Remove line break in 'M with module N = N (* cmt *)' (#2779)

Improve the formatting of:

    module type of M
      with module A = A (*test*)

Author: Julow

CHANGES.md

@@ -63,6 +63,8 @@ profile. This started with version 0.26.0.
   instead of only some.
   (#2737, @v-gb)
 
+- Remove line break in `M with module N = N (* cmt *)` (#2779, @Julow)
+
 ### Internal
 
 - Added information on writing tests to `CONTRIBUTING.md` (#2838, @WardBrian)

lib/Fmt_ast.ml

@@ -262,7 +262,8 @@ let rec fmt_longident c (li : Longident.t) =
         $ wrap (cut_break $ str "(") (str ")") (fmt_longident_loc c li2) )
 
 and fmt_longident_loc c ?pre {txt; loc} =
-  Cmts.fmt c loc (opt pre str $ fmt_longident c txt)
+  let box = if Cmts.has_after c.cmts loc then hvbox 0 else Fn.id in
+  box (Cmts.fmt c loc (opt pre str $ fmt_longident c txt))
 
 let str_longident c x =
   Format_.asprintf "%a" (fun fs x -> eval fs (fmt_longident c x)) x

test/passing/refs.ahrefs/module_type.ml.err

@@ -1,2 +1,2 @@
-Warning: module_type.ml:38 exceeds the margin
-Warning: module_type.ml:77 exceeds the margin
+Warning: module_type.ml:36 exceeds the margin
+Warning: module_type.ml:75 exceeds the margin

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

@@ -26,10 +26,8 @@ end
 
 module type M =
   module type of M
-    with module A := A
-    (*test*)
-     and module A = A
-    (*test*)
+    with module A := A (*test*)
+     and module A = A (*test*)
      and module A = A
     with module A = A
     (*test*)

test/passing/refs.default/module_type.ml.err

@@ -1,2 +1,2 @@
-Warning: module_type.ml:35 exceeds the margin
-Warning: module_type.ml:71 exceeds the margin
+Warning: module_type.ml:33 exceeds the margin
+Warning: module_type.ml:69 exceeds the margin

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

@@ -23,10 +23,8 @@ end
 
 module type M =
   module type of M
-    with module A := A
-    (*test*)
-     and module A = A
-    (*test*)
+    with module A := A (*test*)
+     and module A = A (*test*)
      and module A = A
     with module A = A
     (*test*)

test/passing/refs.janestreet/module_type.ml.err

@@ -1 +1 @@
-Warning: module_type.ml:36 exceeds the margin
+Warning: module_type.ml:34 exceeds the margin

test/passing/refs.janestreet/module_type.ml.ref

@@ -24,10 +24,8 @@ end
 
 module type M =
   module type of M
-  with module A := A
-  (*test*)
-   and module A = A
-  (*test*)
+  with module A := A (*test*)
+   and module A = A (*test*)
    and module A = A
   with module A = A
   (*test*)

test/passing/refs.ocamlformat/module_type.ml.err

@@ -1,2 +1,2 @@
-Warning: module_type.ml:38 exceeds the margin
-Warning: module_type.ml:75 exceeds the margin
+Warning: module_type.ml:36 exceeds the margin
+Warning: module_type.ml:73 exceeds the margin

test/passing/refs.ocamlformat/module_type.ml.ref

@@ -26,10 +26,8 @@ end
 
 module type M =
   module type of M
-    with module A := A
-    (*test*)
-     and module A = A
-    (*test*)
+    with module A := A (*test*)
+     and module A = A (*test*)
      and module A = A
     with module A = A
     (*test*)