feat(fullstack): add fullstack support with Dream framework

.ocamlformat

@@ -1,4 +1,4 @@
 profile = default
 let-binding-spacing=double-semicolon
 break-infix-before-func=true
-version = 0.26.1
+version = 0.26.2

README.md

@@ -113,6 +113,16 @@ be coming soon! In the mean time, please check in at
 [The Caravan Discord](https://discord.gg/fNvVdsUWHE) for
 help getting started working on `create-melange-app`.
 
+<h3 id="run-locally">Run the CLI locally</h3>
+
+```bash
+npm install
+opam install . --dps-only
+dune build
+
+node ./build/src/cli.mjs
+```
+
 <div align="center">
 <a href="https://github.com/dmmulroy/create-melange-app/graphs/contributors">
   <img src="https://contrib.rocks/image?repo=dmmulroy/create-melange-app" />

create_melange_app.opam

@@ -17,6 +17,7 @@ depends: [
   "reason-react" {>= "0.15.0"}
   "reason-react-ppx"
   "ppx_deriving"
+  "ocamlformat" {= "0.26.2" & with-dev-setup}
   "odoc" {with-doc}
 ]
 build: [

dune-project

@@ -36,6 +36,10 @@
   (reason-react
    (>= 0.15.0))
   reason-react-ppx
-  ppx_deriving)
+  ppx_deriving
+  (ocamlformat
+   (and
+    (= 0.26.2)
+    :with-dev-setup)))
  (tags
   (cli, react, reasonml, ocaml, melange)))

src/core/app_module.ml

@@ -8,8 +8,7 @@ let template (configuration : Configuration.t) =
   in
   let name =
     match (configuration.syntax_preference, configuration.is_react_app) with
-    | `ReasonML, true 
-    | `ReasonML, false -> "App.re.tmpl"
+    | `ReasonML, true | `ReasonML, false -> "App.re.tmpl"
     | `OCaml, true -> "App.mlx.tmpl"
     | `OCaml, false -> "App.ml.tmpl"
   in

src/core/backend_files.ml

@@ -0,0 +1,84 @@
+open Bindings
+
+type backend_options = {
+  project_directory : string;
+  backend_framework : Configuration.backend_framework option;
+  project_name : string;
+}
+
+module Copy :
+  Process.S with type input = backend_options and type output = unit = struct
+  type input = backend_options
+  type output = unit
+
+  let name = "copy backend files"
+
+  let base_path =
+    Node.Path.join
+      [|
+        Nodejs.Util.__dirname [%mel.raw "import.meta.url"];
+        "..";
+        "templates";
+        "extensions";
+        "backend";
+        "dream";
+      |]
+  ;;
+
+  let error_message =
+    {|
+    Failed to copy backend files to project directory
+
+    The scaffolding process failed while copying backend files. Please try 
+    running `create-melange-app` again and choose to `Clear` the project 
+    directory created by this run.
+
+    If the problem persists, please open an issue at 
+    github.com/dmmulroy/create-melange-app/issues, and or join our discord for 
+    help at https://discord.gg/fNvVdsUWHE.
+  |}
+  ;;
+
+  let exec (input : input) =
+    match input.backend_framework with
+    | Some `Dream ->
+        let open Promise_result.Syntax.Let in
+        let backend_dest =
+          Node.Path.join [| input.project_directory; "backend" |]
+        in
+        let bin_dest = Node.Path.join [| backend_dest; "bin" |] in
+        let+ _ =
+          Fs_extra.ensureDir backend_dest |> Promise_result.of_js_promise
+        in
+        let+ _ = Fs_extra.ensureDir bin_dest |> Promise_result.of_js_promise in
+
+        let+ _ =
+          Fs_extra.copy
+            (Node.Path.join [| base_path; "bin"; "main.ml.tmpl" |])
+            (Node.Path.join [| bin_dest; "main.ml.tmpl" |])
+          |> Promise_result.of_js_promise
+        in
+        let+ _ =
+          Fs_extra.copy
+            (Node.Path.join [| base_path; "bin"; "dune.tmpl" |])
+            (Node.Path.join [| bin_dest; "dune.tmpl" |])
+          |> Promise_result.of_js_promise
+        in
+        let+ _ =
+          Fs_extra.copy
+            (Node.Path.join [| base_path; "dune.tmpl" |])
+            (Node.Path.join [| backend_dest; "dune.tmpl" |])
+          |> Promise_result.of_js_promise
+        in
+        let+ _ =
+          Fs_extra.copy
+            (Node.Path.join [| base_path; "README.md.tmpl" |])
+            (Node.Path.join [| backend_dest; "README.md.tmpl" |])
+          |> Promise_result.of_js_promise
+        in
+
+        Promise_result.resolve_ok ()
+        |> Promise_result.log_and_map_error (Fun.const error_message)
+    | None -> Promise_result.resolve_ok ()
+  ;;
+end

src/core/configuration.ml

@@ -22,11 +22,47 @@ let syntax_preference_of_string str =
   | _ -> failwith "Invalid syntax preference"
 ;;
 
