ocamlPackages.gen_js_api: init at 1.0.9

I chose 1.0.9 instead of the latest 1.1.0, to avoid having to upgrade
js_of_ocaml first.

pkgs/development/ocaml-modules/gen_js_api/default.nix

@@ -0,0 +1,41 @@
+{ buildDunePackage
+, lib
+, ppxlib
+, fetchFromGitHub
+, ojs
+, js_of_ocaml-compiler
+, nodejs
+}:
+
+buildDunePackage rec {
+  pname = "gen_js_api";
+  version = "1.0.9";
+
+  src = fetchFromGitHub {
+    owner = "LexiFi";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "1qx6if1avr484bl9x1h0cksdc6gqw5i4pwzdr27h46hppnnvi8y8";
+  };
+
+  minimalOCamlVersion = "4.08";
+
+  propagatedBuildInputs = [ ojs ppxlib ];
+  checkInputs = [ js_of_ocaml-compiler nodejs ];
+  doCheck = true;
+
+  meta = {
+    homepage = "https://github.com/LexiFi/gen_js_api";
+    description = "Easy OCaml bindings for JavaScript libraries";
+    longDescription = ''
+      gen_js_api aims at simplifying the creation of OCaml bindings for
+      JavaScript libraries. Authors of bindings write OCaml signatures for
+      JavaScript libraries and the tool generates the actual binding code with a
+      combination of implicit conventions and explicit annotations.
+
+      gen_js_api is to be used with the js_of_ocaml compiler.
+    '';
+    license = lib.licenses.mit;
+    maintainers = [ lib.maintainers.bcc32 ];
+  };
+}

pkgs/development/ocaml-modules/gen_js_api/ojs.nix

@@ -0,0 +1,21 @@
+{ buildDunePackage
+, gen_js_api
+}:
+
+buildDunePackage rec {
+  pname = "ojs";
+
+  inherit (gen_js_api) version src;
+
+  doCheck = false; # checks depend on gen_js_api, which is a cycle
+
+  minimalOCamlVersion = "4.08";
+
+  meta = {
+    inherit (gen_js_api.meta) homepage license maintainers;
+    description = "Runtime Library for gen_js_api generated libraries";
+    longDescription = ''
+      To be used in conjunction with gen_js_api
+    '';
+  };
+}

pkgs/top-level/ocaml-packages.nix

@@ -510,6 +510,8 @@ let
 
     gapi_ocaml = callPackage ../development/ocaml-modules/gapi-ocaml { };
 
+    gen_js_api = callPackage ../development/ocaml-modules/gen_js_api { };
+
     gg = callPackage ../development/ocaml-modules/gg { };
 
     git = callPackage ../development/ocaml-modules/git {
@@ -1000,6 +1002,8 @@ let
 
     odoc-parser = callPackage ../development/ocaml-modules/odoc-parser { };
 
+    ojs = callPackage ../development/ocaml-modules/gen_js_api/ojs.nix { };
+
     omd = callPackage ../development/ocaml-modules/omd { };
 
     opam-core = callPackage ../development/ocaml-modules/opam-core {