add command to build and run OpenNext locally with dev overrides

.changeset/seven-dodos-draw.md

@@ -0,0 +1,5 @@
+---
+"@opennextjs/aws": patch
+---
+
+feature: add cli commands to build and run OpenNext locally with dev overrides

packages/open-next/src/build/constant.ts

@@ -1,3 +1,35 @@
 //TODO: Move all other manifest path here as well
 export const MIDDLEWARE_TRACE_FILE = "server/middleware.js.nft.json";
 export const INSTRUMENTATION_TRACE_FILE = "server/instrumentation.js.nft.json";
+
+export const LOCAL_CONFIG_PATH = "./open-next.config.local.ts";
+/**
+ * https://opennext.js.org/aws/contribute/local_run
+ * This is an OpenNext config to run the default server function locally
+ * Be aware that this will not work the same way as in production.
+ * Its mostly used for debugging and development purposes.
+ */
+export const LOCAL_CONFIG = `export default {
+  default: {
+    override: {
+      wrapper: "express-dev",
+      converter: "node",
+      incrementalCache: "fs-dev",
+      queue: "direct",
+      tagCache: "fs-dev",
+    },
+  },
+  imageOptimization: {
+    override: {
+      wrapper: "dummy",
+      converter: "dummy",
+    },
+    loader: "fs-dev",
+    // This part is not needed on ARM Linux as it will be installed by default
+    // Remember to change this depending on your arch and system
+    install: {
+      arch: "x64",
+      packages: ["sharp"],
+    },
+  },
+}`;

packages/open-next/src/index.ts

@@ -1,15 +1,34 @@
 #!/usr/bin/env node
+import { spawnSync } from "node:child_process";
+import { existsSync, writeFileSync } from "node:fs";
+import path from "node:path";
 
 import { build } from "./build.js";
+import { LOCAL_CONFIG, LOCAL_CONFIG_PATH } from "./build/constant.js";
+import { printHeader } from "./build/utils.js";
 
 const command = process.argv[2];
-if (command !== "build") printHelp();
+const stage = process.argv[3];
+const validCommand =
+  command === "build" ||
+  command === "preview" ||
+  (command === "generate" && stage === "local");
+
+if (!validCommand) {
+  printHelp();
+}
 
 const args = parseArgs();
 if (Object.keys(args).includes("--help")) printHelp();
 
-await build(args["--config-path"], args["--node-externals"]);
-
+if (command === "build") {
+  await build(args["--config-path"], args["--node-externals"]);
+} else if (command === "generate" && stage === "local") {
+  generateLocalConfig();
+} else if (command === "preview") {
+  await buildLocalConfig();
+  runLocally();
+}
 function parseArgs() {
   return process.argv.slice(2).reduce(
     (acc, key, ind, self) => {
@@ -29,20 +48,87 @@ function parseArgs() {
   );
 }
 
+async function buildLocalConfig() {
+  if (!existsSync(LOCAL_CONFIG_PATH)) {
+    console.error(
+      "open-next.config.local.ts does not exist. You can run `generate local` first to generate it.",
+    );
+    process.exit(1);
+  }
+
+  // Build OpenNext with dev overrides
+  printHeader("Building OpenNext with open-next.config.local.ts");
+  await build(LOCAL_CONFIG_PATH, args["--node-externals"]);
+}
+
+function runLocally() {
+  const handlerPath = path.join(
+    ".open-next",
+    "server-functions",
+    "default",
+    "index.mjs",
+  );
+  if (!existsSync(handlerPath)) {
+    console.error(
+      "OpenNext server function not found. Please build it before running this command.",
+    );
+    process.exit(1);
+  }
+  printHeader("Running OpenNext locally");
+  spawnSync("node", [handlerPath], {
+    stdio: "inherit",
+    shell: true,
+  });
+}
+
+function generateLocalConfig() {
+  if (existsSync(LOCAL_CONFIG_PATH)) {
+    console.error(
+      "open-next.config.local.ts already exists. Please remove it before running this command.",
+    );
+    process.exit(1);
+  }
+
+  try {
+    writeFileSync(LOCAL_CONFIG_PATH, LOCAL_CONFIG);
+  } catch (e) {
+    console.error("Error writing open-next.config.local.ts", e);
+  }
+}
+
 function printHelp() {
-  console.log("Unknown command");
-  console.log("");
+  console.log("╔══════════════════════════════════════════╗");
+  console.log("║             Unknown Command              ║");
+  console.log("╚══════════════════════════════════════════╝\n");
+
   console.log("Usage:");
   console.log("  npx open-next build");
-  console.log("You can use a custom config path here");
+  console.log("      Build the project with OpenNext.\n");
+
+  console.log("Options:");
+  console.log("  --config-path <path>");
+  console.log("      Use a custom config path.");
   console.log(
-    "  npx open-next build --config-path ./path/to/open-next.config.ts",
+    "      Usage: npx open-next build --config-path ./path/to/open-next.config.ts\n",
   );
+
+  console.log("  --node-externals <modules>");
+  console.log("      Configure externals for the esbuild compilation of the");
+  console.log("      open-next.config.ts file.");
+  console.log(
+    "      Usage: npx open-next build --node-externals aws-sdk,sharp,sqlite3\n",
+  );
+
+  console.log("Other commands:");
+  console.log("  preview");
+  console.log(
+    "      Build and run OpenNext locally with open-next.config.local.ts",
+  );
+
+  console.log("  generate local");
   console.log(
-    "You can configure externals for the esbuild compilation of the open-next.config.ts file",
+    "      Generate a config file with dev overrides for OpenNext in open-next.config.local.ts",
   );
-  console.log("  npx open-next build --node-externals aws-sdk,sharp,sqlite3");
-  console.log("");
 
   process.exit(1);
 }