From fefa883096b4ad0f2da0d4dd4c358d55c24cb854 Mon Sep 17 00:00:00 2001
From: Alexander Esgen <alexander.esgen@tweag.io>
Date: Tue, 26 Nov 2024 21:31:03 +0100
Subject: [PATCH] Correctly format non-promoted type-level tuples

This can only occur with `NoListTuplePuns`.

Closes #1146
---
 CHANGELOG.md                                         |  3 +++
 .../declaration/type/promotion-no-puns-out.hs        |  5 +++++
 data/examples/declaration/type/promotion-no-puns.hs  |  5 +++++
 src/Ormolu/Printer/Meat/Type.hs                      | 12 ++++++++----
 4 files changed, 21 insertions(+), 4 deletions(-)
 create mode 100644 data/examples/declaration/type/promotion-no-puns-out.hs
 create mode 100644 data/examples/declaration/type/promotion-no-puns.hs

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 79aaa392b..783e96306 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,9 @@
    * GHC proposal [#281](https://github.com/ghc-proposals/ghc-proposals/blob/c9401f037cb22d1661931b2ec621925101052997/proposals/0281-visible-forall.rst): accept more types in terms: `forall` quantifications, constraint arrows `=>`, type arrows `->` (enabled by default)
    * Part of GHC proposal [#425](https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0425-decl-invis-binders.rst): wildcard binders (enabled by default)
 
+* Correctly format non-promoted type-level tuples with `NoListTuplePuns`. [Issue
+  1146](https://github.com/tweag/ormolu/issues/1146).
+
 ## Ormolu 0.7.7.0
 
 * Use single-line layout for parens around single-line content. [Issue
diff --git a/data/examples/declaration/type/promotion-no-puns-out.hs b/data/examples/declaration/type/promotion-no-puns-out.hs
new file mode 100644
index 000000000..8579e5389
--- /dev/null
+++ b/data/examples/declaration/type/promotion-no-puns-out.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE NoListTuplePuns #-}
+
+type X = (Int, String)
+
+type Y = [String, Int]
diff --git a/data/examples/declaration/type/promotion-no-puns.hs b/data/examples/declaration/type/promotion-no-puns.hs
new file mode 100644
index 000000000..16574ebbb
--- /dev/null
+++ b/data/examples/declaration/type/promotion-no-puns.hs
@@ -0,0 +1,5 @@
+{-# Language NoListTuplePuns #-}
+
+type X = (Int, String)
+
+type Y = [String, Int]
diff --git a/src/Ormolu/Printer/Meat/Type.hs b/src/Ormolu/Printer/Meat/Type.hs
index 770a0e596..622ec431f 100644
--- a/src/Ormolu/Printer/Meat/Type.hs
+++ b/src/Ormolu/Printer/Meat/Type.hs
@@ -156,11 +156,15 @@ p_hsType' multilineArgs = \case
         (IsPromoted, L _ t : _) | startsWithSingleQuote t -> space
         _ -> return ()
       sep commaDel (sitcc . located' p_hsType) xs
-  HsExplicitTupleTy _ _p xs -> do
-    txt "'"
+  HsExplicitTupleTy _ p xs -> do
+    case p of
+      IsPromoted -> txt "'"
+      NotPromoted -> return ()
     parens N $ do
-      case xs of
-        L _ t : _ | startsWithSingleQuote t -> space
+      -- If this tuple is promoted and the first element starts with a single
+      -- quote, we need to put a space in between or it fails to parse.
+      case (p, xs) of
+        (IsPromoted, L _ t : _) | startsWithSingleQuote t -> space
         _ -> return ()
       sep commaDel (located' p_hsType) xs
   HsTyLit _ t ->