[WIP] Stateful

generator/src/cli.js

@@ -344,25 +344,39 @@ async function requireElm(compiledElmPath) {
   const warnOriginal = console.warn;
   console.warn = function () {};
 
-  let Elm = (await import(url.pathToFileURL(path.resolve(compiledElmPath)).href)).default;
+  let Elm = (
+    await import(url.pathToFileURL(path.resolve(compiledElmPath)).href)
+  ).default;
   console.warn = warnOriginal;
   return Elm;
 }
 
 /**
+ * @param {string} expectedFilePath
  * @param {string} moduleName
  */
-function generatorWrapperFile(moduleName) {
+async function generatorWrapperFile(expectedFilePath, moduleName) {
+  const moduleContent = await fs.promises.readFile(expectedFilePath, {
+    encoding: "utf-8",
+  });
+
+  const hasRun = /^run\s*=/m.test(moduleContent);
+  const hasMain = /^main\s*=/m.test(moduleContent);
+
+  const { data, app } =
+    hasMain && !hasRun
+      ? { data: "main", app: "statefulApp" }
+      : { data: "run", app: "app" };
+
   return `port module ScriptMain exposing (main)
 
 import Pages.Internal.Platform.GeneratorApplication
 import ${moduleName}
 
 
-main : Pages.Internal.Platform.GeneratorApplication.Program
 main =
-    Pages.Internal.Platform.GeneratorApplication.app
-        { data = ${moduleName}.run
+    Pages.Internal.Platform.GeneratorApplication.${app}
+        { data = ${moduleName}.${data}
         , toJsPort = toJsPort
         , fromJsPort = fromJsPort identity
         , gotBatchSub = gotBatchSub identity
@@ -379,6 +393,11 @@ port fromJsPort : (Pages.Internal.Platform.GeneratorApplication.JsonValue -> msg
 port gotBatchSub : (Pages.Internal.Platform.GeneratorApplication.JsonValue -> msg) -> Sub msg
 `;
 }
+
+/**
+ * @param {any} value
+ * @param {any[]} previous
+ */
 function collect(value, previous) {
   return previous.concat([value]);
 }
@@ -406,7 +425,7 @@ async function compileElmForScript(elmModulePath) {
     path.join(
       `${projectDirectory}/elm-stuff/elm-pages/.elm-pages/ScriptMain.elm`
     ),
-    generatorWrapperFile(moduleName)
+    await generatorWrapperFile(expectedFilePath, moduleName)
   );
   let executableName = await lamderaOrElmFallback();
   try {

generator/src/render.js

@@ -544,6 +544,8 @@ async function runInternalJob(
         return [requestHash, runStartSpinner(requestToPerform)];
       case "elm-pages-internal://stop-spinner":
         return [requestHash, runStopSpinner(requestToPerform)];
+      case "elm-pages-internal://exit":
+        process.exit(requestToPerform.body.args[0]);
       default:
         throw `Unexpected internal BackendTask request format: ${kleur.yellow(
           JSON.stringify(2, null, requestToPerform)

src/Pages/GeneratorProgramConfig.elm

@@ -3,11 +3,11 @@ module Pages.GeneratorProgramConfig exposing (GeneratorProgramConfig)
 import Json.Decode as Decode
 import Json.Encode
 import Pages.Internal.Platform.ToJsPayload
-import Pages.Script exposing (Script)
+import Pages.Script exposing (StatefulScript)
 
 
-type alias GeneratorProgramConfig =
-    { data : Script
+type alias GeneratorProgramConfig model msg =
+    { data : StatefulScript model msg
     , toJsPort : Json.Encode.Value -> Cmd Never
     , fromJsPort : Sub Decode.Value
     , gotBatchSub : Sub Decode.Value