expo-web-browser/plugin/src/withWebBrowserAndroid.ts

Provides access to the system's web browser and supports handling redirects. On iOS, it uses SFSafariViewController or ASWebAuthenticationSession, depending on the method you call, and on Android it uses ChromeCustomTabs. As of iOS 11, SFSafariViewControl

import type { ExpoConfig } from 'expo/config';
import {
  AndroidConfig,
  ConfigPlugin,
  withAndroidManifest,
  withDangerousMod,
} from 'expo/config-plugins';
import fs from 'fs';
import path from 'path';

export type PluginConfig = {
  experimentalLauncherActivity?: boolean;
};

export const withWebBrowserAndroid: ConfigPlugin = (config) => {
  config = addActivityToManifest(config);
  config = addLauncherClassToProject(config);

  return config;
};

function addActivityToManifest(config: ExpoConfig) {
  return withAndroidManifest(config, (config) => {
    const manifest = config.modResults.manifest;
    const application = manifest?.application?.[0];

    for (const activity of application?.activity ?? []) {
      if (activity.$['android:name'] === '.BrowserLauncherActivity') {
        return config;
      }
    }

    const theme = application?.activity?.[0]?.$['android:theme'];
    application?.activity?.[0]?.['intent-filter']?.splice(0, 1);

    const launcherActivity: AndroidConfig.Manifest.ManifestActivity = {
      $: {
        'android:name': '.BrowserLauncherActivity',
        'android:theme': theme,
        'android:exported': 'true',
      },
      'intent-filter': [
        {
          action: [{ $: { 'android:name': 'android.intent.action.MAIN' } }],
          category: [{ $: { 'android:name': 'android.intent.category.LAUNCHER' } }],
        },
      ],
    };

    application?.activity?.push(launcherActivity);
    return config;
  });
}

function addLauncherClassToProject(config: ExpoConfig) {
  return withDangerousMod(config, [
    'android',
    async (config) => {
      const fileName = 'BrowserLauncherActivity.kt';
      const dir = path.dirname(
        AndroidConfig.Paths.getProjectFilePath(config.modRequest.projectRoot, 'MainApplication')
      );

      const fullPath = path.join(dir, fileName);

      if (fs.existsSync(fullPath)) {
        return config;
      }

      const classTemplate = `package ${config.android?.package || ''}

import android.app.Activity
import android.content.Intent
import android.os.Bundle

class BrowserLauncherActivity : Activity() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    startActivity(
      Intent(intent).apply {
        setClassName(
          this@BrowserLauncherActivity,
          MainActivity::class.java.name
        )
      }
    )
    finish()
  }
}
`;

      await fs.promises.writeFile(fullPath, classTemplate);
      return config;
    },
  ]);
}