Debugging tip! One quick way to find out which functions you're executing.

When running tests, we sometimes want to know which functions are being executed.

You could write custom dbg/1 statements in each of the functions:

def function_a do
  dbg(:function_a)
end

def function_b do
  dbg(:function_b)
end

...

def function_z do
  dbg(:function_z)
end

But that’s kind of a pain. It would be nicer if we could just call dbg/1 with the current function’s name – without us having to know the name.

How can we print the name of the function without having to know it?”

Well, it turns out there’s a nice macro helper just for that! 🥳

Use the ENV macro

The __ENV__ macro has a ton of information about the current environment. One of the things you can get is the current function.

So, you can call the function/0 function on it to get the current function being executed!

def function_a do
  dbg(__ENV__.function)
end

def function_b do
  dbg(__ENV__.function)
end

...

def function_z do
  dbg(__ENV__.function)
end

Pretty neat, huh?

Docs: https://hexdocs.pm/elixir/main/Kernel.SpecialForms.html#ENV/0