alias: fix single-module alias deletion newlines bug

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 ## main
 
+## v0.10.5
+
+### Fixes
+
+* alias: fix single-module alias deletion newlines bug
+
 ## v0.10.4
 
 ### Improvements

lib/style/module_directives.ex

@@ -151,10 +151,10 @@ defmodule Styler.Style.ModuleDirectives do
     behaviours = expand_and_sort(directives[:"@behaviour"] || [])
 
     uses = (directives[:use] || []) |> Enum.flat_map(&expand_directive/1) |> reset_newlines()
-
     imports = expand_and_sort(directives[:import] || [])
-    aliases = expand_and_sort(directives[:alias] || [])
     requires = expand_and_sort(directives[:require] || [])
+    original_aliases = directives[:alias] || []
+    aliases = expand_and_sort(directives[:alias] || [])
 
     directives =
       [
@@ -170,7 +170,8 @@ defmodule Styler.Style.ModuleDirectives do
       |> fix_line_numbers(List.first(nondirectives))
 
     cond do
-      Enum.empty?(directives) ->
+      # the # of aliases can be decreased during sorting - if there were any, we need to be sure to write the deletion
+      Enum.empty?(directives) and Enum.empty?(original_aliases) ->
         parent
 
       Enum.empty?(nondirectives) ->
@@ -253,10 +254,13 @@ defmodule Styler.Style.ModuleDirectives do
     |> reset_newlines()
   end
 
-  # alias Foo.{Bar, Baz}
+  # Deletes root level aliases ala (`alias Foo` -> ``)
+  defp expand_directive({:alias, _, [{:__aliases__, _, [_]}]}), do: []
+
+  # import Foo.{Bar, Baz}
   # =>
-  # alias Foo.Bar
-  # alias Foo.Baz
+  # import Foo.Bar
+  # import Foo.Baz
   defp expand_directive({directive, _, [{{:., _, [{:__aliases__, _, module}, :{}]}, _, right}]}),
     do: Enum.map(right, fn {_, meta, segments} -> {directive, meta, [{:__aliases__, [], module ++ segments}]} end)
 

lib/style/single_node.ex

@@ -30,10 +30,6 @@ defmodule Styler.Style.SingleNode do
   alias Styler.Style
   alias Styler.Zipper
 
-  # Delete root level alias
-  # `alias Foo` -> ``
-  def run({{:alias, _, [{:__aliases__, _, [_]}]}, _} = zipper, ctx), do: {:cont, Zipper.remove(zipper), ctx}
-
   def run({node, meta}, ctx), do: {:cont, {style(node), meta}, ctx}
 
   # as of 1.15, elixir's formatter takes care of this for us.

test/style/module_directives_test.exs

@@ -415,4 +415,38 @@ defmodule Styler.Style.ModuleDirectivesTest do
       )
     end
   end
+
+  test "Deletes root level alias" do
+    assert_style("alias Foo", "")
+
+    assert_style(
+      """
+      alias unquote(Foo)
+      alias Foo
+      alias Bar, as: Bop
+      alias __MODULE__
+      """,
+      """
+      alias __MODULE__
+      alias Bar, as: Bop
+      alias unquote(Foo)
+      """
+    )
+
+    assert_style(
+      """
+      alias A.A
+      alias B.B
+      alias C
+
+      require D
+      """,
+      """
+      alias A.A
+      alias B.B
+
+      require D
+      """
+    )
+  end
 end

test/style/single_node_test.exs

@@ -293,22 +293,4 @@ defmodule Styler.Style.SingleNodeTest do
       assert_style("Enum.reverse(foo, bar) ++ bar")
     end
   end
-
-  test "Delete root level alias" do
-    assert_style("alias Foo", "")
-
-    assert_style(
-      """
-      alias unquote(Foo)
-      alias Foo
-      alias Bar, as: Bop
-      alias __MODULE__
-      """,
-      """
-      alias __MODULE__
-      alias Bar, as: Bop
-      alias unquote(Foo)
-      """
-    )
-  end
 end