Fix vertical breaks in let-in with comments before 'in'

lib/Fmt_ast.ml

@@ -4876,7 +4876,7 @@ and fmt_value_binding c ~ctx0 ~rec_flag ?in_ ?epi
         , fmt_item_attributes c ~pre:(Break (1, 2)) at_at_attrs $ in_ indent
         , fmt_opt epi
         , Cmts.fmt_before c lb_loc
-        , Cmts.fmt_after c lb_loc ~pro:force_break )
+        , Cmts.fmt_after c lb_loc ~pro:(break 1 0) )
     | None ->
         let epi =
           fmt_item_attributes c ~pre:(Break (1, 0)) at_at_attrs $ fmt_opt epi
@@ -4955,7 +4955,7 @@ and fmt_value_binding c ~ctx0 ~rec_flag ?in_ ?epi
               ( hvbox_if toplevel indent decl_and_body
               $ cmts_after
               $ opt loc_in
-                  (Cmts.fmt_before c ~pro:force_break ~epi:noop ~eol:noop) )
+                  (Cmts.fmt_before c ~pro:(break 1 0) ~epi:noop ~eol:noop) )
           $ in_ )
       $ opt loc_in (Cmts.fmt_after ~pro:force_break c)
       $ epi )

test/passing/refs.ahrefs/let_binding-deindent-fun.ml.ref

@@ -300,3 +300,22 @@ let rewrite_export =
   let+ (a, b) : a * b = () in
   ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+  use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+  use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+  in
+  use some_long_variable_name
+;;

test/passing/refs.ahrefs/let_binding-in_indent.ml.ref

@@ -300,3 +300,22 @@ let rewrite_export =
           let+ (a, b) : a * b = () in
               ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+      use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+      use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+  in
+      use some_long_variable_name
+;;

test/passing/refs.ahrefs/let_binding-indent.ml.ref

@@ -300,3 +300,22 @@ let rewrite_export =
   let+ (a, b) : a * b = () in
   ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+  use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+  use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+in
+  use some_long_variable_name
+;;

test/passing/refs.ahrefs/let_binding.ml.ref

@@ -300,3 +300,22 @@ let rewrite_export =
   let+ (a, b) : a * b = () in
   ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+  use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+  use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+  in
+  use some_long_variable_name
+;;

test/passing/refs.ahrefs/let_punning-denied.ml.ref

@@ -22,16 +22,10 @@ let q =
 
 let r =
   let* (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *)
-  and* (* 5 *) y =
-    y
-    (* 6 *)
-  in
+  and* (* 5 *) y = y (* 6 *) in
   x, y
 
 let s =
   let%foo (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *)
-  and (* 5 *) y =
-    y
-    (* 6 *)
-  in
+  and (* 5 *) y = y (* 6 *) in
   x, y

test/passing/refs.ahrefs/let_punning-preferred.ml.ref

@@ -26,9 +26,7 @@ let r =
     (* 3 *) x
   (* 2 *)
   (* 4 *)
-  and* (* 5 *) y
-    (* 6 *)
-  in
+  and* (* 5 *) y (* 6 *) in
   x, y
 
 let s =
@@ -37,7 +35,5 @@ let s =
     (* 3 *) x
   (* 2 *)
   (* 4 *)
-  and (* 5 *) y
-    (* 6 *)
-  in
+  and (* 5 *) y (* 6 *) in
   x, y

test/passing/refs.ahrefs/let_punning.ml.ref

@@ -22,14 +22,10 @@ let q =
 
 let r =
   let* (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *)
-  and* (* 5 *) y
-    (* 6 *)
-  in
+  and* (* 5 *) y (* 6 *) in
   x, y
 
 let s =
   let%foo (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *)
-  and (* 5 *) y
-    (* 6 *)
-  in
+  and (* 5 *) y (* 6 *) in
   x, y

test/passing/refs.default/let_binding-deindent-fun.ml.ref

@@ -273,3 +273,22 @@ let rewrite_export =
   let+ (a, b) : a * b = () in
   ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+  use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+  use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+  in
+  use some_long_variable_name
+;;

