From 423180427464746458b7ed50a9f9c6c1439b408e Mon Sep 17 00:00:00 2001
From: Sandy Maguire <sandy@sandymaguire.me>
Date: Fri, 18 Feb 2022 00:26:28 -0800
Subject: [PATCH] Don't use keywords for variable names

---
 .../hls-tactics-plugin/src/Wingman/Naming.hs  | 24 ++++++++++++++++++-
 .../test/CodeAction/DestructSpec.hs           |  1 +
 .../test/golden/DestructInt.expected.hs       |  7 ++++++
 .../test/golden/DestructInt.hs                |  7 ++++++
 4 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 plugins/hls-tactics-plugin/test/golden/DestructInt.expected.hs
 create mode 100644 plugins/hls-tactics-plugin/test/golden/DestructInt.hs

diff --git a/plugins/hls-tactics-plugin/src/Wingman/Naming.hs b/plugins/hls-tactics-plugin/src/Wingman/Naming.hs
index ab0c0e23d9..832fa117e1 100644
--- a/plugins/hls-tactics-plugin/src/Wingman/Naming.hs
+++ b/plugins/hls-tactics-plugin/src/Wingman/Naming.hs
@@ -220,7 +220,29 @@ mkGoodName in_scope (mkTyName -> tn)
   . foldMap (\n -> bool (pure n) mempty $ check n)
   $ tn <> fmap (<> "'") tn
   where
-    check n = S.member (mkVarOcc n) in_scope
+    check n = S.member (mkVarOcc n) $ illegalNames <> in_scope
+
+
+illegalNames :: Set OccName
+illegalNames = S.fromList $ fmap mkVarOcc
+  [ "case"
+  , "of"
+  , "class"
+  , "data"
+  , "do"
+  , "type"
+  , "if"
+  , "then"
+  , "else"
+  , "let"
+  , "in"
+  , "mdo"
+  , "newtype"
+  , "proc"
+  , "rec"
+  , "where"
+  ]
+
 
 
 ------------------------------------------------------------------------------
diff --git a/plugins/hls-tactics-plugin/test/CodeAction/DestructSpec.hs b/plugins/hls-tactics-plugin/test/CodeAction/DestructSpec.hs
index d0f76db01c..2251abfeb2 100644
--- a/plugins/hls-tactics-plugin/test/CodeAction/DestructSpec.hs
+++ b/plugins/hls-tactics-plugin/test/CodeAction/DestructSpec.hs
@@ -20,6 +20,7 @@ spec = do
     destructTest "b"     7 10 "DestructTyFam"
     destructTest "b"     7 10 "DestructDataFam"
     destructTest "b"    17 10 "DestructTyToDataFam"
+    destructTest "t"     6 10 "DestructInt"
 
   describe "layout" $ do
     destructTest "b"  4  3 "LayoutBind"
diff --git a/plugins/hls-tactics-plugin/test/golden/DestructInt.expected.hs b/plugins/hls-tactics-plugin/test/golden/DestructInt.expected.hs
new file mode 100644
index 0000000000..0f14deef83
--- /dev/null
+++ b/plugins/hls-tactics-plugin/test/golden/DestructInt.expected.hs
@@ -0,0 +1,7 @@
+import Data.Int
+
+data Test = Test Int32
+
+test :: Test -> Int32
+test (Test in') = _w0
+
diff --git a/plugins/hls-tactics-plugin/test/golden/DestructInt.hs b/plugins/hls-tactics-plugin/test/golden/DestructInt.hs
new file mode 100644
index 0000000000..432a6d4074
--- /dev/null
+++ b/plugins/hls-tactics-plugin/test/golden/DestructInt.hs
@@ -0,0 +1,7 @@
+import Data.Int
+
+data Test = Test Int32
+
+test :: Test -> Int32
+test t = _
+