Split build.ts (#562)

Author: vicb

packages/open-next/src/build.ts

@@ -0,0 +1,24 @@
+import cp from "node:child_process";
+import path from "node:path";
+
+import * as buildHelper from "./helper.js";
+
+export function setStandaloneBuildMode(options: buildHelper.BuildOptions) {
+  // Equivalent to setting `output: "standalone"` in next.config.js
+  process.env.NEXT_PRIVATE_STANDALONE = "true";
+  // Equivalent to setting `experimental.outputFileTracingRoot` in next.config.js
+  process.env.NEXT_PRIVATE_OUTPUT_TRACE_ROOT = options.monorepoRoot;
+}
+
+export function buildNextjsApp(options: buildHelper.BuildOptions) {
+  const { config, packager } = options;
+  const command =
+    config.buildCommand ??
+    (["bun", "npm"].includes(packager)
+      ? `${packager} run build`
+      : `${packager} build`);
+  cp.execSync(command, {
+    stdio: "inherit",
+    cwd: path.dirname(options.appPackageJsonPath),
+  });
+}

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

@@ -1,4 +1,4 @@
-import { createRequire as topLevelCreateRequire } from "node:module";
+import { createRequire } from "node:module";
 
 import { build } from "esbuild";
 import path from "path";
@@ -43,7 +43,7 @@ const externals = [
 ];
 
 export async function bundleNextServer(outputDir: string, appPath: string) {
-  const require = topLevelCreateRequire(`${appPath}/package.json`);
+  const require = createRequire(`${appPath}/package.json`);
   const entrypoint = require.resolve("next/dist/esm/server/next-server.js");
 
   await build({

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

@@ -0,0 +1,45 @@
+import path from "node:path";
+
+import * as buildHelper from "./helper.js";
+
+/**
+ * Compiles the cache adapter.
+ *
+ * @param options Build options.
+ * @param format Output format.
+ * @returns The path to the compiled file.
+ */
+export function compileCache(
+  options: buildHelper.BuildOptions,
+  format: "cjs" | "esm" = "cjs",
+) {
+  const { config } = options;
+  const ext = format === "cjs" ? "cjs" : "mjs";
+  const outFile = path.join(options.buildDir, `cache.${ext}`);
+
+  const isAfter15 =
+    buildHelper.compareSemver(options.nextVersion, "15.0.0") >= 0;
+
+  buildHelper.esbuildSync(
+    {
+      external: ["next", "styled-jsx", "react", "@aws-sdk/*"],
+      entryPoints: [path.join(options.openNextDistDir, "adapters", "cache.js")],
+      outfile: outFile,
+      target: ["node18"],
+      format,
+      banner: {
+        js: [
+          `globalThis.disableIncrementalCache = ${
+            config.dangerous?.disableIncrementalCache ?? false
+          };`,
+          `globalThis.disableDynamoDBCache = ${
+            config.dangerous?.disableTagCache ?? false
+          };`,
+          `globalThis.isNextAfter15 = ${isAfter15};`,
+        ].join(""),
+      },
+    },
+    options,
+  );
+  return outFile;
+}

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

@@ -1,20 +1,74 @@
 import fs from "node:fs";
+import os from "node:os";
 import path from "node:path";
 
 import { buildSync } from "esbuild";
 import { OpenNextConfig } from "types/open-next.js";
 
 import logger from "../logger.js";
+import { validateConfig } from "./validateConfig.js";
 
