Merge pull request #126 from tfiedlerdejanze/rewrite-then-with-named-fun-reference

Rewrite then/2 when function is a named function reference

Author: novaugust

lib/style/pipes.ex

@@ -142,6 +142,8 @@ defmodule Styler.Style.Pipes do
 
   # a |> fun => a |> fun()
   defp fix_pipe({:|>, m, [lhs, {fun, m2, nil}]}), do: {:|>, m, [lhs, {fun, m2, []}]}
+  # a |> then(&fun/1) |> c => a |> fun() |> c()
+  defp fix_pipe({:|>, m, [lhs, {:then, _, [{:&, _, [{:/, _, [{fun, m2, _}, _]}]}]}]}), do: {:|>, m, [lhs, {fun, m2, []}]}
   # Credo.Check.Readability.PipeIntoAnonymousFunctions
   # rewrite anonymous function invocation to use `then/2`
   # `a |> (& &1).() |> c()` => `a |> then(& &1) |> c()`

test/style/pipes_test.exs

@@ -498,6 +498,13 @@ defmodule Styler.Style.PipesTest do
       assert_style("a |> (fn x -> x end).() |> c", "a |> then(fn x -> x end) |> c()")
     end
 
+    test "rewrites then/2 when the passed function is a named function reference" do
+      assert_style("a |> then(&fun/1) |> c", "a |> fun() |> c()")
+      assert_style("a |> then(&DateTime.from_is8601/1) |> c", "a |> DateTime.from_is8601() |> c()")
+      assert_style("a |> then(&DateTime.from_is8601/1)", "DateTime.from_is8601(a)")
+      assert_style("a |> then(&fun(&1, d)) |> c", "a |> then(&fun(&1, d)) |> c()")
+    end
+
     test "adds parens to 1-arity pipes" do
       assert_style("a |> b |> c", "a |> b() |> c()")
     end