Fix signature help in uncurried mode

CHANGELOG.md

@@ -28,6 +28,7 @@
 - Don't emit object keys in uppercase as namespace. https://github.com/rescript-lang/rescript-vscode/pull/798
 - Fix accidental output of extra `|` when producing exhaustive switch code for polyvariants. https://github.com/rescript-lang/rescript-vscode/pull/805
 - Fix JS syntax highlighting in single-line FFI extension points. https://github.com/rescript-lang/rescript-vscode/pull/807
+- Fix signature help in uncurried mode. https://github.com/rescript-lang/rescript-vscode/pull/809
 
 ## 1.18.0
 

analysis/src/SignatureHelp.ml

@@ -39,10 +39,23 @@ let findFunctionType ~currentFile ~debug ~path ~pos =
 let extractParameters ~signature ~typeStrForParser ~labelPrefixLen =
   match signature with
   | [
-   {
-     Parsetree.psig_desc =
-       Psig_value {pval_type = {ptyp_desc = Ptyp_arrow _} as expr};
-   };
+   ( {
+       Parsetree.psig_desc =
+         Psig_value {pval_type = {ptyp_desc = Ptyp_arrow _} as expr};
+     }
+   | {
+       psig_desc =
+         Psig_value
+           {
+             pval_type =
+               {
+                 ptyp_desc =
+                   Ptyp_constr
+                     ( {txt = Lident "function$"},
+                       [({ptyp_desc = Ptyp_arrow _} as expr); _] );
+               };
+           };
+     } );
   ] ->
     let rec extractParams expr params =
       match expr with
@@ -262,7 +275,7 @@ let signatureHelp ~path ~pos ~currentFile ~debug =
         | {
          pexp_desc =
            Pexp_apply
-             ( {pexp_desc = Pexp_ident {txt = Lident "|."}},
+             ( {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")}},
                [
                  _;
                  ( _,

analysis/tests/src/SignatureHelpUncurried.res

@@ -0,0 +1,78 @@
+@@uncurried
+
+type someVariant = One | Two | Three
+
+/** Does stuff. */
+let someFunc = (one: int, ~two: option<string>=?, ~three: unit => unit, ~four: someVariant, ()) => {
+  ignore(one)
+  ignore(two)
+  ignore(three())
+  ignore(four)
+}
+
+let otherFunc = (first: string, second: int, third: float) => {
+  ignore(first)
+  ignore(second)
+  ignore(third)
+}
+
+// let _ = someFunc(
+//                  ^she
+
+// let _ = someFunc(1
+//                   ^she
+
+// let _ = someFunc(123, ~two
+//                           ^she
+
+// let _ = someFunc(123, ~two="123"
+//                               ^she
+
+// let _ = someFunc(123, ~two="123", ~four
+//                                    ^she
+
+// let _ = someFunc(123, ~two="123", ~four=O
+//                                        ^she
+
+// let _ = otherFunc(
+//                   ^she
+
+// let _ = otherFunc("123"
+//                      ^she
+
+// let _ = otherFunc("123", 123, 123.0)
+//                                 ^she
+
+// let _ = Completion.Lib.foo(~age
+//                               ^she
+
+let iAmSoSpecial = (iJustHaveOneArg: string) => {
+  ignore(iJustHaveOneArg)
+}
+
+// let _ = iAmSoSpecial(
+//                      ^she
+
+// let _ = "hello"->otherFunc(1
+//                             ^she
+
+let fn = (age: int, name: string, year: int) => {
+  ignore(age)
+  ignore(name)
+  ignore(year)
+}
+
+// let _ = fn(22, )
+//               ^she
+
+// let _ = fn(22, , 2023)
+//               ^she
+
+// let _ = fn(12, "hello", )
+//                        ^she
+
+// let _ = fn({ iAmSoSpecial() })
+//                           ^she
+
+// let _ = fn({ iAmSoSpecial({ someFunc() }) })
+//                                      ^she