Added multiline upcast/downcast formatting.

src/Fantomas.Tests/CastTests.fs

@@ -0,0 +1,53 @@
+module Fantomas.Tests.CastTests
+
+open NUnit.Framework
+open FsUnit
+open Fantomas.Tests.TestHelper
+
+[<Test>]
+let ``multiline downcast expression, `` () =
+    formatSourceString false """
+longMethodName
+    longArgument
+    longArgument2
+:?> List<bool>
+"""
+        { config with
+              MaxLineLength = 30
+              SpaceBeforeUppercaseInvocation = true
+              SpaceBeforeColon = true
+              SpaceBeforeSemicolon = true
+              AlignFunctionSignatureToIndentation = true
+              AlternativeLongMemberDefinitions = true
+              DisableElmishSyntax = true }
+    |> prepend newline
+    |> should equal """
+longMethodName
+    longArgument
+    longArgument2
+:?> List<bool>
+"""
+
+[<Test>]
+let ``multiline upcast expression, `` () =
+    formatSourceString false """
+longMethodName
+    longArgument
+    longArgument2
+:> List<bool>
+"""
+        { config with
+              MaxLineLength = 30
+              SpaceBeforeUppercaseInvocation = true
+              SpaceBeforeColon = true
+              SpaceBeforeSemicolon = true
+              AlignFunctionSignatureToIndentation = true
+              AlternativeLongMemberDefinitions = true
+              DisableElmishSyntax = true }
+    |> prepend newline
+    |> should equal """
+longMethodName
+    longArgument
+    longArgument2
+:> List<bool>
+"""

src/Fantomas.Tests/ComputationExpressionTests.fs

@@ -1519,7 +1519,8 @@ let sendPushNotifications =
                                     subscriptions
                                     s.Origin
                                     s.Endpoint
-                    } :> Task)
+                    }
+                    :> Task)
             |> Task.WhenAll)
 """
 

src/Fantomas.Tests/Fantomas.Tests.fsproj

@@ -79,6 +79,7 @@
     <Compile Include="NumberOfItemsMultilineInfixOperatorExpressionTests.fs" />
     <Compile Include="SynExprNewTests.fs" />
     <Compile Include="DisableElmishTests.fs" />
+    <Compile Include="CastTests.fs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Fantomas.Extras\Fantomas.Extras.fsproj" />

src/Fantomas/CodePrinter.fs

@@ -1357,11 +1357,25 @@ and genExpr astContext synExpr ctx =
             +> ifElse (hasParenthesis e) sepNone sepSpace
             +> genExpr astContext e
         | TypedExpr (Downcast, e, t) ->
-            genExpr astContext e -- " :?> "
-            +> genType astContext false t
+            let shortExpr =
+                genExpr astContext e -- " :?> "
+                +> genType astContext false t
+
+            let longExpr =
+                genExpr astContext e +> sepNln -- ":?> "
+                +> genType astContext false t
+
+            expressionFitsOnRestOfLine shortExpr longExpr
         | TypedExpr (Upcast, e, t) ->
-            genExpr astContext e -- " :> "
-            +> genType astContext false t
+            let shortExpr =
+                genExpr astContext e -- " :> "
+                +> genType astContext false t
+
+            let longExpr =
+                genExpr astContext e +> sepNln -- ":> "
+                +> genType astContext false t
+
+            expressionFitsOnRestOfLine shortExpr longExpr
         | TypedExpr (Typed, e, t) ->
             genExpr astContext e
             +> sepColon