Handle module_function with no arguments

[vinistock]

Motivation

Closes #2653

This PR handles the other missing part of module_function, which is when it gets invoked with no argument. After looking into the Ruby source code, it seems that module_func is a flag considered as part of the visibility scope.

Invoking module_function will both:

1. Start marking new methods as singleton methods
2. Push private into the stack

Implementation

I created a new VisibilityScope object to help us encapsulate all aspects of visibility, so that we don't forget to handle module_func where necessary.

Then I started handling the case of module_function with no arguments, which essentially pushes a new scope into the stack with module_func: true and visibility private.

Automated Tests

Added a few tests.

[vinistock]

• Handle module_function with no arguments #3018 👈 (View in Graphite)
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[vinistock]

Merge activity

• Jan 7, 2:31 PM EST: A user merged this pull request with Graphite.