Avoid breaking between text nodes

lib/xml_print.ml

@@ -267,6 +267,10 @@ struct
       close_box indent fmt
     end
 
+  let elt_needs_cut = function
+    | Comment _ | Node _ | Leaf _ -> true
+    | Entity _ | PCDATA _ | EncodedPCDATA _ | Empty -> false
+
   let rec pp_tag encode indent fmt tag attrs children =
     match children with
     | [] -> pp_closedtag encode indent fmt tag attrs
@@ -276,13 +280,13 @@ struct
         (open_box indent)
         (pp_tag_and_attribs encode indent) (tag, attrs)
         (cut indent)
-        (pp_elts encode indent) children
+        (pp_elts true encode indent) children
         (close_box indent)
         (cut indent)
         tag ;
       close_box indent fmt
 
-  and pp_elt encode indent fmt elt = match content elt with
+  and pp_elt encode indent fmt = function
     | Comment texte ->
       Format.fprintf fmt "<!--%s-->" (escape_comment texte)
 
@@ -303,10 +307,18 @@ struct
 
     | Empty -> ()
 
-  and pp_elts encode indent =
-    Format.pp_print_list
-      ~pp_sep:(fun fmt () -> cut indent fmt)
-      (pp_elt encode indent)
+  and pp_elts prev_did_cut encode indent fmt = function
+    | elt :: tl ->
+      let elt = content elt in
+      let need_cut = elt_needs_cut elt in
+      if not prev_did_cut && need_cut then cut indent fmt;
+      pp_elt encode indent fmt elt;
+      if need_cut then cut indent fmt;
+      pp_elts need_cut encode indent fmt tl
+    | [] -> ()
+
+  let pp_elt encode indent fmt elt =
+    pp_elt encode indent fmt (content elt)
 
   let pp ?(encode=encode_unsafe_char) ?(indent=false) () =
     pp_elt encode indent

test/test_html.ml

@@ -82,11 +82,28 @@ let escaping = "html escaping", tyxml_tests Html.[
 
 ]
 
+let indent = "html indent", tyxml_tests ~indent:true Html.[
+  "no break between text nodes",
+  p [ 
+    span ~a:[ a_class [ "some padding ............................" ] ] [
+      txt "some text here"; txt ". and here"
+    ]
+  ],
+  "<p>\n <span class=\"some padding ............................\">\n  some text here. and here\n </span>\n</p>";
+
+  "no break between inline nodes (failing)",
+  p ~a:[ a_class [ "some padding ............................" ] ] [ 
+    txt "some text here"; span [ txt ". and here" ]
+  ],
+  "<p class=\"some padding ............................\">some text here\n <span>. and here</span>\n</p>"
+
+]
 
 let tests = [
   html_elements ;
   html_attributes ;
   escaping ;
+  indent ;
 ]
 
 let () = Alcotest.run "tyxml" tests

test/tyxml_test.ml

@@ -2,11 +2,11 @@ open Tyxml
 
 (* Basic alcotest machinery *)
 
-let to_string = Format.asprintf "%a" (Html.pp_elt ())
+let to_string ?indent = Format.asprintf "%a" (Html.pp_elt ?indent ())
 
-let tyxml_tests l =
+let tyxml_tests ?indent l =
   let f (name, (ty : Html_types.body_content Html.elt), s) =
-    name, `Quick, fun () -> Alcotest.(check string) name (to_string ty) s
+    name, `Quick, fun () -> Alcotest.(check string) name (to_string ?indent ty) s
   in
   List.map f l