Parens: Keep parens for problematic exprs in $"{(…):N0}", $"{(…),-3}", etc.

docs/release-notes/.FSharp.Compiler.Service/8.0.300.md

@@ -3,6 +3,7 @@
 * Code generated files with > 64K methods and generated symbols crash when loaded. Use infered sequence points for debugging. ([Issue #16399](https://github.com/dotnet/fsharp/issues/16399), [#PR 16514](https://github.com/dotnet/fsharp/pull/16514))
 * `nameof Module` expressions and patterns are processed to link files in `--test:GraphBasedChecking`. ([PR #16550](https://github.com/dotnet/fsharp/pull/16550))
 * Graph Based Checking doesn't throw on invalid parsed input so it can be used for IDE scenarios ([PR #16575](https://github.com/dotnet/fsharp/pull/16575))
+* Keep parens for problematic exprs (`if`, `match`, etc.) in `$"{(…):N0}"`, `$"{(…),-3}"`, etc. ([PR #16578](https://github.com/dotnet/fsharp/pull/16578))
 
 ### Added
 

src/Compiler/Service/SynExpr.fs

@@ -423,7 +423,9 @@ module SynExpr =
                 | SynExpr.MatchLambda(matchClauses = Last(SynMatchClause(resultExpr = expr)))
                 | SynExpr.MatchBang(clauses = Last(SynMatchClause(resultExpr = expr)))
                 | SynExpr.TryWith(withCases = Last(SynMatchClause(resultExpr = expr)))
-                | SynExpr.TryFinally(finallyExpr = expr) -> loop expr
+                | SynExpr.TryFinally(finallyExpr = expr)
+                | SynExpr.Do(expr = expr)
+                | SynExpr.DoBang(expr = expr) -> loop expr
                 | _ -> ValueNone
 
             loop
@@ -810,6 +812,12 @@ module SynExpr =
                 ->
                 true
 
+            | SynExpr.InterpolatedString(contents = contents), (SynExpr.Tuple(isStruct = false) | Dangling.Problematic _) ->
+                contents
+                |> List.exists (function
+                    | SynInterpolatedStringPart.FillExpr(qualifiers = Some _) -> true
+                    | _ -> false)
+
             | SynExpr.Record(copyInfo = Some(SynExpr.Paren(expr = Is inner), _)), Dangling.Problematic _
             | SynExpr.AnonRecd(copyInfo = Some(SynExpr.Paren(expr = Is inner), _)), Dangling.Problematic _ -> true
 

vsintegration/tests/FSharp.Editor.Tests/CodeFixes/RemoveUnnecessaryParenthesesTests.fs

@@ -800,6 +800,24 @@ in x
             "$\"{(id 3)}\"", "$\"{id 3}\""
             "$\"{(x)}\"", "$\"{x}\""
 
+            "$\"{(if true then 1 else 0)}\"", "$\"{if true then 1 else 0}\""
+            "$\"{(if true then 1 else 0):N0}\"", "$\"{(if true then 1 else 0):N0}\""
+            "$\"{(if true then 1 else 0),-3}\"", "$\"{(if true then 1 else 0),-3}\""
+            "$\"{(match () with () -> 1):N0}\"", "$\"{(match () with () -> 1):N0}\""
+            "$\"{(match () with () -> 1),-3}\"", "$\"{(match () with () -> 1),-3}\""
+            "$\"{(try () with _ -> 1):N0}\"", "$\"{(try () with _ -> 1):N0}\""
+            "$\"{(try () with _ -> 1),-3}\"", "$\"{(try () with _ -> 1),-3}\""
+            "$\"{(try 1 finally ()):N0}\"", "$\"{(try 1 finally ()):N0}\""
+            "$\"{(try 1 finally ()),-3}\"", "$\"{(try 1 finally ()),-3}\""
+            "$\"{(let x = 3 in x):N0}\"", "$\"{(let x = 3 in x):N0}\""
+            "$\"{(let x = 3 in x),-3}\"", "$\"{(let x = 3 in x),-3}\""
+            "$\"{(do (); 3):N0}\"", "$\"{(do (); 3):N0}\""
+            "$\"{(do (); 3),-3}\"", "$\"{(do (); 3),-3}\""
+            "$\"{(x <- 3):N0}\"", "$\"{(x <- 3):N0}\""
+            "$\"{(x <- 3),-3}\"", "$\"{(x <- 3),-3}\""
+            "$\"{(1, 2):N0}\"", "$\"{(1, 2):N0}\""
+            "$\"{(1, 2),-3}\"", "$\"{(1, 2),-3}\""
+
             """
             $"{(3 + LanguagePrimitives.GenericZero<int>):N0}"
             """,