export default defineConfig({
- testDir: "./tests",
+ testMatch: "app/routes/**/*.spec.ts",

// testMatch: "./app/routes/**/*.spec.ts", // この書き方はしない！

Error: No tests found
 ELIFECYCLE  Test failed. See above for more details.

pnpm add -D vitest jsdom

{
  "scripts": {
+   "vitest:development": "vitest --mode development",

import * as path from "node:path";
import * as VitestConfig from "vitest/config";

export default VitestConfig.defineConfig({
  test: {
    globals: true,
    environment: "jsdom",
    include: ["**/*.test.?(c|m)[jt]s?(x)"],
  },
  define: {
    "import.meta.vitest": false,
  },
  resolve: {
    alias: {
      "~": path.resolve(__dirname, "app"),
      db: path.resolve(__dirname, "db"),
    },
  },
});

Error: Failed to resolve import "db" from "app/routes/_index/hoge.server.ts". Does the file exist?
  Plugin: vite:import-analysis
  File: /appName/app/routes/_index/hoge.server.ts:1:19
  1  |  import { db } from "db";
     |                      ^

  "compilerOptions": {
    "types": [
      // vite.config.ts の `globals: true, ` に加えてここを設定することで各ファイルでimportする必要がなくなる
+     "vitest/globals",
      // import.meta.env を使うために入れたがなくても動く
+     "vitest/importMeta",
    ],

pnpm add sharp

+ import sharp from "sharp";

export async function action({ request, context }: ActionFunctionArgs) {
  const formData = await request.formData();
  const submission = parseWithZod(formData, { schema });
  const lastResult = submission.reply();

  const key = `contents/${crypto.randomUUID()}`;
  const file = submission.value.file;

  // ファイルをBufferとして読み取る
+ const arrayBuffer = await file.arrayBuffer();
+ const buffer = Buffer.from(arrayBuffer);

  // AVIF形式に変換
+ const avifBuffer = await sharp(buffer).toFormat("avif").toBuffer();

+ const response = await context.cloudflare.env.BUCKET.put(key, avifBuffer);
  const url = `${context.cloudflare.env.R2_DOMAIN}/${response?.key}`;
  return successJson<R2UploadResponse>({ lastResult, data: { url } });
}

▲ [WARNING] The package "node:util" wasn't found on the file system but is built into node.
▲ [WARNING] The package "node:events" wasn't found on the file system but is built into node.
▲ [WARNING] The package "node:path" wasn't found on the file system but is built into node.
▲ [WARNING] The package "node:stream" wasn't found on the file system but is built into node.
▲ [WARNING] The package "node:child_process" wasn't found on the file system but is built into node.
▲ [WARNING] The package "node:crypto" wasn't found on the file system but is built into node.
▲ [WARNING] The package "node:os" wasn't found on the file system but is built into node.
  Your Worker may throw errors at runtime unless you enable the "nodejs_compat" compatibility flag.
  Refer to https://developers.cloudflare.com/workers/runtime-apis/nodejs/ for more details. Imported
  from:
   - node_modules/.pnpm/sharp@0.33.5/node_modules/sharp/lib/utility.js

✘ [ERROR] Build failed with 2 errors:
  ✘ [ERROR] Could not resolve "child_process"  
      node_modules/.pnpm/detect-libc@2.0.3/node_modules/detect-libc/lib/detect-libc.js:6:29:
        6 │ const childProcess = require('child_process');
          ╵                              ~~~~~~~~~~~~~~~
  
    The package "child_process" wasn't found on the file system but is built into node.
    - Add the "nodejs_compat" compatibility flag to your project.  
  
  ✘ [ERROR] Could not resolve "fs"  
      node_modules/.pnpm/detect-libc@2.0.3/node_modules/detect-libc/lib/filesystem.js:6:19:
        6 │ const fs = require('fs');
          ╵                    ~~~~
  
    The package "fs" wasn't found on the file system but is built into node.
    - Add the "nodejs_compat" compatibility flag to your project.