xref: /expo/packages/@expo/cli/src/start/server/metro/router.ts (revision 46f023fa)

import { ExpoConfig } from '@expo/config';
import chalk from 'chalk';
import { sync as globSync } from 'glob';
import path from 'path';
import resolveFrom from 'resolve-from';

import { Log } from '../../../log';
import { directoryExistsSync } from '../../../utils/dir';

const debug = require('debug')('expo:start:server:metro:router') as typeof console.log;

/**
 * Get the relative path for requiring the `/app` folder relative to the `expo-router/entry` file.
 * This mechanism does require the server to restart after the `expo-router` package is installed.
 */
export function getAppRouterRelativeEntryPath(
  projectRoot: string,
  routerDirectory: string = getRouterDirectory(projectRoot)
): string | undefined {
  // Auto pick App entry
  const routerEntry =
    resolveFrom.silent(projectRoot, 'expo-router/entry') ?? getFallbackEntryRoot(projectRoot);
  if (!routerEntry) {
    return undefined;
  }
  // It doesn't matter if the app folder exists.
  const appFolder = path.join(projectRoot, routerDirectory);
  const appRoot = path.relative(path.dirname(routerEntry), appFolder);
  debug('routerEntry', routerEntry, appFolder, appRoot);
  return appRoot;
}

/** If the `expo-router` package is not installed, then use the `expo` package to determine where the node modules are relative to the project. */
function getFallbackEntryRoot(projectRoot: string): string {
  const expoRoot = resolveFrom.silent(projectRoot, 'expo/package.json');
  if (expoRoot) {
    return path.join(path.dirname(path.dirname(expoRoot)), 'expo-router/entry');
  }
  return path.join(projectRoot, 'node_modules/expo-router/entry');
}

export function getRouterDirectoryModuleIdWithManifest(
  projectRoot: string,
  exp: ExpoConfig
): string {
  return exp.extra?.router?.unstable_src ?? getRouterDirectory(projectRoot);
}

export function getRouterDirectoryWithManifest(projectRoot: string, exp: ExpoConfig): string {
  return path.join(projectRoot, getRouterDirectoryModuleIdWithManifest(projectRoot, exp));
}

export function getRouterDirectory(projectRoot: string): string {
  // more specific directories first
  if (directoryExistsSync(path.join(projectRoot, 'src/app'))) {
    Log.log(chalk.gray('Using src/app as the root directory for Expo Router.'));
    return 'src/app';
  }

  Log.debug('Using app as the root directory for Expo Router.');
  return 'app';
}

export function isApiRouteConvention(name: string): boolean {
  return /\+api\.[tj]sx?$/.test(name);
}

export function getApiRoutesForDirectory(cwd: string) {
  return globSync('**/*+api.@(ts|tsx|js|jsx)', {
    cwd,
    absolute: true,
  });
}

// Used to emulate a context module, but way faster. TODO: May need to adjust the extensions to stay in sync with Metro.
export function getRoutePaths(cwd: string) {
  return globSync('**/*.@(ts|tsx|js|jsx)', {
    cwd,
  }).map((p) => './' + normalizePaths(p));
}

function normalizePaths(p: string) {
  return p.replace(/\\/g, '/');
}