From 4134342765e616c5d067fc77d23db905206fd25a Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Thu, 1 Apr 2021 15:16:21 +0200
Subject: [PATCH] Print trivia for ident of ValSpfn. Fixes #1561.

---
 src/Fantomas.Tests/SignatureTests.fs | 27 +++++++++++++++++++++++++++
 src/Fantomas/AstTransformer.fs       |  3 ++-
 src/Fantomas/CodePrinter.fs          | 18 ++++++++++--------
 src/Fantomas/SourceParser.fs         |  6 ++++--
 4 files changed, 43 insertions(+), 11 deletions(-)

diff --git a/src/Fantomas.Tests/SignatureTests.fs b/src/Fantomas.Tests/SignatureTests.fs
index 725b8adc51..6626b47e4f 100644
--- a/src/Fantomas.Tests/SignatureTests.fs
+++ b/src/Fantomas.Tests/SignatureTests.fs
@@ -1298,3 +1298,30 @@ exception FileNameNotResolved of string (*description of searched locations*)  *
 
 exception LoadedSourceNotFoundIgnoring of string * range (*filename*)
 """
+
+[<Test>]
+let ``comment between attribute and val, 1561`` () =
+    formatSourceString
+        true
+        """
+namespace Baz
+
+module Bar =
+
+    [<Obsolete "">]
+    ///
+    val f : unit -> unit
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+namespace Baz
+
+module Bar =
+
+    [<Obsolete "">]
+    ///
+    val f : unit -> unit
+"""
diff --git a/src/Fantomas/AstTransformer.fs b/src/Fantomas/AstTransformer.fs
index 925b82c436..df0a024f6c 100644
--- a/src/Fantomas/AstTransformer.fs
+++ b/src/Fantomas/AstTransformer.fs
@@ -778,8 +778,9 @@ module private Ast =
 
     and visitSynValSig (svs: SynValSig) : TriviaNodeAssigner list =
         match svs with
-        | ValSpfn (attrs, _, explicitValDecls, synType, arity, _, _, _, _, expr, range) ->
+        | ValSpfn (attrs, ident, explicitValDecls, synType, arity, _, _, _, _, expr, range) ->
             [ yield mkNode ValSpfn_ range
+              yield visitIdent ident
               yield! (visitSynAttributeLists range attrs)
               yield! visitSynValTyparDecls explicitValDecls
               yield! visitSynType synType
diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
index d861424dc0..25c70f962f 100644
--- a/src/Fantomas/CodePrinter.fs
+++ b/src/Fantomas/CodePrinter.fs
@@ -862,7 +862,7 @@ and genMemberFlagsForMemberBinding astContext (mf: MemberFlags) (rangeOfBindingA
             |> Option.defaultValue (!- "override ")
         <| ctx
 
-and genVal astContext (Val (ats, px, ao, s, t, vi, isInline, _) as node) =
+and genVal astContext (Val (ats, px, ao, s, identRange, t, vi, isInline, _) as node) =
     let range, synValTyparDecls =
         match node with
         | ValSpfn (_, _, synValTyparDecls, _, _, _, _, _, _, _, range) -> range, synValTyparDecls
@@ -874,12 +874,14 @@ and genVal astContext (Val (ats, px, ao, s, t, vi, isInline, _) as node) =
 
     let (FunType namedArgs) = (t, vi)
 
-    genPreXmlDoc px +> genAttributes astContext ats
-    -- "val "
-    +> opt sepSpace ao genAccess
-    +> onlyIf isInline (!- "inline ")
-    -- s
-    +> genericParams
+    genPreXmlDoc px
+    +> genAttributes astContext ats
+    +> (!- "val "
+        +> opt sepSpace ao genAccess
+        +> onlyIf isInline (!- "inline ")
+        -- s
+        +> genericParams
+        |> genTriviaFor Ident_ identRange)
     +> sepColonWithSpacesFixed
     +> ifElse
         (List.isNotEmpty namedArgs)
@@ -3897,7 +3899,7 @@ and genMemberSig astContext node =
         | SynMemberSig.NestedType (_, r) -> r, SynMemberSig_NestedType
 
     match node with
-    | MSMember (Val (ats, px, ao, s, t, vi, isInline, ValTyparDecls (tds, _, tcs)), mf) ->
+    | MSMember (Val (ats, px, ao, s, _, t, vi, isInline, ValTyparDecls (tds, _, tcs)), mf) ->
         let (FunType namedArgs) = (t, vi)
 
         let isFunctionProperty =
diff --git a/src/Fantomas/SourceParser.fs b/src/Fantomas/SourceParser.fs
index 3a859d05eb..be67fdae60 100644
--- a/src/Fantomas/SourceParser.fs
+++ b/src/Fantomas/SourceParser.fs
@@ -1505,8 +1505,10 @@ let (|MSMember|MSInterface|MSInherit|MSValField|MSNestedType|) =
     | SynMemberSig.ValField (f, _) -> MSValField f
     | SynMemberSig.NestedType (tds, _) -> MSNestedType tds
 
-let (|Val|) (ValSpfn (ats, IdentOrKeyword (OpNameFullInPattern (s, _)), tds, t, vi, isInline, _, px, ao, _, _)) =
-    (ats, px, ao, s, t, vi, isInline, tds)
+let (|Val|)
+    (ValSpfn (ats, ((IdentOrKeyword (OpNameFullInPattern (s, _)) as ident)), tds, t, vi, isInline, _, px, ao, _, _))
+    =
+    (ats, px, ao, s, ident.idRange, t, vi, isInline, tds)
 
 // Misc