tools/patch-nextjs.js

/* eslint-disable @typescript-eslint/no-var-requires */
/* eslint-disable no-console */
const { dirname, join } = require('path');

const { writeFileSync, readFileSync } = require('fs');

/**
 * Replace content in a node module file
 * @param {string} moduleName - name of the module
 * @param {string} relativeFilePath - the relative path to the file inside the module
 * @param {RegExp} searchPattern - regular expression to search for the content to replace
 * @param {string} replacement - the content to replace with
 */
function replaceContentInNodeModule(
  next,
  relativeFilePath,
  searchPattern,
  replacement,
) {
  const modulePath = dirname(
    require.resolve(`../node_modules/${next}/package.json`),
  );
  const targetFilePath = join(modulePath, relativeFilePath);

  let updatedContent;
  try {
    const fileContent = readFileSync(targetFilePath, 'utf-8');
    updatedContent = fileContent.replaceAll(searchPattern, replacement);
  } catch (e) {
    console.error(`Error reading file: ${targetFilePath}`, e);
    throw e;
  }
  try {
    writeFileSync(targetFilePath, updatedContent, 'utf-8');
  } catch (e) {
    console.error(`Error writing updates to file: ${targetFilePath}`, e);
    throw e;
  }
  console.log(`Content replaced in file: ${targetFilePath}`);
}

replaceContentInNodeModule(
  'next',
  'dist/shared/lib/router/utils/path-has-prefix.js',
  'pathname === prefix',
  'pathname == prefix',
);

replaceContentInNodeModule(
  'next',
  'dist/server/config.js',
  'if (typeof result.basePath !== "string")',
  'if (false)',
);

replaceContentInNodeModule(
  'next',
  'dist/server/config.js',
  'if (!result.basePath.startsWith("/"))',
  'if (false)',
);
replaceContentInNodeModule(
  'next',
  'dist/build/webpack/loaders/next-font-loader/index.js',
  'if (assetPrefix && !/^\\/|https?:\\/\\//.test(assetPrefix))',
  'if (false)',
);

replaceContentInNodeModule(
  'next',
  'dist/lib/load-custom-routes.js',
  'if (config.basePath) {',
  'if (config.basePath.toString()) {',
);

replaceContentInNodeModule(
  'next-auth',
  'core/lib/callback-url.js',
  'baseUrl: url.origin',
  `baseUrl: '' + url.origin + (process.env.APP_BASE_PATH || '')`,
);

// Fix RxJs issue in innerFrom, when an observable is not recognized as an instance of Observable and throws an exception,
// although it has lift and subscribe methods, therefore it should be considered as an Observable
// as a workaround, here in the code is the factual replacement of "input instanceof Observable" with one-liner of "isObservable(input)"
replaceContentInNodeModule(
    'rxjs',
    'dist/esm/internal/observable/innerFrom.js',
    'if (input instanceof Observable) {',
    `if (!!input && (input instanceof Observable || (typeof input.lift === 'function' && typeof input.subscribe === 'function'))) {`,
);

replaceContentInNodeModule(
    'rxjs',
    'dist/esm5/internal/observable/innerFrom.js',
    'if (input instanceof Observable) {',
    `if (!!input && (input instanceof Observable || (typeof input.lift === 'function' && typeof input.subscribe === 'function'))) {`,
);

replaceContentInNodeModule(
    'rxjs',
    'dist/cjs/internal/observable/innerFrom.js',
    'if (input instanceof Observable_1.Observable) {',
    `if (!!input && (input instanceof Observable_1.Observable || (typeof input.lift === 'function' && typeof input.subscribe === 'function'))) {`,
);

// Enable server-side debugging in Next.js, enable to set 0.0.0.0 as host
replaceContentInNodeModule(
    'next',
    'dist/server/lib/utils.js',
    'return debugPortStr ? parseInt(debugPortStr, 10) : 9229;',
    'return debugPortStr ? debugPortStr : 9229;',
);

replaceContentInNodeModule(
    'next',
    'dist/esm/server/lib/utils.js',
    'return debugPortStr ? parseInt(debugPortStr, 10) : 9229;',
    'return debugPortStr ? debugPortStr : 9229;',
);

replaceContentInNodeModule(
    'next',
    'dist/cli/next-dev.js',
    'NODE_OPTIONS = `${NODE_OPTIONS} --${nodeDebugType}=${(0, _utils.getDebugPort)() + 1}`;',
    "NODE_OPTIONS = `${NODE_OPTIONS} --${nodeDebugType}=${((str) => str.includes(':') ? str.replace(/(\\d+)$/, num => ++num) : ++str)(String((0, _utils.getDebugPort)()))}`;",
);