs in 34a2fd0.

Binary handles (rb) used to return nil if they reached the end of the file, while text handles (r) returned an empty string. As of the unification of file handles in CC:T 1.109, both will always return an empty string. This matches the behaviour of PUC Lua, and I think generally is less confusing.