+type project_type = [ `Frontend | `Fullstack ]
+
+let project_type_to_string = function
+  | `Frontend -> "Frontend"
+  | `Fullstack -> "Fullstack"
+;;
+
+let project_type_of_string str =
+  str |> String.lowercase_ascii
+  |> function
+  | "frontend" -> `Frontend
+  | "fullstack" -> `Fullstack
+  | _ -> failwith "Invalid project type"
+;;
+
+type backend_framework = [ `Dream ]
+
+let backend_framework_to_string = function `Dream -> "Dream"
+
+let backend_framework_of_string str =
+  str |> String.lowercase_ascii
+  |> function "dream" -> `Dream | _ -> failwith "Invalid backend framework"
+;;
+
+type api_features = [ `REST ]
+
+let api_features_to_string = function `REST -> "REST"
+
+let api_features_of_string str =
+  str |> String.lowercase_ascii
+  |> function "rest" -> `REST | _ -> failwith "Invalid API features"
+;;
+
 type t = {
   name : string;
   directory : string;
   node_package_manager : Nodejs.Process.npm_user_agent;
   syntax_preference : syntax_preference;
+  project_type : project_type;
+  backend_framework : backend_framework option;
+  api_features : api_features option;
   bundler : Bundler.t;
   is_react_app : bool;
   has_tests : bool;
@@ -36,13 +72,18 @@ type t = {
   overwrite : overwrite_preference option;
 }
 
-let make ~name ~directory ~syntax_preference ~bundler ~is_react_app ~has_tests
-    ~initialize_git ~initialize_npm ~initialize_ocaml_toolchain ~overwrite =
+let make ~name ~directory ~syntax_preference ~project_type ~bundler
+    ~is_react_app ~has_tests ~initialize_git ~initialize_npm
+    ~initialize_ocaml_toolchain ~overwrite ?(backend_framework = None)
+    ?(api_features = None) () =
   {
     name;
     directory;
     node_package_manager = Nodejs.Process.npm_config_user_agent;
     syntax_preference;
+    project_type;
+    backend_framework;
+    api_features;
     bundler;
     is_react_app;
     has_tests;
@@ -54,18 +95,35 @@ let make ~name ~directory ~syntax_preference ~bundler ~is_react_app ~has_tests
 ;;
 
 let set_overwrite overwrite config = { config with overwrite = Some overwrite }
+let is_fullstack config = config.project_type = `Fullstack
+let is_frontend_only config = config.project_type = `Frontend
 
 let to_string config =
+  let backend_info =
+    match config.project_type with
+    | `Frontend -> ""
+    | `Fullstack ->
+        Printf.sprintf "Backend framework: %s\nAPI features: %s\n"
+          (config.backend_framework
+          |> Option.map backend_framework_to_string
+          |> Option.value ~default:"None")
+          (config.api_features
+          |> Option.map api_features_to_string
+          |> Option.value ~default:"None")
+  in
   Printf.sprintf
     "Name: %s\n\
      Directory: %s\n\
-     Syntax preference: %s\n\
-     Bunder: %s\n\
+     Project type: %s\n\
+     %sSyntax preference: %s\n\
+     Bundler: %s\n\
      is_react_app: %b\n\
      Initialize git: %b\n\
      Initialize npm: %b\n\
      Initialize OCaml toolchain: %b\n"
     config.name config.directory
+    (project_type_to_string config.project_type)
+    backend_info
     (syntax_preference_to_string config.syntax_preference)
     (Bundler.to_string config.bundler)
     config.is_react_app config.initialize_git config.initialize_npm
@@ -83,6 +141,18 @@ let to_json (configuration : t) =
   Js.Dict.set dict "syntax_preference"
     (Js.Json.string
        (syntax_preference_to_string configuration.syntax_preference));
+  Js.Dict.set dict "project_type"
+    (Js.Json.string (project_type_to_string configuration.project_type));
+  (match configuration.backend_framework with
+  | Some framework ->
+      Js.Dict.set dict "backend_framework"
+        (Js.Json.string (backend_framework_to_string framework))
+  | None -> ());
+  (match configuration.api_features with
+  | Some features ->
+      Js.Dict.set dict "api_features"
+        (Js.Json.string (api_features_to_string features))
+  | None -> ());
   Js.Dict.set dict "bundler"
     (Js.Json.string
        (Bundler.to_string configuration.bundler |> String.capitalize_ascii));
@@ -106,6 +176,9 @@ type partial = {
   name : string option;
   directory : string option;
   syntax_preference : syntax_preference option;
+  project_type : project_type option;
+  backend_framework : backend_framework option;
+  api_features : api_features option;
   bundler : Bundler.t option;
   is_react_app : bool option;
   has_tests : bool option;
@@ -114,12 +187,16 @@ type partial = {
   initialize_ocaml_toolchain : bool option;
 }
 
