From c95b0ba8b0b56738aaeed81e990b7e3448845a1c Mon Sep 17 00:00:00 2001
From: Matt Enlow <enlow@adobe.com>
Date: Mon, 15 Jul 2024 16:20:28 -0600
Subject: [PATCH] Rewrite `with true <- ...` to if statements. Closes #173

---
 CHANGELOG.md               |  8 +++++++-
 lib/style/blocks.ex        | 16 ++++++++++++++++
 test/style/blocks_test.exs | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 552943b..d31e73c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,9 +5,15 @@ they can and will change without that change being reflected in Styler's semanti
 
 ## main
 
+### Improvements
+
+#### `with`
+
+* remove `with` structure with no left arrows in its head to be normal code (#174)
+* `with true <- x(), do: y` => `if x(), do: y` (#173)
+
 ### Fixes
 
-* rewrite `with` with no left arrows to be normal code (#174)
 * fix `with` arrow replacement + redundant body removal creating invalid statements (#184, h/t @JesseHerrick)
 * allow Kernel unary `!` and `not` as valid pipe starts (#183, h/t @nherzing)
 
diff --git a/lib/style/blocks.ex b/lib/style/blocks.ex
index f18ace1..a6f5cff 100644
--- a/lib/style/blocks.ex
+++ b/lib/style/blocks.ex
@@ -59,6 +59,22 @@ defmodule Styler.Style.Blocks do
     run({{:case, m, [single_statement, clauses]}, zm}, ctx)
   end
 
+  # `with true <- x, do: bar` =>`if x, do: bar`
+  def run({{:with, m, [{:<-, _, [{_, _, [true]}, rhs]}, [do_kwl]]}, _} = zipper, ctx) do
+    children =
+      case rhs do
+        # `true <- foo || {:error, :shouldve_used_an_if_statement}``
+        # turn the rhs of an `||` into an else body
+        {:||, _, [head, else_body]} ->
+          [head, [do_kwl, {{:__block__, [line: m[:line] + 2], [:else]}, Style.shift_line(else_body, 3)}]]
+
+        _ ->
+          [rhs, [do_kwl]]
+      end
+
+    {:cont, Zipper.replace(zipper, {:if, m, children}), ctx}
+  end
+
   # Credo.Check.Refactor.WithClauses
   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)_/¯
diff --git a/test/style/blocks_test.exs b/test/style/blocks_test.exs
index 52a9f93..79d8ddc 100644
--- a/test/style/blocks_test.exs
+++ b/test/style/blocks_test.exs
@@ -556,6 +556,40 @@ defmodule Styler.Style.BlocksTest do
       )
     end
 
+    test "with to if" do
+      assert_style(
+        """
+        with true <- foo do
+          boop
+          bar
+        end
+        """,
+        """
+        if foo do
+          boop
+          bar
+        end
+        """
+      )
+
+      assert_style "with true <- x, do: bar", "if x, do: bar"
+
+      assert_style(
+        """
+        with true <- foo || {:error, :shouldve_used_an_if_statement} do
+          bar
+        end
+        """,
+        """
+        if foo do
+          bar
+        else
+          {:error, :shouldve_used_an_if_statement}
+        end
+        """
+      )
+    end
+
     test "switches keyword do to block do when adding postroll" do
       assert_style(
         """