test/passing/refs.default/let_binding-in_indent.ml.ref

@@ -273,3 +273,22 @@ let rewrite_export =
           let+ (a, b) : a * b = () in
               ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+      use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+      use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+  in
+      use some_long_variable_name
+;;

test/passing/refs.default/let_binding-indent.ml.ref

@@ -274,3 +274,22 @@ let rewrite_export =
       let+ (a, b) : a * b = () in
       ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+      let threshold = 3 (* max depth *) in
+      use threshold
+;;
+
+let () =
+      let left _ = true (* value vs nothing *) in
+      use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+      let some_long_variable_name =
+            some_long_expression_value (* a long comment forcing a break *)
+      in
+      use some_long_variable_name
+;;

test/passing/refs.default/let_binding.ml.ref

@@ -273,3 +273,22 @@ let rewrite_export =
   let+ (a, b) : a * b = () in
   ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+  use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+  use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+  in
+  use some_long_variable_name
+;;

test/passing/refs.default/let_punning-denied.ml.ref

@@ -14,17 +14,9 @@ let q =
   (x, y, z)
 
 let r =
-  let* (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *)
-  and* (* 5 *) y =
-    y
-    (* 6 *)
-  in
+  let* (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *) and* (* 5 *) y = y (* 6 *) in
   (x, y)
 
 let s =
-  let%foo (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *)
-  and (* 5 *) y =
-    y
-    (* 6 *)
-  in
+  let%foo (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *) and (* 5 *) y = y (* 6 *) in
   (x, y)

test/passing/refs.default/let_punning-preferred.ml.ref

@@ -16,12 +16,9 @@ let q =
 let r =
   let*
       (* 1 *)
-      (* 3 *) x
-  (* 2 *)
+      (* 3 *) x (* 2 *)
   (* 4 *)
-  and* (* 5 *) y
-    (* 6 *)
-  in
+  and* (* 5 *) y (* 6 *) in
   (x, y)
 
 let s =
@@ -30,7 +27,5 @@ let s =
       (* 3 *) x
   (* 2 *)
   (* 4 *)
-  and (* 5 *) y
-    (* 6 *)
-  in
+  and (* 5 *) y (* 6 *) in
   (x, y)

test/passing/refs.default/let_punning.ml.ref

@@ -14,15 +14,9 @@ let q =
   (x, y, z)
 
 let r =
-  let* (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *)
-  and* (* 5 *) y
-    (* 6 *)
-  in
+  let* (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *) and* (* 5 *) y (* 6 *) in
   (x, y)
 
 let s =
-  let%foo (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *)
-  and (* 5 *) y
-    (* 6 *)
-  in
+  let%foo (* 1 *) x (* 2 *) = (* 3 *) x (* 4 *) and (* 5 *) y (* 6 *) in
   (x, y)

test/passing/refs.janestreet/let_binding-deindent-fun.ml.ref

@@ -326,3 +326,22 @@ let rewrite_export =
   let+ (a, b) : a * b = () in
   ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+  use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+  use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+  in
+  use some_long_variable_name
+;;

test/passing/refs.janestreet/let_binding-in_indent.ml.ref

@@ -326,3 +326,22 @@ let rewrite_export =
           let+ (a, b) : a * b = () in
               ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+  let threshold = 3 (* max depth *) in
+      use threshold
+;;
+
+let () =
+  let left _ = true (* value vs nothing *) in
+      use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+  let some_long_variable_name =
+    some_long_expression_value (* a long comment forcing a break *)
+  in
+      use some_long_variable_name
+;;

test/passing/refs.janestreet/let_binding-indent.ml.ref

@@ -326,3 +326,22 @@ let rewrite_export =
       let+ (a, b) : a * b = () in
       ()
 ;;
+
+(* Comment before in should stay on same line when it fits *)
+let () =
+      let threshold = 3 (* max depth *) in
+      use threshold
+;;
+
+let () =
+      let left _ = true (* value vs nothing *) in
+      use left
+;;
+
+(* Comment before in that does not fit should break *)
+let () =
+      let some_long_variable_name =
+            some_long_expression_value (* a long comment forcing a break *)
+      in
+      use some_long_variable_name
+;;