Include blocks do not require an empty block anymore

Author: gpetiot

CHANGES.md

@@ -3,6 +3,7 @@
 #### Added
 
 - Allow to explicitly set the kind of blocks in labels: `ocaml`, `cram`, `toplevel` or `include`. (#237, @gpetiot)
+- Include blocks do not require an empty block anymore (#286, @gpetiot)
 
 #### Changed
 

lib/block.ml

@@ -33,6 +33,13 @@ module Header = struct
     | "bash" -> Some (Shell `Bash)
     | "ocaml" -> Some OCaml
     | s -> Some (Other s)
+
+  let infer_from_file file =
+    match Filename.(remove_extension (basename file), extension file) with
+    | ("dune" | "dune-project"), _ -> Some (Other "scheme")
+    | _, (".ml" | ".mli" | ".mlt" | ".eliom" | ".eliomi") -> Some OCaml
+    | _, ".sh" -> Some (Shell `Sh)
+    | _ -> None
 end
 
 type section = int * string
@@ -462,6 +469,14 @@ let mk ~line ~file ~column ~section ~labels ~legacy_labels ~header ~contents
     value;
   }
 
+let mk_include ~line ~file ~column ~section ~labels =
+  match get_label (function File x -> Some x | _ -> None) labels with
+  | Some file_inc ->
+      let header = Header.infer_from_file file_inc in
+      mk ~line ~file ~column ~section ~labels ~legacy_labels:false ~header
+        ~contents:[] ~errors:[]
+  | None -> label_required ~label:"file" ~kind:"include"
+
 let is_active ?section:s t =
   let active =
     match s with

lib/block.mli

@@ -22,6 +22,8 @@ module Header : sig
   val pp : Format.formatter -> t -> unit
 
   val of_string : string -> t option
+
+  val infer_from_file : string -> t option
 end
 
 (** Code blocks. *)
@@ -104,6 +106,16 @@ val mk :
   errors:Output.t list ->
   (t, [ `Msg of string ]) Result.result
 
+val mk_include :
+  line:int ->
+  file:string ->
+  column:int ->
+  section:section option ->
+  labels:Label.t list ->
+  (t, [ `Msg of string ]) Result.result
+(** [mk_include] builds an include block from a comment [<!-- $MDX ... -->]
+    that is not followed by a code block [``` ... ```]. *)
+
 (** {2 Printers} *)
 
 val dump : t Fmt.t

lib/compat.ml

@@ -77,6 +77,10 @@ module Filename = struct
   let extension name =
     let l = extension_len name in
     if l = 0 then "" else String.sub name (String.length name - l) l
+
+  let remove_extension name =
+    let l = extension_len name in
+    if l = 0 then name else String.sub name 0 (String.length name - l)
 #endif
 end
 

lib/lexer_mdx.mll

@@ -69,6 +69,19 @@ rule text section = parse
            List.iter (fun _ -> newline lexbuf) errors;
            newline lexbuf);
         `Block block :: text section lexbuf }
+  | "<!--" ws* "$MDX" ws* ([^' ' '\n']* as label_cmt) ws* "-->" ws* eol
+      { let labels = labels label_cmt in
+        let file = lexbuf.Lexing.lex_start_p.Lexing.pos_fname in
+        let column = lexbuf.Lexing.lex_start_p.Lexing.pos_cnum in
+        newline lexbuf;
+        let line = !line_ref in
+        newline lexbuf;
+        let block =
+          match Block.mk_include ~file ~line ~column ~section ~labels with
+          | Ok block -> block
+          | Error (`Msg msg) -> failwith msg
+        in
+        `Block block :: text section lexbuf }
   | ([^'\n']* as str) eol
       { newline lexbuf;
         `Text str :: text section lexbuf }

test/bin/mdx-test/expect/dune.inc

@@ -203,6 +203,18 @@
  (alias runtest)
  (action (diff heredoc/test-case.md heredoc.actual)))
 
+(rule
+ (target include-block.actual)
+ (deps (package mdx) (source_tree include-block))
+ (action
+  (with-stdout-to %{target}
+   (chdir include-block
+    (run ocaml-mdx test --output - test-case.md)))))
+
+(rule
+ (alias runtest)
+ (action (diff include-block/test-case.md.expected include-block.actual)))
+
 (rule
  (target labels-syntax.actual)
  (deps (package mdx) (source_tree labels-syntax))

test/bin/mdx-test/expect/include-block/code.mli

@@ -0,0 +1,3 @@
+type t
+
+val empty : t

test/bin/mdx-test/expect/include-block/dune

@@ -0,0 +1,7 @@
+We include files with MDX comments:
+
+<!-- $MDX file=code.mli -->
+
+<!-- $MDX file=dune -->
+
+<!-- $MDX file=../.ocamlformat -->

test/bin/mdx-test/expect/include-block/test-case.md

@@ -0,0 +1,18 @@
+We include files with MDX comments:
+
+<!-- $MDX file=code.mli -->
+```ocaml
+type t
+
+val empty : t
+```
+
+<!-- $MDX file=dune -->
+```scheme
+
+```
+
+<!-- $MDX file=../.ocamlformat -->
+```
+disable=true
+```