-let make_partial ?name ?directory ?syntax_preference ?bundler ?is_react_app
-    ?has_tests ?initialize_git ?initialize_npm ?initialize_ocaml_toolchain () =
+let make_partial ?name ?directory ?syntax_preference ?project_type
+    ?backend_framework ?api_features ?bundler ?is_react_app ?has_tests
+    ?initialize_git ?initialize_npm ?initialize_ocaml_toolchain () =
   {
     name;
     directory;
     syntax_preference;
+    project_type;
+    backend_framework;
+    api_features;
     bundler;
     is_react_app;
     has_tests;

src/core/dune.ml

@@ -98,6 +98,10 @@ module Dune_project = struct
     let make ?version name = { name; version }
   end
 
+  let backend_dependencies =
+    [ Dependency.make "dream"; Dependency.make "lwt"; Dependency.make "yojson" ]
+  ;;
+
   let default_dependencies =
     [
       Dependency.make ~version:">= 5.1.1" "ocaml";
@@ -149,10 +153,23 @@ module Dune_project = struct
     Js.Json.object_ dict
   ;;
 
-  let template ~project_name ~project_directory ~is_mlx =
+  let make_with_backend_deps ~name ~is_fullstack =
+    let base_deps : Dependency.t String_map.t = default_dependencies in
+    let deps =
+      if is_fullstack then
+        List.fold_left
+          (fun acc (dep : Dependency.t) -> String_map.add dep.name dep acc)
+          base_deps backend_dependencies
+      else base_deps
+    in
+    { name; depends = deps; is_mlx = false }
+  ;;
+
+  let template ~project_name ~project_directory ~is_mlx:_
+      ?(is_fullstack = false) () =
     let template_directory = Node.Path.join [| project_directory; "./" |] in
     Template.make ~name:"dune-project.tmpl"
-      ~value:{ empty with name = project_name; is_mlx }
+      ~value:(make_with_backend_deps ~name:project_name ~is_fullstack)
       ~dir:template_directory ~to_json
   ;;
 end

src/core/engine.ml

@@ -93,6 +93,11 @@ let extend_dune_project_with_app_settings ~(is_react_app : bool)
            (Dune.Dune_project.add_dependencies React.Dune_project.dependencies)
 ;;
 
+let copy_backend_files ~backend_framework ~project_name project_directory =
+  let open Backend_files in
+  Copy.exec { project_directory; backend_framework; project_name }
+;;
+
 let copy_test_files ~syntax_preference ~is_react_app project_directory =
   let open Test_files in
   Copy.exec { project_directory; syntax_preference; is_react_app }
@@ -118,6 +123,43 @@ let extend_dune_project_with_tests ~(is_react_app : bool)
           (if is_react_app then Fest.Dune_project.react_dependencies else []))
 ;;
 
+let compile_backend_templates ~project_name ~project_directory =
+  let open Promise_result.Syntax.Let in
+  let backend_data = Js.Dict.empty () in
+  Js.Dict.set backend_data "name" (Js.Json.string project_name);
+  let backend_json = Js.Json.object_ backend_data in
+
+  let main_ml_template =
+    Template.make ~name:"main.ml.tmpl" ~value:backend_json
+      ~dir:(Node.Path.join [| project_directory; "backend"; "bin" |])
+      ~to_json:(fun x -> x)
+  in
+  let+ _ = Template.compile main_ml_template in
+
+  let bin_dune_template =
+    Template.make ~name:"dune.tmpl" ~value:backend_json
+      ~dir:(Node.Path.join [| project_directory; "backend"; "bin" |])
+      ~to_json:(fun x -> x)
+  in
+  let+ _ = Template.compile bin_dune_template in
+
+  let backend_dune_template =
+    Template.make ~name:"dune.tmpl" ~value:backend_json
+      ~dir:(Node.Path.join [| project_directory; "backend" |])
+      ~to_json:(fun x -> x)
+  in
+  let+ _ = Template.compile backend_dune_template in
+
+  let readme_template =
+    Template.make ~name:"README.md.tmpl" ~value:backend_json
+      ~dir:(Node.Path.join [| project_directory; "backend" |])
+      ~to_json:(fun x -> x)
+  in
+  let+ _ = Template.compile readme_template in
+
+  Promise_result.resolve_ok ()
+;;
+
 let compile = Template.compile
 let node_pkg_manager_install = Npm.Install.exec
 let copy_git_ignore = Git_scm.Copy_gitignore.exec

src/core/react.ml

@@ -18,7 +18,7 @@ module Dune_project = struct
       Dependency.make "reason-react-ppx";
     ]
   ;;
-  
+
   let mlx_dependencies =
     [
       Dependency.make "mlx";