From 503a4711761d3e2b2cac976eda9bb38decc33ea7 Mon Sep 17 00:00:00 2001
From: Florian Verdonck <florian.verdonck@outlook.com>
Date: Tue, 1 Feb 2022 08:26:28 +0100
Subject: [PATCH] Visit SynTypar indent in AstTransformer.fs. Fixes #2052.
 (#2053)

---
 src/Fantomas.Tests/CommentTests.fs   | 15 +++++++++++++++
 src/Fantomas.Tests/InterfaceTests.fs |  6 +++---
 src/Fantomas/AstTransformer.fs       |  6 +++++-
 src/Fantomas/CodePrinter.fs          | 11 ++++++-----
 src/Fantomas/SourceParser.fs         | 12 ++++++------
 5 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/src/Fantomas.Tests/CommentTests.fs b/src/Fantomas.Tests/CommentTests.fs
index 8ed6582a8a..4e1225dee7 100644
--- a/src/Fantomas.Tests/CommentTests.fs
+++ b/src/Fantomas.Tests/CommentTests.fs
@@ -1744,3 +1744,18 @@ let a = 9
 // bar
 let a = 9
 """
+
+[<Test>]
+let ``comment after SynTypar, 2052`` () =
+    formatSourceString
+        false
+        """
+let Foo<'T (* TODO *)> () = ()
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let Foo<'T (* TODO *) > () = ()
+"""
diff --git a/src/Fantomas.Tests/InterfaceTests.fs b/src/Fantomas.Tests/InterfaceTests.fs
index 8ef954e4a5..82e7fb66ac 100644
--- a/src/Fantomas.Tests/InterfaceTests.fs
+++ b/src/Fantomas.Tests/InterfaceTests.fs
@@ -236,13 +236,13 @@ type IArgParserTemplate =
 
 [<Test>]
 let ``generic interface member should have space after name`` () =
-    let source =
+    formatSourceString
+        false
         """
 type IFunc<'R> =
     abstract Invoke<'T> : unit -> 'R // without this space the code is invalid
 """
-
-    formatSourceString false source config
+        config
     |> fun formatted -> formatSourceString false formatted config
     |> should
         equal
diff --git a/src/Fantomas/AstTransformer.fs b/src/Fantomas/AstTransformer.fs
index 28ab282f62..19a2cafba7 100644
--- a/src/Fantomas/AstTransformer.fs
+++ b/src/Fantomas/AstTransformer.fs
@@ -853,7 +853,11 @@ module private Ast =
 
     and visitSynTyparDecl (std: SynTyparDecl) : TriviaNodeAssigner list =
         match std with
-        | SynTyparDecl (attrs, _) -> [ yield! (visitSynAttributeLists attrs) ]
+        | SynTyparDecl (attrs, synTypar) ->
+            [ yield! (visitSynAttributeLists attrs)
+              yield visitSynTypar synTypar ]
+
+    and visitSynTypar (SynTypar (ident, _typarStaticReq, _isCompGen)) = mkNode Ident_ ident.idRange
 
     and visitSynBindingReturnInfo (returnInfo: SynBindingReturnInfo) : TriviaNodeAssigner list =
         match returnInfo with
diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
index c120245091..2a89800e52 100644
--- a/src/Fantomas/CodePrinter.fs
+++ b/src/Fantomas/CodePrinter.fs
@@ -4260,7 +4260,9 @@ and genType astContext outerBracket t =
             +> loop t2
         | TArray (t, n) -> loop t -- " [" +> rep (n - 1) (!- ",") -- "]"
         | TAnon -> sepWild
-        | TVar tp -> genTypar astContext tp
+        | TVar (tp, r) ->
+            genTypar astContext tp
+            |> genTriviaFor SynType_Var r
         // Drop bracket around tuples before an arrow
         | TFun (TTuple ts, t) -> loopTTupleList ts +> sepArrow +> loop t
         // Do similar for tuples after an arrow
@@ -4399,7 +4401,7 @@ and genPrefixTypes astContext node (range: Range) ctx =
     match node with
     | [] -> ctx
     // Where <  and ^ meet, we need an extra space. For example:  seq< ^a >
-    | TVar (Typar (_, true)) as t :: ts ->
+    | TVar (Typar (_, _, true), _r) as t :: ts ->
         (!- "< "
          +> col sepComma (t :: ts) (genType astContext false)
          -- " >")
@@ -4491,10 +4493,9 @@ and genTypeList astContext node =
 
     expressionFitsOnRestOfLine shortExpr longExpr
 
-and genTypar astContext (Typar (s, isHead) as node) =
+and genTypar astContext (Typar (s, idRange, isHead)) =
     ifElse isHead (ifElse astContext.IsFirstTypeParam (!- " ^") (!- "^")) (!- "'")
-    -- s
-    |> genTriviaFor SynType_Var node.Range
+    +> genTriviaFor Ident_ idRange !-s
 
 and genTypeConstraint astContext node =
     match node with
diff --git a/src/Fantomas/SourceParser.fs b/src/Fantomas/SourceParser.fs
index 9bcdb87175..5a649414f0 100644
--- a/src/Fantomas/SourceParser.fs
+++ b/src/Fantomas/SourceParser.fs
@@ -181,10 +181,10 @@ let (|OpNameFull|) (x: Identifier) =
 
 // Type params
 
-let inline (|Typar|) (SynTypar.SynTypar (Ident s, req, _)) =
+let inline (|Typar|) (SynTypar.SynTypar (Ident s as ident, req, _)) =
     match req with
-    | TyparStaticReq.None -> (s, false)
-    | TyparStaticReq.HeadType -> (s, true)
+    | TyparStaticReq.None -> (s, ident.idRange, false)
+    | TyparStaticReq.HeadType -> (s, ident.idRange, true)
 
 let inline (|ValTyparDecls|) (SynValTyparDecls (tds, b)) = (tds, b)
 
@@ -199,7 +199,7 @@ let rec (|RationalConst|) =
 let (|Measure|) x =
     let rec loop =
         function
-        | SynMeasure.Var (Typar (s, _), _) -> s
+        | SynMeasure.Var (Typar (s, _, _), _) -> s
         | SynMeasure.Anon _ -> "_"
         | SynMeasure.One -> "1"
         | SynMeasure.Product (m1, m2, _) ->
@@ -1446,7 +1446,7 @@ let (|TAnon|_|) =
 
 let (|TVar|_|) =
     function
-    | SynType.Var (tp, _) -> Some tp
+    | SynType.Var (tp, r) -> Some(tp, r)
     | _ -> None
 
 let (|TFun|_|) =
@@ -1648,7 +1648,7 @@ let rec (|UppercaseSynType|LowercaseSynType|) (synType: SynType) =
 
     match synType with
     | SynType.LongIdent (LongIdentWithDots lid) -> lid.Split('.') |> Seq.last |> upperOrLower
-    | SynType.Var (Typar (s, _), _) -> upperOrLower s
+    | SynType.Var (Typar (s, _, _), _) -> upperOrLower s
     | SynType.App (st, _, _, _, _, _, _) -> (|UppercaseSynType|LowercaseSynType|) st
     | _ -> failwithf "cannot determine if synType %A is uppercase or lowercase" synType