Copy resources into output directory instead of moving them. (#363)

This is part of making the adapter idempotent.

Author: annajowang

packages/@apphosting/adapter-nextjs/src/bin/build.spec.ts

@@ -32,6 +32,10 @@ describe("build commands", () => {
   it("expects all output bundle files to be generated", async () => {
     const { generateBuildOutput, validateOutputDirectory } = await importUtils;
     const files = {
+      // .next/standalone/.next/ must be created beforehand otherwise
+      // generateBuildOutput will attempt to copy
+      // .next/ into .next/standalone/.next
+      ".next/standalone/.next/package.json": "",
       ".next/standalone/server.js": "",
       ".next/static/staticfile": "",
       ".next/routes-manifest.json": `{
@@ -53,7 +57,13 @@ describe("build commands", () => {
 
     const expectedFiles = {
       ".next/standalone/.next/static/staticfile": "",
+      ".next/static/staticfile": "",
       ".next/standalone/server.js": "",
+      ".next/routes-manifest.json": `{
+        "headers":[],
+        "rewrites":[],
+        "redirects":[]
+      }`,
       ".apphosting/bundle.yaml": `version: v1
 runConfig:
   runCommand: node .next/standalone/server.js
@@ -71,7 +81,7 @@ outputFiles:
     validateTestFiles(tmpDir, expectedFiles);
   });
 
-  it("moves files into correct location in a monorepo setup", async () => {
+  it("copies files into correct location in a monorepo setup", async () => {
     const { generateBuildOutput } = await importUtils;
     const files = {
       ".next/standalone/apps/next-app/standalonefile": "",
@@ -113,6 +123,7 @@ outputFiles:
     const expectedFiles = {
       ".next/standalone/apps/next-app/.next/static/staticfile": "",
       ".next/standalone/apps/next-app/standalonefile": "",
+      ".next/static/staticfile": "",
     };
     const expectedPartialYaml = {
       version: "v1",
@@ -125,6 +136,10 @@ outputFiles:
   it("test failed validateOutputDirectory", async () => {
     const { generateBuildOutput, validateOutputDirectory } = await importUtils;
     const files = {
+      // .next/standalone/.next/ must be created beforehand otherwise
+      // generateBuildOutput will attempt to copy
+      // .next/ into .next/standalone/.next
+      ".next/standalone/.next/package.json": "",
       ".next/standalone/notserver.js": "",
       ".next/static/staticfile": "",
       ".next/routes-manifest.json": `{
@@ -152,6 +167,10 @@ outputFiles:
   it("expects directories and other files to be copied over", async () => {
     const { generateBuildOutput, validateOutputDirectory } = await importUtils;
     const files = {
+      // .next/standalone/.next/ must be created beforehand otherwise
+      // generateBuildOutput will attempt to copy
+      // .next/ into .next/standalone/.next
+      ".next/standalone/.next/package.json": "",
       ".next/standalone/server.js": "",
       ".next/static/staticfile": "",
       "public/publicfile": "",
@@ -178,9 +197,15 @@ outputFiles:
 
     const expectedFiles = {
       ".next/standalone/.next/static/staticfile": "",
+      ".next/static/staticfile": "",
       ".next/standalone/server.js": "",
       ".next/standalone/public/publicfile": "",
       ".next/standalone/extrafile": "",
+      ".next/routes-manifest.json": `{
+        "headers":[],
+        "rewrites":[],
+        "redirects":[]
+      }`,
     };
     validateTestFiles(tmpDir, expectedFiles);
   });

packages/@apphosting/adapter-nextjs/src/utils.ts

@@ -15,7 +15,7 @@ import { NextConfigComplete } from "next/dist/server/config-shared.js";
 import { OutputBundleConfig } from "@apphosting/common";
 
 // fs-extra is CJS, readJson can't be imported using shorthand
-export const { move, exists, writeFile, readJson, readdir, readFileSync, existsSync, mkdir } =
+export const { copy, exists, writeFile, readJson, readdir, readFileSync, existsSync, mkdir } =
   fsExtra;
 
 // Loads the user's next.config.js file.
@@ -116,7 +116,7 @@ export function populateOutputBundleOptions(
 }
 
 /**
- * Moves static assets and other resources into the standlone directory, also generates the bundle.yaml
+ * Copy static assets and other resources into the standlone directory, also generates the bundle.yaml
  * @param rootDir The root directory of the uploaded source code.
  * @param outputBundleOptions The target location of built artifacts in the output bundle.
  * @param nextBuildDirectory The location of the .next directory.
@@ -131,30 +131,30 @@ export async function generateBuildOutput(
 ): Promise<void> {
   const staticDirectory = join(nextBuildDirectory, "static");
   await Promise.all([
-    move(staticDirectory, opts.outputStaticDirectoryPath, { overwrite: true }),
-    moveResources(appDir, opts.outputDirectoryAppPath, opts.bundleYamlPath),
+    copy(staticDirectory, opts.outputStaticDirectoryPath, { overwrite: true }),
+    copyResources(appDir, opts.outputDirectoryAppPath, opts.bundleYamlPath),
     generateBundleYaml(opts, rootDir, nextVersion, adapterMetadata),
   ]);
   return;
 }
 
-// Move all files and directories to apphosting output directory.
+// Copy all files and directories to apphosting output directory.
 // Files are skipped if there is already a file with the same name in the output directory
-async function moveResources(
+async function copyResources(
   appDir: string,
   outputBundleAppDir: string,
   bundleYamlPath: string,
 ): Promise<void> {
   const appDirExists = await exists(appDir);
   if (!appDirExists) return;
-  const pathsToMove = await readdir(appDir);
-  for (const path of pathsToMove) {
+  const pathsToCopy = await readdir(appDir);
+  for (const path of pathsToCopy) {
     const isbundleYamlDir = join(appDir, path) === dirname(bundleYamlPath);
     const existsInOutputBundle = await exists(join(outputBundleAppDir, path));
     // Keep apphosting.yaml files in the root directory still, as later steps expect them to be there
     const isApphostingYaml = path === "apphosting_preprocessed" || path === "apphosting.yaml";
     if (!isbundleYamlDir && !existsInOutputBundle && !isApphostingYaml) {
-      await move(join(appDir, path), join(outputBundleAppDir, path));
+      await copy(join(appDir, path), join(outputBundleAppDir, path));
     }
   }
   return;