Add class/2 for conditional checking

[sn3p]

Closes #9

[codecov-io]

Codecov Report

Merging #10 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #10   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           2      2           
  Lines          25     27    +2     
=====================================
+ Hits           25     27    +2

Impacted Files	Coverage Δ
lib/ex_css_modules/view.ex	100% <ø> (ø)	⬆️
lib/ex_css_modules/ex_css_modules.ex	100% <100%> (ø)	⬆️

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[jessedijkstra]

You're reproducing existing functionality because class_name already checks the value for truthiness.

iex(1)> ExCSSModules.class_name(
...(1)> %{ "hello" => "world" }, "hello", false)
nil
iex(2)> ExCSSModules.class_name(%{ "hello" => "world" }, "hello", false)
nil
iex(3)> ExCSSModules.class_name(%{ "hello" => "world" }, "hello", true)
"world"
iex(4)> ExCSSModules.class_name(%{ "hello" => "world", "world" => "hello" }, ["world"])
"hello"
iex(5)> ExCSSModules.class_name(%{ "hello" => "world", "world" => "hello" }, [{"world", false}])
""
iex(6)> ExCSSModules.class_name(%{ "hello" => "world", "world" => "hello" }, [{"world", false}])

Looking at these results I would do the following:
Change the class_name() function that reacts to lists to return nil instead of an empty string when no results are present, ie:

iex(5)> ExCSSModules.class_name(%{ "hello" => "world", "world" => "hello" }, [{"world", false}])
nil

And change the class attribute to return an empty string if it receives nil:

iex> class_attribute(nil)
""

This way the class function behaves the exact same way as a class_name except that it pipes to the class_attribute() function.

[jessedijkstra]

The class function duplicates behaviour which can create unwanted results if we ever change any of the behaviours.

[jessedijkstra]

Why is this appended with ....?

Should probably read returns nil if none of the conditions are met

[sn3p]

woops

[jessedijkstra]

Prefer to away from if statements as much as possible, ie:

defp join_class_name(list) when length(list) == 0, do: nil
defp join_class_name(list), do: Enum.join(list, " ")

[jessedijkstra]

This way we can just keep piping the values as well.

[sn3p]

Kinda had the same thought, do you really think this is more clear?

[jessedijkstra]

I don't know yet ;)

It is quite clear however when you read the join_class_name function what it does, gets rid of an if statement and allows you to keep piping the value to the next function which I like a lot.

[jessedijkstra]

👍