Fix printing of uncurried application when the lhs is a function definition.

Author: cristianoc

CHANGELOG.md

@@ -58,6 +58,7 @@ These are only breaking changes for unformatted code.
 - Fix issue with integer overflow check https://github.com/rescript-lang/rescript-compiler/pull/6028
 - Make internal encoding of locations aware of unicode https://github.com/rescript-lang/rescript-compiler/pull/6073
 - Fix issue where `foo(x,_)` in uncurried mode would generate a curried function https://github.com/rescript-lang/rescript-compiler/pull/6082
+- Fix printing of uncurried application when the lhs is a function definition https://github.com/rescript-lang/rescript-compiler/pull/6084
 
 #### :nail_care: Polish
 

res_syntax/src/res_parens.ml

@@ -55,6 +55,7 @@ let callExpr expr =
        | Pexp_try _ | Pexp_while _ | Pexp_for _ | Pexp_ifthenelse _ );
     } ->
       Parenthesized
+    | _ when Ast_uncurried.exprIsUncurriedFun expr -> Parenthesized
     | _ when ParsetreeViewer.hasAwaitAttribute expr.pexp_attributes ->
       Parenthesized
     | _ -> Nothing)

res_syntax/tests/printer/expr/UncurriedByDefault.res

@@ -57,6 +57,9 @@ let t4 = (. type a b) => (l: list<a>, x: a) => list{x, ...l}
 let t5 = (type a b) => (. l: list<a>, x: a) => list{x, ...l}
 let t6 = (. type a b) => (. l: list<a>, x: a) => list{x, ...l}
 
+let () = (x => ignore(x))(3)
+let () = ((. x) => ignore(x))(. 3)
+
 @@uncurried.swap
 
 let cApp = foo(. 3)
@@ -115,3 +118,6 @@ let t0 = (type a b, l: list<a>, x: a) => list{x, ...l}
 let t1 = (. type a b, l: list<a>, x: a) => list{x, ...l}
 let t2 = (type a b, . l: list<a>, x: a) => list{x, ...l}
 let t3 = (. type a b, . l: list<a>, x: a) => list{x, ...l}
+
+let () = (x => ignore(x))(3)
+let () = ((. x) => ignore(x))(. 3)

res_syntax/tests/printer/expr/expected/UncurriedByDefault.res.txt

@@ -57,6 +57,9 @@ let t4 = (type a b, l: list<a>, x: a) => list{x, ...l}
 let t5 = (. type a b, l: list<a>, x: a) => list{x, ...l}
 let t6 = (. type a b, l: list<a>, x: a) => list{x, ...l}
 
+let () = (x => ignore(x))(3)
+let () = ((. x) => ignore(x))(. 3)
+
 @@uncurried.swap
 
 let cApp = foo(. 3)
@@ -115,3 +118,6 @@ let t0 = (type a b, l: list<a>, x: a) => list{x, ...l}
 let t1 = (. type a b, l: list<a>, x: a) => list{x, ...l}
 let t2 = (. type a b, l: list<a>, x: a) => list{x, ...l}
 let t3 = (. type a b, l: list<a>, x: a) => list{x, ...l}
+
+let () = (x => ignore(x))(3)
+let () = ((. x) => ignore(x))(. 3)