.eex template error: no function clause matching in Enum.reverse_slice/3

[kipcole9]

coveralls 0.5.5 on Erlang/OTP 19 for mix coveralls.html results in:

** (FunctionClauseError) no function clause matching in Enum.reverse_slice/3
    (elixir) lib/enum.ex:1864: Enum.reverse_slice(["cldr.ex", "lib"], 1, #Function<3.4269533/1 in ExCoveralls.Html.View.render/1>)
    lib/templates/html/htmlcov/coverage.html.eex:17: anonymous fn/2 in ExCoveralls.Html.View.render/1

The offending line is in coverage.html.eex:

<% [b | s] = String.split(file.filename, "/") |> Enum.reverse |> Enum.reverse_slice(1, &(&1.length)) %>'

Here the code is calling Enum.reverse_slice(["path", "components"], 1, &(&1.length)) which doesn't make sense to me since the third argument should be a count which should be an integer. I assume the intent is to dynamically determine the length of the list in the first argument, but this code doesn't do that.

Possible fix

Change line 17 to:

<% parts = String.split(file.filename, "/") %>
<% [b | s] = parts |> Enum.reverse |> Enum.reverse_slice(1, Enum.count(parts))%>

This appears to work (in my system).

[parroty]

Thanks for the report. Does the above fix matches your expectation? I tried to simulate the same error, but I haven't been able to yet (though your comment makes sense).
(line is tweaked for avoiding the test error with minimum change).

[kipcole9]

Confirmed the patch fixes the issue i was seeing.

[parroty]

Thanks, pushed as v0.5.6.