Add space before at verbatim string in type abbreviation. Fixes fspro…

…jects#859
nojaf · Jul 9, 2020 · ed44a04 · ed44a04
1 parent 5923143
commit ed44a04
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Showing 3 changed files with 27 additions and 6 deletions.
diff --git a/src/Fantomas.Tests/TypeProviderTests.fs b/src/Fantomas.Tests/TypeProviderTests.fs
@@ -19,7 +19,7 @@ let ``should add space before type provider params``() =
 type IntegerRegex = FSharpx.Regex< @"(?<value>\d+)" >""" config
     |> prepend newline
     |> should equal """
-type IntegerRegex = FSharpx.Regex<@"(?<value>\d+)">
+type IntegerRegex = FSharpx.Regex< @"(?<value>\d+)" >
 """
 
 [<Test>]

diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
@@ -2578,14 +2578,28 @@ and genType astContext outerBracket t =
 and genAnonRecordFieldType astContext (AnonRecordFieldType(s, t)) =
     !- s +> sepColon +> (genType astContext false t)
 
-and genPrefixTypes astContext node =
+and genPrefixTypes astContext node ctx =
     match node with
-    | [] -> sepNone
+    | [] -> ctx
     // Where <  and ^ meet, we need an extra space. For example:  seq< ^a >
     | (TVar(Typar(_, true)) as t)::ts ->
-        !- "< " +> col sepComma (t::ts) (genType astContext false) -- " >"
-    | ts ->
-        !- "<" +> col sepComma ts (genType astContext false) -- ">"
+        (!- "< " +> col sepComma (t::ts) (genType astContext false) -- " >") ctx
+    | t::_ ->
+        // for example: FSharpx.Regex< @"(?<value>\d+)" >
+        let firstItemHasAtSignBeforeString =
+            match t with
+            | SourceParser.TStaticConstant(_,r) ->
+                TriviaHelpers.``has content itself that matches``
+                    (function | StringContent sc -> sc.StartsWith("@") | _ -> false)
+                    r
+                    ctx.Trivia
+            | _ -> false
+
+        (!- "<"
+        +> onlyIf firstItemHasAtSignBeforeString sepSpace
+        +> col sepComma node (genType astContext false)
+        +> onlyIf firstItemHasAtSignBeforeString sepSpace
+        -- ">") ctx
     // |> genTrivia node
 
 and genTypeList astContext node =

diff --git a/src/Fantomas/TriviaHelpers.fs b/src/Fantomas/TriviaHelpers.fs
@@ -65,6 +65,13 @@ module internal TriviaHelpers =
             | Some(CharContent c) -> Some c
             | _ -> None)
 
+    let ``has content itself that matches`` (predicate: TriviaContent -> bool) range (triviaNodes: TriviaNode list) =
+        triviaNodes
+        |> List.exists (fun tn ->
+            match tn.Range = range, tn.ContentItself with
+            | true, Some(t) -> predicate t
+            | _ -> false)
+
     let ``has content itself is ident between ticks`` range (triviaNodes: TriviaNode list) =
         triviaNodes
         |> List.choose (fun tn ->