From 3d8ca494957b51cac5568b3cc0d6fc56053fb90a Mon Sep 17 00:00:00 2001
From: Shulhi Sapli <shulhi@gmail.com>
Date: Sun, 8 Sep 2024 15:18:54 +0800
Subject: [PATCH] Fix tuple coercion (#7024)

* Fix tuple coercion

It was only handled for the first arg in the tuple

* Update CHANGELOG
---
 CHANGELOG.md                                           |  1 +
 jscomp/syntax/src/res_core.ml                          |  1 +
 .../tests/parsing/grammar/expressions/coerce.res       | 10 +++++++++-
 .../grammar/expressions/expected/coerce.res.txt        |  6 +++++-
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fd67e60ee4..bf653d33ed 100644
--- a/CHANGELOG.md
+++ b/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
 
diff --git a/jscomp/syntax/src/res_core.ml b/jscomp/syntax/src/res_core.ml
index 37e01e56e3..2a0807416c 100644
--- a/jscomp/syntax/src/res_core.ml
+++ b/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
diff --git a/jscomp/syntax/tests/parsing/grammar/expressions/coerce.res b/jscomp/syntax/tests/parsing/grammar/expressions/coerce.res
index e9f73bbf27..f2bd210eff 100644
--- a/jscomp/syntax/tests/parsing/grammar/expressions/coerce.res
+++ b/jscomp/syntax/tests/parsing/grammar/expressions/coerce.res
@@ -1,3 +1,11 @@
 let foo = (x:int) => (x :> int)
 
-let foo = x => (x : t :> int)
\ No newline at end of file
+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)
diff --git a/jscomp/syntax/tests/parsing/grammar/expressions/expected/coerce.res.txt b/jscomp/syntax/tests/parsing/grammar/expressions/expected/coerce.res.txt
index fd68e3581a..f87fc15a75 100644
--- a/jscomp/syntax/tests/parsing/grammar/expressions/expected/coerce.res.txt
+++ b/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)
\ No newline at end of file
+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))
\ No newline at end of file