melange-re · anmonteiro · Jan 4, 2024 · Jan 4, 2024 · Jan 4, 2024 · Jan 4, 2024
diff --git a/Changes.md b/Changes.md
@@ -134,6 +134,9 @@ Unreleased
 - Upgrade the Melange JS parser to [Flow
   v0.225.1](https://github.com/facebook/flow/releases/tag/v0.225.1)
   ([#1012](https://github.com/melange-re/melange/pull/1012))
+- fix: add a newline after `%mel.raw` expressions to avoid breaking JS output
+  when they contain single line comments
+  ([#1017](https://github.com/melange-re/melange/pull/1017))
 
 2.2.0 2023-12-05
 ---------------

diff --git a/jscomp/core/js_dump.ml b/jscomp/core/js_dump.ml
@@ -663,7 +663,9 @@ and expression_desc cxt ~(level : int) x : cxt =
           in
           if raw_paren then string cxt L.lparen;
           string cxt s;
-          if raw_paren then string cxt L.rparen;
+          if raw_paren then (
+            newline cxt;
+            string cxt L.rparen);
           cxt
       | Stmt stmt_info ->
           if stmt_info = Js_stmt_comment then string cxt s

diff --git a/jscomp/core/js_exp_make.ml b/jscomp/core/js_exp_make.ml
@@ -139,7 +139,15 @@ let unicode ?loc ?comment s : t = make_expression ?loc ?comment (Unicode s)
 
 let raw_js_code ?loc ?comment info s : t =
   make_expression ?loc ?comment
-    (Raw_js_code { code = String.trim s; code_info = info })
+    (Raw_js_code
+       {
+         code =
+           (* FIXME: save one allocation
+              trim can not be done before syntax checking
+              otherwise location is incorrect *)
+           String.trim s;
+         code_info = info;
+       })
 
 let array ?loc ?comment mt es : t =
   make_expression ?loc ?comment (Array (es, mt))

diff --git a/jscomp/core/lam_compile_primitive.ml b/jscomp/core/lam_compile_primitive.ml
@@ -44,12 +44,7 @@ let translate loc (cxt : Lam_compile_context.t) (prim : Lam_primitive.t)
   | Pwrap_exn ->
       E.runtime_call Js_runtime_modules.caml_js_exceptions
         "internalToOCamlException" args
-  | Praw_js_code { code; code_info } ->
-      E.raw_js_code code_info code
-      (* FIXME: save one allocation
-         trim can not be done before syntax checking
-         otherwise location is incorrect
-      *)
+  | Praw_js_code { code; code_info } -> E.raw_js_code code_info code
   | Pjs_runtime_apply -> (
       match args with [ f; args ] -> E.flat_call f args | _ -> assert false)
   | Pjs_apply -> (

diff --git a/jscomp/test/dist/jscomp/test/bs_hashtbl_string_test.js b/jscomp/test/dist/jscomp/test/bs_hashtbl_string_test.js
diff --git a/jscomp/test/dist/jscomp/test/bs_node_string_buffer_test.js b/jscomp/test/dist/jscomp/test/bs_node_string_buffer_test.js
diff --git a/jscomp/test/dist/jscomp/test/caml_compare_test.js b/jscomp/test/dist/jscomp/test/caml_compare_test.js
diff --git a/jscomp/test/dist/jscomp/test/epsilon_test.js b/jscomp/test/dist/jscomp/test/epsilon_test.js
diff --git a/jscomp/test/dist/jscomp/test/exception_raise_test.js b/jscomp/test/dist/jscomp/test/exception_raise_test.js
diff --git a/jscomp/test/dist/jscomp/test/ffi_arity_test.js b/jscomp/test/dist/jscomp/test/ffi_arity_test.js
diff --git a/jscomp/test/dist/jscomp/test/ffi_js_test.js b/jscomp/test/dist/jscomp/test/ffi_js_test.js
diff --git a/jscomp/test/dist/jscomp/test/flow_parser_reg_test.js b/jscomp/test/dist/jscomp/test/flow_parser_reg_test.js
diff --git a/jscomp/test/dist/jscomp/test/gpr_2682_test.js b/jscomp/test/dist/jscomp/test/gpr_2682_test.js
diff --git a/jscomp/test/dist/jscomp/test/gpr_4442_test.js b/jscomp/test/dist/jscomp/test/gpr_4442_test.js
diff --git a/jscomp/test/dist/jscomp/test/polymorphic_raw_test.js b/jscomp/test/dist/jscomp/test/polymorphic_raw_test.js
diff --git a/jscomp/test/dist/jscomp/test/raw_output_test.js b/jscomp/test/dist/jscomp/test/raw_output_test.js
diff --git a/jscomp/test/dist/jscomp/test/re_or_res/reasonReactOptimizedCreateClass.js b/jscomp/test/dist/jscomp/test/re_or_res/reasonReactOptimizedCreateClass.js
diff --git a/jscomp/test/dist/jscomp/test/string_interp_test.js b/jscomp/test/dist/jscomp/test/string_interp_test.js
diff --git a/jscomp/test/dist/jscomp/test/unsafe_ppx_test.js b/jscomp/test/dist/jscomp/test/unsafe_ppx_test.js
diff --git a/test/blackbox-tests/melange-ppx-raw.t b/test/blackbox-tests/melange-ppx-raw.t
@@ -31,3 +31,24 @@ Adding a callback breaks
                             ^^^^^^^^^^^^^^^^^^^^^^
   Error: `%mel.raw' can only be applied to a string
   [1]
+
+Show expressions in `%mel.raw` get wrapped in parentheses with proper syntax
+
+  $ cat > main.ml <<EOF
+  > let () = [%mel.raw {|
+  > // before
+  > f(1,2)
+  > // after
+  > |}]
+  > EOF
+  $ melc -ppx melppx main.ml
+  // Generated by Melange
+  'use strict';
+
+
+  ((// before
+  f(1,2)
+  // after
+    ));
+
+  /*  Not a pure module */