feat: add script hot-reload and compile-on-save

packages/backend/src/routes/build.ts

@@ -1,5 +1,9 @@
 import { Router } from "express";
-import { buildModule } from "../services/build.service.js";
+import {
+  buildModule,
+  hotReloadScripts,
+  compileSingle,
+} from "../services/build.service.js";
 
 const router = Router();
 
@@ -23,4 +27,24 @@ router.post("/module/pack", async (req, res) => {
   }
 });
 
+router.post("/deploy", async (_req, res) => {
+  try {
+    const result = await hotReloadScripts();
+    res.json(result);
+  } catch (err: any) {
+    res.status(500).json({ error: err.message });
+  }
+});
+
+router.post("/compile-single", async (req, res) => {
+  const { filePath } = req.body;
+  if (!filePath) return res.status(400).json({ error: "filePath required" });
+  try {
+    const result = await compileSingle(filePath);
+    res.json(result);
+  } catch (err: any) {
+    res.status(500).json({ error: err.message });
+  }
+});
+
 export default router;

packages/backend/src/services/build.service.ts

@@ -1,3 +1,5 @@
+import fs from "fs/promises";
+import path from "path";
 import { runEphemeralContainer } from "./docker.service.js";
 import {
   getWorkspacePath,
@@ -41,3 +43,53 @@ export async function buildModule(
 
   return { success, output: result.output };
 }
+
+export async function hotReloadScripts(): Promise<{
+  success: boolean;
+  output: string;
+  scripts: string[];
+}> {
+  const workspacePath = getWorkspacePath();
+
+  broadcast("build", "start", { type: "hot-reload" });
+
+  const result = await buildModule("bare", "compile");
+  if (!result.success) {
+    return { success: false, output: result.output, scripts: [] };
+  }
+
+  const cacheDir = path.join(
+    workspacePath,
+    "repos/nwn-module/.nasher/cache/bare",
+  );
+  const devDir = getServerPath("development");
+
+  let scripts: string[] = [];
+  try {
+    const files = await fs.readdir(cacheDir);
+    const ncsFiles = files.filter((f) => f.endsWith(".ncs"));
+
+    await fs.mkdir(devDir, { recursive: true });
+    for (const ncs of ncsFiles) {
+      await fs.copyFile(path.join(cacheDir, ncs), path.join(devDir, ncs));
+      scripts.push(ncs);
+    }
+  } catch {
+    // cache dir may not exist yet
+  }
+
+  broadcast("build", "complete", { type: "hot-reload", scripts });
+  return { success: true, output: result.output, scripts };
+}
+
+export async function compileSingle(
+  filePath: string,
+): Promise<{ success: boolean; errors: string[] }> {
+  const result = await buildModule("bare", "compile");
+  const errors = result.output
+    .split("\n")
+    .filter((line) => line.toLowerCase().includes("error"))
+    .map((line) => line.trim());
+
+  return { success: result.success, errors };
+}