initial spike

lib/style.ex

@@ -83,6 +83,9 @@ defmodule Styler.Style do
     end
   end
 
+  def do_block?([{{:__block__, _, [:do]}, _body} | _]), do: true
+  def do_block?(_), do: false
+
   @doc """
   Returns a zipper focused on the nearest node where additional nodes can be inserted (a "block").
 

lib/style/blocks.ex

@@ -79,9 +79,8 @@ defmodule Styler.Style.Blocks do
   def run({{:with, with_meta, children}, _} = zipper, ctx) when is_list(children) do
     # a std lib `with` block will have at least one left arrow and a `do` body. anything else we skip ¯\_(ツ)_/¯
     arrow_or_match? = &(left_arrow?(&1) || match?({:=, _, _}, &1))
-    do_block? = &match?([{{:__block__, _, [:do]}, _body} | _], &1)
 
-    if Enum.any?(children, arrow_or_match?) and Enum.any?(children, do_block?) do
+    if Enum.any?(children, arrow_or_match?) and Enum.any?(children, &Style.do_block?/1) do
       {preroll, children} =
         children
         |> Enum.map(fn

lib/style/pipes.ex

@@ -130,6 +130,16 @@ defmodule Styler.Style.Pipes do
     end
   end
 
+  # a(b |> c[, ...args])
+  # maybe pipeify it
+  def run({{f, m, [{:|>, _, _} = pipe | args]}, _} = zipper, ctx) do
+    if Enum.any?(args, &Style.do_block?/1) do
+      {:cont, zipper, ctx}
+    else
+      {:cont, Zipper.replace(zipper, {:|>, m, [pipe, {f, m, args}]}), ctx}
+    end
+  end
+
   def run(zipper, ctx), do: {:cont, zipper, ctx}
 
   defp fix_pipe_start({pipe, zmeta} = zipper) do

test/style/pipes_test.exs

@@ -767,8 +767,8 @@ defmodule Styler.Style.PipesTest do
     end
   end
 
-  describe "comments" do
-    test "unpiping doesn't move comment in anonymous function" do
+  describe "comments and..." do
+    test "unpiping" do
       assert_style(
         """
         aliased =
@@ -850,10 +850,9 @@ defmodule Styler.Style.PipesTest do
         """
       )
     end
-  end
 
-  test "optimizing with comments" do
-    assert_style(
+    test "optimizing" do
+      assert_style(
       """
       a
       |> Enum.map(fn b ->
@@ -873,9 +872,9 @@ defmodule Styler.Style.PipesTest do
       end)
       |> Enum.each(...)
       """
-    )
+      )
 
-    assert_style(
+      assert_style(
       """
       a
       |> Enum.map(fn b ->
@@ -895,9 +894,9 @@ defmodule Styler.Style.PipesTest do
       end)
       |> Enum.each(...)
       """
-    )
+      )
 
-    assert_style(
+      assert_style(
       """
       a
       |> Enum.map(fn b ->
@@ -917,6 +916,20 @@ defmodule Styler.Style.PipesTest do
       end)
       |> Enum.each(...)
       """
-    )
+      )
+    end
+  end
+
+  describe "pipifying" do
+    test "no false positives" do
+      pipe = "a() |> b() |> c()"
+      assert_style "fn -> #{pipe} end"
+      assert_style "if #{pipe}, do: ..."
+      assert_style "x\n\n#{pipe}"
+    end
+
+    test "pipifying" do
+      assert_style "d(a |> b |> c)", "a |> b() |> c() |> d()"
+    end
   end
 end