fix with rewrites when keyword with an else stab (#220)

Closes #219

fixes for both <1.17 and >=1.17

Author: novaugust

CHANGELOG.md

@@ -9,7 +9,8 @@ they can and will change without that change being reflected in Styler's semanti
 
 #### Ex1.17+
 
-Replace `:timer.units(x)` with the new `to_timeout(unit: x)` for `hours|minutes|seconds`
+- Replace `:timer.units(x)` with the new `to_timeout(unit: x)` for `hours|minutes|seconds`
+- Handle `, else: (_ -> x)` bugs introduced by `(_ -> x)` being termed a literal (#219, h/t @iamhassangm)
 
 #### Ex1.18+
 
@@ -48,6 +49,7 @@ This release taught Styler to try just that little bit harder when doing alias l
 ### Fixes
 
 - `pipes`: handle pipifying when the first arg is itself a pipe: `c(a |> b, d)` => `a |> b() |> c(d)` (#214, h/t @kybishop)
+- `with`: correctly handle a stabby `with` `, else: (_ -> :ok)` being rewritten to a case (#219, h/t @iamhassangm)
 
 ## 1.3.3
 

lib/style/blocks.ex

@@ -53,10 +53,31 @@ defmodule Styler.Style.Blocks do
   # to `case single_statement do success -> body; ...elses end`
   def run({{:with, m, [{:<-, am, [success, single_statement]}, [body, elses]]}, zm}, ctx) do
     {{:__block__, do_meta, [:do]}, body} = body
-    {{:__block__, _else_meta, [:else]}, elses} = elses
+    {{:__block__, _, [:else]}, elses} = elses
+
+    elses =
+      case elses do
+        # unwrap a stab ala `, else: (_ -> :ok)`. these became literals in 1.17
+        {:__block__, _, [[{:->, _, _}] = stab]} -> stab
+        elses -> elses
+      end
+
+    # drops keyword formatting etc
+    do_meta = [line: do_meta[:line]]
     clauses = [{{:__block__, am, [:do]}, [{:->, do_meta, [[success], body]} | elses]}]
+    end_line = Style.max_line(elses) + 1
+
+    # fun fact: i added the detailed meta just because i noticed it was missing while debugging something ...
+    # ... and it fixed the bug 🤷
+    case_meta = [
+      end_of_expression: [newlines: 1, line: end_line],
+      do: do_meta,
+      end: [line: end_line],
+      line: m[:line]
+    ]
+
     # recurse in case this new case should be rewritten to a `if`, etc
-    run({{:case, m, [single_statement, clauses]}, zm}, ctx)
+    run({{:case, case_meta, [single_statement, clauses]}, zm}, ctx)
   end
 
   # `with true <- x, do: bar` =>`if x, do: bar`

test/style/blocks_test.exs

@@ -239,7 +239,7 @@ defmodule Styler.Style.BlocksTest do
     end
   end
 
-  describe "with statements" do
+  describe "with" do
     test "replacement due to no (or all removed) arrows" do
       assert_style(
         """
@@ -787,6 +787,20 @@ defmodule Styler.Style.BlocksTest do
       end
       """
     end
+
+    test "elixir1.17+ stab regressions" do
+      assert_style(
+        """
+        with :ok <- foo, do: :bar, else: (_ -> :baz)
+        """,
+        """
+        case foo do
+          :ok -> :bar
+          _ -> :baz
+        end
+        """
+      )
+    end
   end
 
   test "Credo.Check.Refactor.CondStatements" do