Code coverage tools for Elixir?

[Fl4m3Ph03n1x]

@hauleth

Erlang do not have notation of “statement” in its’ .beam files, only lines are stored. While in theory you could use 'Abst' chunk to extract “statements” it would be infeasible due to macros (especially in Elixir), and even then there is no mapping between 'Abst' values and 'Code' segments (only 'Line' have such relation).

So unless you write EEP to introduce such connection between “statement” and 'Code' chunk then it is not possible with current VM implementation.

This is interesting. It appears that even though no .beam file is created, you are still correct !

@cover documentation

Before any analysis can take place, the involved modules must be Cover compiled . This means that some extra information is added to the module before it is compiled into a binary which then is loaded. The source file of the module is not affected and no .beam file is created.

@hauleth

It is possible, but not always feasible.

I would agree with you if only guards weren’t limited. The limitations with guards directly imply that some conditions cannot be converted into the pattern matching formula. For example, Map.key? can’t be used in a guard. if you have

if Map.key?(a), do: b, else: c

Then you are stuck.

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Interesting discussion overall, can’t wait to see where it leads!

Conclusions so far:

1. Differentiating between lines and statements makes no sense in Erlang/Elixir because BEAM doesn’t have the concept of statements. For BEAM, every line is a statement.