Fix tuple coercion (#7024)

* Fix tuple coercion

It was only handled for the first arg in the tuple

* Update CHANGELOG

Author: shulhi

CHANGELOG.md

@@ -18,6 +18,7 @@
 - Disallow spreading anything but regular variants inside of other variants. https://github.com/rescript-lang/rescript-compiler/pull/6980
 - Fix comment removed when function signature has `type` keyword. https://github.com/rescript-lang/rescript-compiler/pull/6997
 - Fix parse error on doc comment before "and" in type def. https://github.com/rescript-lang/rescript-compiler/pull/7001
+- Fix tuple coercion. https://github.com/rescript-lang/rescript-compiler/pull/7024
 
 # 11.1.3
 

jscomp/syntax/src/res_core.ml

@@ -1865,6 +1865,7 @@ and parseConstrainedExprRegion p =
   | token when Grammar.isExprStart token -> (
     let expr = parseExpr p in
     match p.Parser.token with
+    | ColonGreaterThan -> Some (parseCoercedExpr ~expr p)
     | Colon ->
       Parser.next p;
       let typ = parseTypExpr p in

jscomp/syntax/tests/parsing/grammar/expressions/coerce.res

@@ -1,3 +1,11 @@
 let foo = (x:int) => (x :> int)
 
-let foo = x => (x : t :> int)
+let foo = x => (x : t :> int)
+
+let _ = (x : int)
+
+let foo = (x : int, y :> float)
+
+let foo = (x : int, y :> float, z :> int)
+
+let foo = (x : int, y, z :> int)

jscomp/syntax/tests/parsing/grammar/expressions/expected/coerce.res.txt

@@ -1,2 +1,6 @@
 let foo (x : int) = (x :> int)
-let foo x = ((x : t) :> int)
+let foo x = ((x : t) :> int)
+let _ = (x : int)
+let foo = ((x : int), (y :> float))
+let foo = ((x : int), (y :> float), (z :> int))
+let foo = ((x : int), y, (z :> int))