-export function compileOpenNextConfigNode(
-  outputDir: string,
+/**
+ * Compiles the OpenNext configuration.
+ *
+ * The configuration is always compiled for Node.js and for the edge only if needed.
+ *
+ * @param baseDir Directory where to look for the configuration.
+ * @param openNextConfigPath Override the default configuration when provided. Relative to baseDir.
+ * @param nodeExternals Externals for the Node.js compilation.
+ * @return The configuration and the build directory.
+ */
+export async function compileOpenNextConfig(
+  baseDir: string,
   openNextConfigPath?: string,
   nodeExternals?: string,
 ) {
   const sourcePath = path.join(
-    process.cwd(),
+    baseDir,
     openNextConfigPath ?? "open-next.config.ts",
   );
+
+  const buildDir = fs.mkdtempSync(path.join(os.tmpdir(), "open-next-tmp"));
+  let configPath = compileOpenNextConfigNode(
+    sourcePath,
+    buildDir,
+    nodeExternals ? nodeExternals.split(",") : [],
+  );
+
+  // On Windows, we need to use file:// protocol to load the config file using import()
+  if (process.platform === "win32") configPath = `file://${configPath}`;
+  const config = (await import(configPath)).default as OpenNextConfig;
+  if (!config || !config.default) {
+    logger.error(
+      `config.default cannot be empty, it should be at least {}, see more info here: https://open-next.js.org/config#configuration-file`,
+    );
+    process.exit(1);
+  }
+
+  validateConfig(config);
+
+  // We need to check if the config uses the edge runtime at any point
+  // If it does, we need to compile it with the edge runtime
+  const usesEdgeRuntime =
+    config.middleware?.external ||
+    Object.values(config.functions || {}).some((fn) => fn.runtime === "edge");
+  if (!usesEdgeRuntime) {
+    logger.debug(
+      "No edge runtime found in the open-next.config.ts. Using default config.",
+    );
+    //Nothing to do here
+  } else {
+    compileOpenNextConfigEdge(sourcePath, buildDir, config.edgeExternals ?? []);
+  }
+
+  return { config, buildDir };
+}
+
+export function compileOpenNextConfigNode(
+  sourcePath: string,
+  outputDir: string,
+  externals: string[],
+) {
   const outputPath = path.join(outputDir, "open-next.config.mjs");
 
   //Check if open-next.config.ts exists
@@ -29,7 +83,7 @@ export function compileOpenNextConfigNode(
       bundle: true,
       format: "esm",
       target: ["node18"],
-      external: nodeExternals ? nodeExternals.split(",") : [],
+      external: externals,
       platform: "node",
       banner: {
         js: [
@@ -46,38 +100,22 @@ export function compileOpenNextConfigNode(
 }
 
 export function compileOpenNextConfigEdge(
-  tempDir: string,
-  config: OpenNextConfig,
-  openNextConfigPath?: string,
+  sourcePath: string,
+  outputDir: string,
+  externals: string[],
 ) {
-  const sourcePath = path.join(
-    process.cwd(),
-    openNextConfigPath ?? "open-next.config.ts",
-  );
-  const outputPath = path.join(tempDir, "open-next.config.edge.mjs");
+  const outputPath = path.join(outputDir, "open-next.config.edge.mjs");
 
-  // We need to check if the config uses the edge runtime at any point
-  // If it does, we need to compile it with the edge runtime
-  const usesEdgeRuntime =
-    config.middleware?.external ||
-    Object.values(config.functions || {}).some((fn) => fn.runtime === "edge");
-  if (!usesEdgeRuntime) {
-    logger.debug(
-      "No edge runtime found in the open-next.config.ts. Using default config.",
-    );
-    //Nothing to do here
-  } else {
-    logger.info("Compiling open-next.config.ts for edge runtime.", outputPath);
-    buildSync({
-      entryPoints: [sourcePath],
-      outfile: outputPath,
-      bundle: true,
-      format: "esm",
-      target: ["es2020"],
-      conditions: ["worker", "browser"],
-      platform: "browser",
-      external: config.edgeExternals ?? [],
-    });
-    logger.info("Compiled open-next.config.ts for edge runtime.");
-  }
+  logger.info("Compiling open-next.config.ts for edge runtime.", outputPath);
+  buildSync({
+    entryPoints: [sourcePath],
+    outfile: outputPath,
+    bundle: true,
+    format: "esm",
+    target: ["es2020"],
+    conditions: ["worker", "browser"],
+    platform: "browser",
+    external: externals,
+  });
+  logger.info("Compiled open-next.config.ts for edge runtime.");
 }