Updated the files.

my-app/node_modules/yargs/lib/platform-shims/browser.mjs

@@ -0,0 +1,95 @@
+/* eslint-disable no-unused-vars */
+'use strict';
+
+import cliui from 'https://unpkg.com/cliui@7.0.1/index.mjs'; // eslint-disable-line
+import Parser from 'https://unpkg.com/yargs-parser@19.0.0/browser.js'; // eslint-disable-line
+import {getProcessArgvBin} from '../../build/lib/utils/process-argv.js';
+import {YError} from '../../build/lib/yerror.js';
+
+const REQUIRE_ERROR = 'require is not supported in browser';
+const REQUIRE_DIRECTORY_ERROR =
+  'loading a directory of commands is not supported in browser';
+
+export default {
+  assert: {
+    notStrictEqual: (a, b) => {
+      // noop.
+    },
+    strictEqual: (a, b) => {
+      // noop.
+    },
+  },
+  cliui,
+  findUp: () => undefined,
+  getEnv: key => {
+    // There is no environment in browser:
+    return undefined;
+  },
+  inspect: console.log,
+  getCallerFile: () => {
+    throw new YError(REQUIRE_DIRECTORY_ERROR);
+  },
+  getProcessArgvBin,
+  mainFilename: 'yargs',
+  Parser,
+  path: {
+    basename: str => str,
+    dirname: str => str,
+    extname: str => str,
+    relative: str => str,
+  },
+  process: {
+    argv: () => [],
+    cwd: () => '',
+    emitWarning: (warning, name) => {},
+    execPath: () => '',
+    // exit is noop browser:
+    exit: () => {},
+    nextTick: cb => {
+      // eslint-disable-next-line no-undef
+      window.setTimeout(cb, 1);
+    },
+    stdColumns: 80,
+  },
+  readFileSync: () => {
+    return '';
+  },
+  require: () => {
+    throw new YError(REQUIRE_ERROR);
+  },
+  requireDirectory: () => {
+    throw new YError(REQUIRE_DIRECTORY_ERROR);
+  },
+  stringWidth: str => {
+    return [...str].length;
+  },
+  // TODO: replace this with y18n once it's ported to ESM:
+  y18n: {
+    __: (...str) => {
+      if (str.length === 0) return '';
+      const args = str.slice(1);
+      return sprintf(str[0], ...args);
+    },
+    __n: (str1, str2, count, ...args) => {
+      if (count === 1) {
+        return sprintf(str1, ...args);
+      } else {
+        return sprintf(str2, ...args);
+      }
+    },
+    getLocale: () => {
+      return 'en_US';
+    },
+    setLocale: () => {},
+    updateLocale: () => {},
+  },
+};
+
+function sprintf(_str, ...args) {
+  let str = '';
+  const split = _str.split('%s');
+  split.forEach((token, i) => {
+    str += `${token}${split[i + 1] !== undefined && args[i] ? args[i] : ''}`;
+  });
+  return str;
+}

my-app/node_modules/yargs/lib/platform-shims/esm.mjs

@@ -0,0 +1,73 @@
+'use strict'
+
+import { notStrictEqual, strictEqual } from 'assert'
+import cliui from 'cliui'
+import escalade from 'escalade/sync'
+import { inspect } from 'util'
+import { readFileSync } from 'fs'
+import { fileURLToPath } from 'url';
+import Parser from 'yargs-parser'
+import { basename, dirname, extname, relative, resolve } from 'path'
+import { getProcessArgvBin } from '../../build/lib/utils/process-argv.js'
+import { YError } from '../../build/lib/yerror.js'
+import y18n from 'y18n'
+
+const REQUIRE_ERROR = 'require is not supported by ESM'
+const REQUIRE_DIRECTORY_ERROR = 'loading a directory of commands is not supported yet for ESM'
+
+let __dirname;
+try {
+  __dirname = fileURLToPath(import.meta.url);
+} catch (e) {
+  __dirname = process.cwd();
+}
+const mainFilename = __dirname.substring(0, __dirname.lastIndexOf('node_modules'));
+
+export default {
+  assert: {
+    notStrictEqual,
+    strictEqual
+  },
+  cliui,
+  findUp: escalade,
+  getEnv: (key) => {
+    return process.env[key]
+  },
+  inspect,
+  getCallerFile: () => {
+    throw new YError(REQUIRE_DIRECTORY_ERROR)
+  },
+  getProcessArgvBin,
+  mainFilename: mainFilename || process.cwd(),
+  Parser,
+  path: {
+    basename,
+    dirname,
+    extname,
+    relative,
+    resolve
+  },
+  process: {
+    argv: () => process.argv,
+    cwd: process.cwd,
+    emitWarning: (warning, type) => process.emitWarning(warning, type),
+    execPath: () => process.execPath,
+    exit: process.exit,
+    nextTick: process.nextTick,
+    stdColumns: typeof process.stdout.columns !== 'undefined' ? process.stdout.columns : null
+  },
+  readFileSync,
+  require: () => {
+    throw new YError(REQUIRE_ERROR)
+  },
+  requireDirectory: () => {
+    throw new YError(REQUIRE_DIRECTORY_ERROR)
+  },
+  stringWidth: (str) => {
+    return [...str].length
+  },
+  y18n: y18n({
+    directory: resolve(__dirname, '../../../locales'),
+    updateFiles: false
+  })
+}